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1.
Hum Reprod ; 33(5): 914-918, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29538680

RESUMO

Testotoxicosis is a rare cause of peripheral precocious puberty in boys caused by constitutively activating mutations of the LHCG receptor. Affected males usually have normal gonadotropin profiles and fertility in their adult life. Here, we described the long-term follow-up of a 24-year-old young man with severe testotoxicosis due to a de novo activating mutation in the third transmembrane helix of the LHCGR (p.Leu457Arg). This patient was treated with different medications, including medroxyprogesterone acetate, ketoconazole, cyproterone acetate and aromatase inhibitor from age 2.5 to 9.5 years. His basal and GnRH-stimulated gonadotropin levels were continually suppressed during and after medical treatment. At adulthood, extremely high serum testosterone levels (>35 nmol/L), undetectable gonadotropin levels (LH < 0.15 IU/L and FSH < 0.6 IU/L) and oligozoospermia were evidenced. Despite his suppressed FSH levels and an unfavorable spermogram, the patient fathered a healthy girl and biological paternity was confirmed through analysis of microsatellites. Spontaneous fertility in a young man with severe testotoxicosis and chronic suppression of FSH levels reinforces the key role of high intratesticular testosterone levels in human spermatogenesis.


Assuntos
Fertilidade/genética , Puberdade Precoce/genética , Receptores do LH/genética , Testosterona/sangue , Adulto , Humanos , Masculino , Mutação , Puberdade Precoce/sangue
2.
Pharmacogenomics J ; 12(5): 439-45, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21468024

RESUMO

Insulin-like growth factor type 1 (IGF1) is a mediator of growth hormone (GH) action, and therefore, IGF1 is a candidate gene for recombinant human GH (rhGH) pharmacogenetics. Lower serum IGF1 levels were found in adults homozygous for 19 cytosine-adenosine (CA) repeats in the IGF1 promoter. The aim of this study was to evaluate the influence of (CA)n IGF1 polymorphism, alone or in combination with GH receptor (GHR)-exon 3 and -202 A/C insulin-like growth factor binding protein-3 (IGFBP3) polymorphisms, on the growth response to rhGH therapy in GH-deficient (GHD) patients. Eighty-four severe GHD patients were genotyped for (CA)n IGF1, -202 A/C IGFBP3 and GHR-exon 3 polymorphisms. Multiple linear regressions were performed to estimate the effect of each genotype, after adjustment for other influential factors. We assessed the influence of genotypes on the first year growth velocity (1st y GV) (n=84) and adult height standard deviation score (SDS) adjusted for target-height SDS (AH-TH SDS) after rhGH therapy (n=37). Homozygosity for the IGF1 19CA repeat allele was negatively correlated with 1st y GV (P=0.03) and AH-TH SDS (P=0.002) in multiple linear regression analysis. In conjunction with clinical factors, IGF1 and IGFBP3 genotypes explain 29% of the 1st y GV variability, whereas IGF1 and GHR polymorphisms explain 59% of final height-target-height SDS variability. We conclude that homozygosity for IGF1 (CA)19 allele is associated with less favorable short- and long-term growth outcomes after rhGH treatment in patients with severe GHD. Furthermore, this polymorphism exhibits a non-additive interaction with -202 A/C IGFBP3 genotype on the 1st y GV and with GHR-exon 3 genotype on adult height.


Assuntos
Hormônio do Crescimento/deficiência , Hormônio do Crescimento/genética , Fator de Crescimento Insulin-Like I , Proteínas Recombinantes/administração & dosagem , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Criança , Pré-Escolar , Feminino , Genótipo , Hormônio do Crescimento/administração & dosagem , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Repetições de Microssatélites/genética , Farmacogenética , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Resultado do Tratamento
3.
Mol Endocrinol ; 12(3): 442-50, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9514160

RESUMO

In this report, the genomic DNA was examined from two siblings with gonadal LH resistance. A 46,XY pseudohermaphrodite presented with female external genitalia and his 46,XX sister exhibited menstrual irregularities (oligoamenorrhea) and infertility. Exons 1-11 of the LH receptor (LHR) gene were amplified by the PCR using different sets of intronic primers and were directly sequenced. Sequencing revealed that both individuals carried a deletion of nucleotides 1822-1827, resulting in the deletion of Leu-608 and Val-609 within the seventh transmembrane helix. This mutation was introduced into a recombinant human (h) LHR cDNA. Transfections of 293 cells with hLHR(wt) vs. hLHR(deltaL608,V609) revealed that very little of the mutant receptor was expressed at the cell surface. This was due to both a decrease in the total amount of receptor expressed as well as to an increased intracellular retention of the mutant receptor. In spite of the decreased cell surface expression of the mutant, sufficient amounts were present to allow for assessment of its functions. Equilibrium binding assays showed that the cell surface hLHR(deltaL608,V609) binds hCG with an affinity comparable to that of the wild-type receptor. However, the cells expressing the hLHR(deltaL608,V609) exhibit only a 1.5- to 2.4-fold stimulation of cAMP production in response to hCG. In contrast, cells expressing comparably low levels of hLHR(wt) responded to hCG with 11- to 30-fold increases of cAMP levels. Therefore, the testicular and ovarian unresponsiveness to LH in these patients appears to be due to a mutation of the hLHR gene in which Leu-608 and Val-609 are deleted. As a consequence, the majority of the mutant receptor is retained intracellularly. The small percentage of mutant receptor that is expressed at the cell surface binds hormone normally but is unable to activate Gs.


Assuntos
Mutação , Ovário/fisiopatologia , Receptores do LH/genética , Receptores do LH/metabolismo , Testículo/fisiopatologia , Adulto , Amenorreia/genética , Membrana Celular/metabolismo , Gonadotropina Coriônica/metabolismo , Gonadotropina Coriônica/farmacologia , AMP Cíclico/metabolismo , Transtornos do Desenvolvimento Sexual/genética , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Análise de Sequência de DNA , Deleção de Sequência , Transdução de Sinais , Transfecção
4.
Hum Mutat ; 14(4): 353, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10502786

RESUMO

Mutations of the androgen receptor gene causing androgen insensitivity syndrome in 46, XY individuals, result in phenotypes ranging from complete female to ambiguous genitalia to males with minor degrees of undervirilization. We studied two Brazilian brothers with partial androgen insensitivity syndrome. They were born with perineal hypospadias, bifid scrotum, small penis and cryptorchidism, and developed gynecomastia at puberty. Genomic DNA was extracted and denaturinggradient gel electrophoresis of exon 7 of the androgen receptor gene followed by sequence analysis revealed a new mutation, a C A transversion, altering codon 840 from arginine (CGT) to serine (AGT). R840 is located in the androgen binding domain, in a "hot spot" region, important for the formation and function of the hormone receptor-complex and within the region that is involved in androgen receptor dimerization. Replacement of arginine (basic) by serine (neutral and polar) is a nonconservative substitution. Three mutations in this residue (R840C, R840G nonconservative and R840H, conservative) were previously reported in patients with partial androgen insensitivity syndrome and when expressed "in vitro" lead to a subnormal transactivation of a reporter gene. We conclude that the novel R840 mutation in the androgen receptor is the cause of partial androgen insensitivity syndrome in this Brazilian family.


Assuntos
Síndrome de Resistência a Andrógenos/genética , Receptores Androgênicos/genética , Cromossomo X , Adolescente , Adulto , Feminino , Humanos , Masculino , Mutação Puntual
5.
J Clin Endocrinol Metab ; 86(9): 4068-71, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11549627

RESUMO

Primary adrenal insufficiency is a rare condition in pediatric age, and its association with precocious sexual development is very uncommon. We report a 2-yr-old Brazilian boy with DAX1 gene mutation whose first clinical manifestation was isosexual gonadotropin-independent precocious puberty. He presented with pubic hair, enlarged penis and testes, and advanced bone age. T levels were elevated, whereas basal and GnRH-stimulated LH levels were compatible with a prepubertal pattern. Chronic GnRH agonist therapy did not reduce T levels, supporting the diagnosis of gonadotropin-independent precocious puberty. Testotoxicosis was ruled out after normal sequencing of exon 11 of the LH receptor gene. At age 3 yr he developed clinical and hormonal features of severe primary adrenal insufficiency. The entire coding region of the DAX1 gene was analyzed through direct sequencing. A nucleotide G insertion between nucleotides 430 and 431 in exon 1, resulting in a novel frameshift mutation and a premature stop codon at position 71 of DAX-1, was identified. Surprisingly, steroid replacement therapy induced a clear decrease in testicular size and T levels to the prepubertal range. These findings suggest that chronic excessive ACTH levels resulting from adrenal insufficiency may stimulate Leydig cells and lead to gonadotropin-independent precocious puberty in some boys with DAX1 gene mutations.


Assuntos
Doenças das Glândulas Suprarrenais/congênito , Doenças das Glândulas Suprarrenais/genética , Hormônio Adrenocorticotrópico/fisiologia , Proteínas de Ligação a DNA/genética , Ligação Genética/genética , Puberdade Precoce/fisiopatologia , Receptores do Ácido Retinoico/genética , Proteínas Repressoras , Testículo/fisiopatologia , Fatores de Transcrição/genética , Doenças das Glândulas Suprarrenais/fisiopatologia , Pré-Escolar , Receptor Nuclear Órfão DAX-1 , DNA/análise , DNA/genética , Hormônios/sangue , Humanos , Masculino , Mutação , Puberdade Precoce/etiologia , Puberdade Precoce/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Testículo/patologia
6.
J Clin Endocrinol Metab ; 85(8): 2779-85, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10946881

RESUMO

Mutations in the pituitary-specific paired-like homeodomain transcription factor, PROP-1, result in combined pituitary hormone deficiency. We studied a Brazilian girl, offspring of first cousins, who presented with short stature and deficiencies of GH, TSH, PRL, LH, and FSH. Her cortisol response to hypoglycemia was determined at age 4.9, 10.7, and 14.1 yr and remained normal. Magnetic resonance imaging at the age of 9 yr revealed an anterior pituitary lobe of diminished height (3 mm; normal, 4.5 +/- 0.6), but radiography revealed a sella turcica volume above the normal mean. Direct sequencing of the PROP-1 gene revealed homozygosity for a novel 263T>C transition that results in the replacement of a highly conserved phenylalanine by serine at codon 88 (F88S). F88 constitutes the hydrophobic core of the first helix of the homeodomain of PROP-1, and the substitution by the polar residue serine is expected to alter the secondary structure and impair binding of the mutated PROP-1 to DNA target sequences. The F88S mutation (which corresponds to murine F85S) was introduced into the murine Prop-1 complementary DNA and its consequences on DNA binding and trans-activation were assessed in vitro. In contrast to wild-type Prop-1, the F88S mutant showed no significant DNA binding to a PRDQ9 Prop-1 response element in gel shift assays. Transcriptional activation of a luciferase reporter gene containing a PRDQ9 site upstream of a simian virus 40 promoter was reduced to approximately 34% compared with that of wild-type Prop-1 in transiently transfected TSA-201 human embryonic kidney cells. The F88S mutation further expands the repertoire of mutations in PROP-1.


Assuntos
Proteínas de Homeodomínio/genética , Hipopituitarismo/genética , Hormônios Hipofisários/deficiência , Mutação Puntual , Sequência de Aminoácidos , Substituição de Aminoácidos , Sequência de Bases , Consanguinidade , Sequência Conservada , Feminino , Humanos , Hipopituitarismo/tratamento farmacológico , Hipopituitarismo/fisiopatologia , Lactente , Masculino , Fenilalanina , Hipófise/diagnóstico por imagem , Radiografia , Serina
7.
J Clin Endocrinol Metab ; 84(2): 802-4, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10022457

RESUMO

In genetic males, mutation of the 17beta-hydroxysteroid dehydrogenase 3 (17HSD3)gene that is normally expressed in the testes impairs testosterone formation and causes development of male pseudohermaphroditism. We have ascertained seven women who are sisters of men with 17HSD3 deficiency and who are either homozygotes or compound heterozygotes for the same mutations as their affected brothers. Our findings confirm the concept that women with such mutations are asymptomatic.


Assuntos
17-Hidroxiesteroide Desidrogenases/deficiência , Isoenzimas/deficiência , 17-Hidroxiesteroide Desidrogenases/genética , Adulto , Transtornos do Desenvolvimento Sexual/genética , Feminino , Heterozigoto , Homozigoto , Humanos , Infertilidade Feminina/genética , Isoenzimas/genética , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem
8.
J Clin Endocrinol Metab ; 86(6): 2680-6, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11397871

RESUMO

Several point mutations in the GnRH receptor gene have been described in an autosomal recessive form of congenital isolated hypogonadotropic hypogonadism (HH). We investigated 17 Brazilian patients (10 males and 7 females) from 14 different families, with HH and normal olfaction. The diagnosis of HH was based on absent or incomplete sexual development after 17 yr of age associated with low or normal levels of LH in both sexes and low levels of testosterone in males and of estradiol in females. All patients presented with a normal sense of smell in an olfactory specific test. The coding region of the GnRH receptor gene was amplified by PCR and directly sequenced. A novel missense mutation, Arg(139)His, located in the conserved DRS motif at the junction of the third transmembrane and the second intracellular loop of the GnRH receptor was identified in the homozygous state in one female with complete HH. The Arg(139)His mutation completely eliminated detectable GnRH-binding activity and prevented GnRH-induced stimulation of inositol phosphate accumulation in vitro. In another family, a new compound heterozygous mutation (Asn(10)Lys and Gln(106)Arg) was identified in four siblings (two males and two females) with partial HH. The Gln(106)Arg mutation, located in the first extracellular loop, has been previously described, and in vitro analysis indicated that the mutant receptor was able to bind GnRH, but with a reduced affinity. The Asn(10)Lys mutation in the extracellular amino-terminal domain of the receptor also reduced the affinity for GnRH in vitro. In this family we also identified a previously described silent polymorphism at amino acid residue 151 in the second intracellular loop that segregated with the two inactivating mutations of the GnRH receptor. This polymorphism was also found in two unrelated patients with sporadic HH without GnRH receptor loss of function mutations. No mutations were identified in the remaining cases. A good correlation between genotype and phenotype was found in our patients. The woman, who is homozygous for the completely inactivating Arg(139)His mutation, has complete HH with undetectable serum basal LH and FSH levels that failed to respond to GnRH stimulation. In addition, the affected patients who are compound heterozygotes for the Asn(10)Lys/Gln(106)Arg mutations, have partial HH with low serum basal LH levels that were responsive to GnRH stimulation. No clinical or hormonal differences were found between HH patients with and without mutations in the GnRH receptor gene, indicating that these data do not contribute to the identification of HH patients with GnRH receptor mutations. In conclusion, we report the first naturally occurring mutation within the conserved DRS motif of the GnRH receptor in a female with complete HH and a novel compound heterozygous mutation (Asn(10)Lys and Gln(106)Arg) in a family with partial HH, increasing the repertoire of the inactivating mutations of the GnRH receptor.


Assuntos
Hipogonadismo/genética , Hipogonadismo/fisiopatologia , Mutação/genética , Receptores LHRH/genética , Olfato/fisiologia , Adolescente , Adulto , Animais , Brasil , Células COS , Membrana Celular/metabolismo , Feminino , Heterozigoto , Homozigoto , Humanos , Fosfatos de Inositol/metabolismo , Masculino , Linhagem , Receptores LHRH/metabolismo , Valores de Referência
9.
J Clin Endocrinol Metab ; 85(3): 1211-4, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10720064

RESUMO

Ovarian steroid cell tumors are rare neoplasms composed of typical steroid hormone-secreting cells. Most ovarian steroid cell tumors, however, cannot be appropriately classified on a morphological basis, because the neoplastic cells closely resemble adrenal cortical cells. Nevertheless, the true adrenal origin of such tumors has been difficult to demonstrate. Here we report a 3-yr-old girl with isosexual pseudoprecocious puberty due to an ovarian steroid tumor whose adrenal cell origin was determined by the presence of messenger ribonucleic acid (mRNA) of adrenal-specific steroidogenic P450 enzymes (P450c11 and P450c21) and ACTH receptor (ACTHR). Her height was +2.3 SD, and she had Tanner stage III breast development, Tanner stage II pubic hair, and a normal clitoris. Bone age was 5 yr. Basal gonadotropin levels were undetectable (<0.6 U/L for LH and <1.0 U/L for FSH) and remained undetectable after stimulation with 100 microg GnRH, i.v. Basal serum testosterone and 17-hydroxyprogesterone levels were slightly elevated, whereas basal serum androstenedione, estradiol, and dehydroepiandrosterone sulfate levels were clearly elevated. Pelvic ultrasound disclosed an enlarged uterus and an adnexal multicystic mass in the right ovary, and pathological studies disclosed an ovarian steroid cell tumor. To establish the cellular origin of the tumor we determined the presence of mRNA for P450c11, P450c21, and ACTHR in tumor tissue and normal adrenal and ovarian tissue. Detection of ACTHR, P450c21, and P450c11 mRNAs isoforms was achieved in tumoral and adrenal control tissue, but not in the ovary control tissue. The RT-PCR products of P450c11 from adrenal control tissue were composed by both BglI-sensitive and -resistant complementary DNAs, indicating the presence of both P450c11AS and P450c11beta, whereas RT-PCR product from the tumor was resistant to BglI digestion, indicating only the presence of P450c11beta. We conclude that the histological origin of so-called adrenal rest tumor could be reliably determined by assessing the expression of specific genes in the tumor as P450c11beta and P450c21. The use ofthese molecular tools will allow a more precise classification of an important subset of the ovarian steroid cell tumors and can help to identify ectopic adrenal tissue in ovary and testis.


Assuntos
Glândulas Suprarrenais/metabolismo , Neoplasias Ovarianas/patologia , Puberdade Precoce/etiologia , Receptores da Corticotropina/metabolismo , Esteroides/biossíntese , Glândulas Suprarrenais/enzimologia , Pré-Escolar , Feminino , Hormônios Esteroides Gonadais/sangue , Humanos , Neoplasias Ovarianas/complicações , Neoplasias Ovarianas/enzimologia , Puberdade Precoce/enzimologia , RNA Mensageiro/análise , RNA Neoplásico/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
J Clin Endocrinol Metab ; 80(8): 2490-4, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7629248

RESUMO

Familial male-limited precocious puberty (FMPP) is an autosomal dominant gonadotropin-independent disorder. Affected males generally develop signs of precocious puberty in early childhood. They typically show Leydig cell hyperplasia and increased testosterone production typical for their age, whereas circulating LH concentrations remain prepubertal. Several dominant point mutations of the LH receptor gene were identified in pedigrees with familial male-limited precocious puberty and were shown to cosegregate with the disease. Here we report a novel heterozygote point mutation in the LH receptor gene of a Brazilian boy with gonadotropin-independent precocious puberty. This mutation substitutes alanine 568 with valine at the carboxyterminus of the third cytosolic loop of the LH receptor. The unoccupied mutant receptors confer constitutive activation of adenyl cyclase activity when expressed in COS-7 cells, resulting in 4-fold higher cAMP concentrations over baseline compared with cells expressing an equivalent number of wild-type receptors. The affinity of the mutant receptors to 125I-labeled human LH was not altered compared with the wild type. Mutations of the homologue alanine residue in the alpha 1-adrenergic (in vitro), FSH (in vitro), and TSH (naturally occurring) receptors also result in constitutive adenyl cyclase activation, suggesting that this alanine residue is crucial for signal transduction and a potential site for upregulatory/oncogenic mutations in G-protein coupled receptors.


Assuntos
Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Mutação Puntual , Puberdade Precoce/genética , Receptores do LH/genética , Alanina , Sequência de Aminoácidos , Androgênios/sangue , Animais , Sequência de Bases , Linhagem Celular , Pré-Escolar , Chlorocebus aethiops , AMP Cíclico/metabolismo , DNA/genética , Primers do DNA , Hormônio Foliculoestimulante/metabolismo , Triagem de Portadores Genéticos , Hormônio Liberador de Gonadotropina/farmacologia , Humanos , Hormônio Luteinizante/metabolismo , Hormônio Luteinizante/farmacologia , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Conformação Proteica , Puberdade Precoce/sangue , Receptores do LH/biossíntese , Receptores do LH/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Valores de Referência , Transfecção , Valina
11.
J Clin Endocrinol Metab ; 84(3): 942-5, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10084575

RESUMO

Genomic DNA from 18 patients with combined pituitary hormone deficiency was screened for 2-bp deletion (A301,G302) in PROP1 gene by BcgI restriction endonuclease analysis of PCR-amplified exon 2 gene fragments. Two unrelated female patients were homozygous for this 2-bp deletion. Patient 1 presented at 8.8 yr with severe short stature (-2.9 SD score), slightly enlarged sella turcica at x-rays, and diffusely enlarged pituitary gland (height, 8 mm vs. 4.5 +/- 0.6 mm in matched controls) with hyperintense enhanced signal at T1 weighted image at coronal and sagittal views at magnetic resonance imaging (MRI). MRI repeated at age 15 yr revealed a marked reduction of pituitary height (2 mm vs. 5.3 +/- 0.8 mm in matched controls). Patient 2 presented at 27 yr with short stature (-5.5 SD score) without pubertal development, normal sella turcica, and a pituitary gland of reduced size (height, 5 mm vs. 6.1 +/- 0.3 mm in matched controls) of normal intensity at MRI. Both patients had normal pituitary stalk and normally located neurohypophysis. Hormonal features were characterized by GH, TSH, PRL, LH, and FSH deficiencies. Patient 1 had normal cortisol secretion at 8.8 yr, and at 16.6 yr had developed partial cortisol deficiency, whereas patient 2 maintained normal cortisol secretion at 28.4 yr. We conclude that 1) a large sella turcica and an enlarged pituitary anterior lobe with hyperintense enhanced signal at T1 at MRI can be suggestive of PROP1 deficiency; 2) pituitary morphology can change during follow-up of patients with PROP1 gene mutation; and 3) hormonal deficiencies could include the adrenal axis.


Assuntos
Deleção de Genes , Proteínas de Homeodomínio/genética , Hormônios/sangue , Hipófise/patologia , Hormônios Hipofisários/deficiência , Fatores de Transcrição/genética , Criança , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Reação em Cadeia da Polimerase , Radiografia , Crânio/diagnóstico por imagem
12.
J Clin Endocrinol Metab ; 83(7): 2435-40, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9661624

RESUMO

Several constitutively activating mutations have been demonstrated in the sixth transmembrane helix of the human LH receptor (hLHR) in boys with gonadotropin-independent precocious puberty. In the current study, we examined two unrelated Brazilian boys with gonadotropin-independent precocious puberty caused by two different heterozygous activating mutations of the hLHR. Direct sequencing of the entire exon 11 of the hLHR revealed a heterozygous substitution of T for G at nucleotide 1370, that converts Leu 457 to Arg in the third transmembrane helix of the hLHR in one affected boy. His biological parents had a normal hLHR gene sequence, establishing the sporadic nature of this novel Leu457Arg mutation. Human embryonic 293 cells expressing hLHR mutant (L457R) or hLHR wild-type bound CG with high affinity. However, cells expressing hLHR(L457R) exhibited significantly higher basal levels of cAMP (7- to 14-fold) than cells expressing the wild-type receptor, indicating constitutive activation of hLHR(L457R). Basal levels of cAMP in hLHR(L457R)-expressing cells were, nonetheless, not as great as the levels of cAMP produced by hLHR wild-type-expressing cells incubated with a saturating concentration of CG. Furthermore, cells expressing hLHR(L457R) were unresponsive to further stimulation by CG. This finding was confirmed in the patient by lack of an increase in serum testosterone after CG stimulation. These results suggest that the conformation of hLHR(L457R) mutant represents a different activated receptor state (R*) than the agonist-occupied wild-type receptor. We also identified the previously described Ala568Val mutation in the third intracellular loop of the LHR in the other affected African-Brazilian boy and his normal prepubertal sister, suggesting the inherited form of precocious puberty in this boy. We conclude that the third transmembrane helix is a potential area for activating mutations of the hLHR that cause male precocious puberty.


Assuntos
Gonadotropinas Hipofisárias/metabolismo , Heterozigoto , Mutação Puntual , Estrutura Secundária de Proteína , Puberdade Precoce/genética , Receptores do LH/genética , Sequência de Aminoácidos , Brasil , Membrana Celular/fisiologia , Criança , Pré-Escolar , Humanos , Masculino , Dados de Sequência Molecular
13.
J Clin Endocrinol Metab ; 83(9): 3346-9, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9745452

RESUMO

Combined pituitary hormone deficiency (CPHD) has an incidence of approximately 1 in 8000 births. Although the proportion of familial CPHD cases is unknown, about 10% have an affected first degree relative. We have recently reported three mutations in the PROP1 gene that cause CPHD in human subjects. We report here the frequency of one of these mutations, a 301-302delAG deletion in exon 2 of PROP1, in 10 independently ascertained CPHD kindreds and 21 sporadic cases of CPHD from 8 different countries. Our results show that 55% (11 of 20) of PROP1 alleles have the 301-302delAG deletion in familial CPHD cases. Interestingly, although only 12% (5 of 42) of the PROP1 alleles of our 21 sporadic cases were 301-302delAG, the frequency of this allele (in 20 of 21 of the sporadic subjects given TRH stimulation tests) was 50% (3 of 6) and 0% (0 of 34) in the CPHD cases with pituitary and hypothalamic defects, respectively. Using whole genome radiation hybrid analysis, we localized the PROP1 gene to the distal end of chromosome 5q and identified a tightly linked polymorphic marker, D5S408, which can be used in segregation studies. Analysis of this marker in affected subjects with the 301-302delAG deletion suggests that rather than being inherited from a common founder, the 301-302delAG may be a recurring mutation.


Assuntos
Composição de Bases , Deleção de Genes , Proteínas de Homeodomínio/genética , Hormônios Hipofisários/deficiência , Fatores de Transcrição/genética , Alelos , Mapeamento Cromossômico , Cromossomos Humanos Par 5 , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Éxons , Genótipo , Humanos , Repetições de Microssatélites , Linhagem , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
14.
J Clin Endocrinol Metab ; 83(12): 4416-9, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9851787

RESUMO

The aim of our study was to determine, by allele-specific PCR, the frequency of point mutations in 130 Brazilian patients with the classical and nonclassical forms of 21-hydroxylase deficiency and to correlate genotype with phenotype. The most frequent mutations were 12 splice (41.8% in salt wasting), I172N (32.6% in simple virilizing), and V281L (40.2% in late onset form). The frequency of the 9 most common point mutations was similar to that reported for other countries, except for Del 8 nt and Cluster, which were less frequent in the classical form. Rarer mutations such as P453S, G291S, I7 splice, W405X, R483P, and R483-->frameshift were rarely found or were absent. The 93 fully genotyped patients were classified into 3 mutation groups, based on the degree of enzymatic activity (group A, <2%; group B, approximately 2%, and group C, >18%). In group A, 62% of the cases presented the salt wasting form; in group B, 96% the simple virilizing form; and in group C, 88% the late onset form. We diagnosed 80% of the affected alleles after screening for large rearrangements and 15 point mutations. The absence of previously described mutations in 20% of the affected alleles suggests the presence of new mutations in our population.


Assuntos
Hiperplasia Suprarrenal Congênita , Hiperplasia Suprarrenal Congênita/genética , Alelos , Brasil , Estudos de Coortes , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Fenótipo , Mutação Puntual/genética , Esteroide 21-Hidroxilase/genética
15.
J Clin Endocrinol Metab ; 85(12): 4799-805, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11134146

RESUMO

Naturally occurring activating mutations in the human LH receptor (hLHR) gene are the cause of sporadic or familial male gonadotropin-independent precocious puberty. We have previously reported three different activating mutations of the hLHR gene in four unrelated Brazilian boys with male-limited precocious puberty. In the current study, we examined three other Brazilian boys, two brothers and one unrelated boy, with gonadotropin-independent precocious puberty. Direct sequencing of the entire exon 11 of the hLHR gene in the two brothers revealed a heterozygous substitution of T for C at nucleotide 1103, resulting in the substitution of leucine at position 368 by proline in the first transmembrane helix. Their mother carried the same mutation, establishing the familial nature of this mutation. Human embryonic 293 cells expressing hLHR(L368P) bound hCG with the same high affinity as cells expressing the wild-type hLHR. Cells expressing the novel L368P mutation displayed up to a 12-fold increase in basal cAMP production compared with cells expressing the same number of cell surface wild-type hLHR, indicating constitutive activation of the mutant receptor. In addition, the cAMP levels in cells expressing the hLHR mutant were further augmented by hCG. Molecular dynamics simulations suggest that substitution of L368 of the hLHR by proline results in lack of a salt bridge interaction between D405 and R464 (distance 9. 0 A vs. 4.7 A in wild-type hLHR) as well as by the opening of a crevice between the second and third intracellular loops, which may allow G proteins greater accessibility. These structural features were shared by other activating mutants of the hLHR. Sequencing of exon 11 of the hLHR gene of the unrelated boy revealed that he carried a homozygous nucleotide substitution causing an A568V mutation in the third cytoplasmic loop of the receptor. This mutation was previously found in two unrelated Brazilian boys, but in heterozygous state. Clinical and hormonal data of the patient with the homozygous A568V were not different from those individuals with the Ala568Val mutation in a heterozygous state. Furthermore, the phenotype caused by dominant activating mutations of the hLHR gene are not altered when both alleles carry a mutant sequence. Our studies show that the A568V is the most frequent cause of male-limited precocious puberty in Brazilian boys. Lastly, the identification of a novel activating L368P mutation in the first transmembrane helix of two Brazilian boys with familial male-limited precocious puberty provides further insights into the mechanism of activation of the hLHR.


Assuntos
Mutação/genética , Puberdade Precoce/genética , Receptores do LH/genética , Substituição de Aminoácidos , Membrana Celular/fisiologia , Criança , Pré-Escolar , Gonadotropina Coriônica/metabolismo , AMP Cíclico/metabolismo , DNA/análise , DNA/genética , Humanos , Masculino , Modelos Moleculares , Mutagênese , Puberdade Precoce/patologia , Transfecção
16.
J Clin Endocrinol Metab ; 84(8): 2870-2, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10443693

RESUMO

A previous screening of 17 mutations in 130 Brazilian patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency did not identify mutations in 20% of the alleles. To diagnose these alleles we sequenced the entire CYP21 gene of one Mulatto patient with the simple virilizing form, who had only the R356W mutation in a heterozygous state. We identified a heterozygous G-A transition in codon 424. This mutation leads to a substitution of glycine by serine in a conserved region where glycine is conserved in at least 4 species. This novel mutation eliminates 1 of the restriction sites of the BanI enzyme, which made its screening possible for the whole series. The G424S mutation was found in a compound heterozygous state in 5 families; 4 presented the simple virilizing form, and 1 presented the nonclassical form. Interestingly, 3 of 5 families have a Mulatto origin. This mutation was not identified in 118 CYP21 alleles of normal individuals, ruling out the possibility of a polymorphism, or in 80 pseudogenes, indicating a casual mutagenic event and not a microconversion event. All patients with the G424S mutation presented CYP21P and C4A gene deletions and human leukocyte antigen DR17 on the same haplotype, suggesting a linkage disequilibrium and a probable founder effect. Search for the G424S mutation in other populations will reveal whether it is restricted to the Brazilian patients or if it has a wider ethnic distribution.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Mutação de Sentido Incorreto , Esteroide 21-Hidroxilase/genética , Feminino , Humanos , Desequilíbrio de Ligação , Masculino , Reação em Cadeia da Polimerase
17.
J Clin Endocrinol Metab ; 84(10): 3539-44, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10522992

RESUMO

To establish normative data and determine the value of fluorometric AutoDELFIA assays (Wallac Oy) in the investigation of precocious puberty, we determined serum levels of LH, FSH, testosterone, and estradiol under basal and GnRH-stimulated conditions in 277 normal subjects at various pubertal stages and in 77 patients with precocious puberty. A substantial overlap was observed in basal and GnRH-stimulated gonadotropin levels in normal individuals of both sexes with pubertal Tanner stages 1 and 2. The 95th percentile of the normal prepubertal population was the cut-off limit between prepubertal and pubertal levels. These limits were 0.6 IU/L in both sexes for basal LH, 9.6 IU/L in boys and 6.9 IU/L in girls for peak LH after GnRH stimulation, 19 ng/dL in boys for basal testosterone, and 13.6 pg/mL in girls for basal estradiol. Basal and peak LH exceeding these limits were considered positive tests for the diagnosis of gonadotropin-dependent precocious puberty. According to these criteria, the sensitivities of basal and peak LH for the latter diagnosis were 71.4% and 100% in boys, and 62.7% and 92.2% in girls. The specificity and positive predicted value were 100% in both sexes for basal and peak LH levels. The negative predicted values for basal and peak LH were 62.5% and 100% in boys, and 40.6% and 76.5% in girls. Basal and GnRH-stimulated FSH levels overlapped among the various pubertal stages in normal subjects and were, in general, not helpful in the differential diagnosis of precocious puberty. In conclusion, basal LH levels were sufficient to establish the diagnosis of gonadotropin-dependent precocious puberty in 71.4% of boys and 62.7% of girls. In the remaining patients, a GnRH stimulation test was still necessary to confirm this diagnosis. Finally, suppressed LH and FSH levels after GnRH stimulation indicate gonadotropin-independent sexual steroid production.


Assuntos
Fluorometria/normas , Puberdade Precoce/diagnóstico , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Hormônio Liberador de Gonadotropina , Gonadotropinas/sangue , Humanos , Masculino , Puberdade Precoce/sangue , Valores de Referência , Esteroides/sangue
18.
Medicine (Baltimore) ; 75(2): 64-76, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8606628

RESUMO

Sixteen subjects (from 10 Brazilian families) with male pseudohermaphroditism due to steroid 5alpha-reductase 2 deficiency have been evaluated in 1 clinic. The diagnoses were made on the basis of normal plasma testosterone values, normal or low plasma dihydrotestosterone levels and high testosterone/dihydrotestosterone ratios in the basal state in postpubertal subjects or after treatment with either human chorionic gonadotropin or testosterone in prepubertal subjects. The analysis of the ratios of etiocholanolone to androsterone in urine confirmed the diagnosis in all subjects who were tested, and the molecular basis of the underlying mutations was established in 9 of the families. Fourteen of the individuals were evaluated by the same psychologist. All subjects but 1 were given a female sex assignment at birth. Three of the subjects (1 the sibling of an individual who has undergone female to male social behavior) maintain a female social sex; they have been gonadectomized and treated with exogenous estrogens. Ten of 13 subjects of postpubertal age underwent a change of social sex from female to male, had surgical correction of the hypospadias, and were treated with high-dose testosterone esters by parenteral injection and subsequently with dihydrotestosterone cream. These regimens brought serum dihydrotestosterone levels to the normal male range (or above) but resulted only in limited growth of the prostate and penis and, in some, increase in body and facial hair and enhancement of libido and sexual performance. Treatment of the prepubertal boys with testosterone and/or dihydrotestosterone resulted in a doubling of penis size.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/deficiência , Transtornos do Desenvolvimento Sexual/enzimologia , Adolescente , Adulto , Criança , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/psicologia , Transtornos do Desenvolvimento Sexual/terapia , Identidade de Gênero , Humanos , Masculino , Testosterona/sangue , Testosterona/uso terapêutico , Resultado do Tratamento
19.
Medicine (Baltimore) ; 79(5): 299-309, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11039078

RESUMO

Ten male pseudohermaphrodites with 17 beta-hydroxysteroid dehydrogenase 3 (17 beta-HSD3) deficiency were evaluated in 1 clinic with an average follow-up of 10.1 years. The diagnoses were made by demonstrating low to normal serum testosterone levels, high androstenedione levels, and high ratios of serum androstenedione to testosterone in the basal state or after treatment with human chorionic gonadotropin. The molecular features of the underlying mutations were identified in all 7 families. Two additional males in the same families are believed to be affected on the basis of history obtained from family members. All of the 46,XY individuals in these families were registered at birth and raised as females (despite the presence of ambiguous genitalia in all or most), and all virilized after the time of expected puberty due to a rise in serum testosterone to or toward the normal male range. The age at diagnosis varied from 4 to 37 years. Ten individuals were studied by the same psychologist, and change of gender role (social sex) from female to male occurred in 3 subjects and in the 2 presumed affected subjects not studied. The individual with the highest serum testosterone level maintained female sexual identity, and in 2 families some of the affected males changed gender role and others did not. Thus, while androgen action plays a role in the process, additional undefined psychological, social, and/or biologic factors must be determinants of gender identity/role behavior. Management of the 7 individuals who chose to maintain female sex roles included castration, clitoroplasty, vaginal enlargement procedures when appropriate, treatment of hirsutism, cricoid cartilage reduction, and estrogen replacement. Three of the 7 are married (2 twice), 1 is involved in a long-term heterosexual relationship, 1 is engaged to be married, and the other 2 are not married and not believed to be sexually active. The 3 subjects who changed gender role behavior to male underwent hypospadias repair, and 1 was given supplemental testosterone therapy. One of these men is divorced, and the other 2 (aged 29 and 35 years) are unmarried. The diagnosis in 8 of these subjects was made after the time of expected puberty; it is unclear whether the functional and social outcomes would have been different if the diagnosis had been made and therapy begun earlier in life.


Assuntos
17-Hidroxiesteroide Desidrogenases/deficiência , Transtornos do Desenvolvimento Sexual/diagnóstico , Adolescente , Adulto , Androstenodiona/sangue , Criança , Transtornos do Desenvolvimento Sexual/enzimologia , Transtornos do Desenvolvimento Sexual/psicologia , Transtornos do Desenvolvimento Sexual/terapia , Hormônio Foliculoestimulante/sangue , Seguimentos , Humanos , Hormônio Luteinizante/sangue , Masculino , Testosterona/sangue
20.
J Mol Endocrinol ; 12(1): 119-22, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8185809

RESUMO

A mutation (A82T) is described in the coding sequence of the gene for 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) type II that is associated with variable clinical consequences. Four homozygotes are described, all of which showed elevated levels of delta 5 steroids consistent with 3 beta-HSD deficiency. Two males from a consanguineous family were found to be homozygous for A82T and were affected with pseudohermaphroditism. They differed in their degree of mild salt loss. In the same family a female was found to be homozygous for A82T, but was clinically normal and had no history of premature pubarche or of abnormal menstrual cycles. However, in an apparently unrelated family, the A82T mutation was found in a female affected with premature pubarche. This is the first report of a proven mutation in 3 beta-HSD type II associated with premature pubarche.


Assuntos
3-Hidroxiesteroide Desidrogenases/genética , Transtornos do Desenvolvimento Sexual/genética , Mutação , Puberdade Precoce/genética , 3-Hidroxiesteroide Desidrogenases/metabolismo , Adolescente , Adulto , Criança , Pré-Escolar , Transtornos do Desenvolvimento Sexual/enzimologia , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Puberdade Precoce/enzimologia
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