Classes and predictors of reversal in male patients with congenital hypogonadotropic hypogonadism: a cross-sectional study of six international referral centres.

BACKGROUND: Although some male patients with congenital hypogonadotropic hypogonadism (CHH) undergo spontaneous reversal following treatment, predictors of reversal remain elusive. We aimed to assemble the largest cohort of male patients with CHH reversal to date and identify distinct classes of reversal. METHODS: This multicentre cross-sectional study was conducted in six international CHH referral centres in Brazil, Finland, France, Italy, the UK, and the USA. Adult men with CHH (ie, absent or incomplete spontaneous puberty by age 18 years, low serum testosterone concentrations, and no identifiable cause of hypothalamic-pituitary-gonadal [HPG] axis dysfunction) were eligible for inclusion. CHH reversal was defined as spontaneous recovery of HPG axis function off treatment. Centres provided common data elements on patient phenotype, clinical assessment, and genetics using a structured, harmonised data collection form developed by COST Action BM1105. Latent class mixture modelling (LCMM) was applied to establish whether at least two distinct classes of reversal could be identified and differentially predicted, and results were compared with a cohort of patients without CHH reversal to identify potential predictors of reversal. The primary outcome was the presence of at least two distinct classes of reversal. FINDINGS: A total of 87 male patients with CHH reversal and 108 without CHH reversal were included in the analyses. LCMM identified two distinct reversal classes (75 [86%] in class 1 and 12 [14%] in class 2) on the basis of mean testicular volume, micropenis, and serum follicle-stimulating hormone (FSH) concentration. Classification probabilities were robust (0·998 for class 1 and 0·838 for class 2) and modelling uncertainty was low (entropy 0·90). Compared with class 1, patients in class 2 had significantly larger testicular volume (p<0·0001), no micropenis, and higher serum FSH concentrations (p=0·041), consistent with the Pasqualini syndrome (fertile eunuch) subtype of CHH. Patients without CHH reversal were more likely to have anosmia (p=0·016), cryptorchidism (p=0·0012), complete absence of puberty (testicular volume <4 cm³; p=0·0016), and two or more rare genetic variants (ie, oligogenicity; p=0·0001). Among patients who underwent genetic testing, no patients (of 75) with CHH reversal had a rare pathogenic ANOS1 variant compared with ten (11%) of 95 patients without CHH reversal. Individuals with CHH reversal had a significantly higher rate of rare variants in GNRHR than did those without reversal (nine [12%] of 75 vs three [3%] of 95; p=0·025). INTERPRETATION: Applying LCMM to a large cohort of male patients with CHH reversal uncovered two distinct classes of reversal. Genetic investigation combined with careful clinical phenotyping could help surveillance of reversal after withdrawing treatment, representing the first tailored management approach for male patients with this rare endocrine disorder. FUNDING: National Institutes of Health National Center for Advancing Translational Sciences; Ministry of Health, Rome, Italy; Ministry of University, Rome, Italy; National Institutes of Health Eunice Kennedy Shriver National Institute of Child Health and Human Development; and the Josiah Macy Jr Foundation. TRANSLATION: For the Italian translation of the abstract see Supplementary Materials section.

Association between KISS1 rs5780218 promoter polymorphism and onset of growth hormone secreting pituitary adenoma.

OBJECTIVES: This study analyzed the KISS1 c.-145delA (rs5780218) promoter polymorphism in a cohort of patients with growth hormone secreting pituitary adenoma (somatotropinoma) and controls, to investigate its role in the incidence of acromegaly and to assess patient/tumor characteristics. Material and methods rs5780218 allelic and genotypic distributions were compared between 49 somatotropinoma patients and 167 healthy controls. rs5780218 was also assessed in relation to patient characteristics and tumor aggressiveness, as characterized by tumor invasion and resistance to conventional therapy. The relationship between KISS1 mRNA expression and the rs5780218 genotype was also assessed in available pituitary tumor samples. RESULTS: The homozygous -/- variant genotype was associated with high rates of somatotropinoma (P<0.01), but not with tumor invasiveness, patient characteristics or hormonal remission. KISS1 mRNA expression was much lower in somatotropinomas carrying the deleted allele than in homozygous wild type AA. CONCLUSIONS: In this pilot study, the rs5780218 promoter polymorphism was evaluated in pituitary adenoma, and showed a possible association with the incidence of somatotropinoma but not with tumor progression.

Factors determining normal adult height in girls with gonadotropin-dependent precocious puberty treated with depot gonadotropin-releasing hormone analogs.

CONTEXT: Several factors can affect adult height (AH) of patients with gonadotropin-dependent precocious puberty (GDPP) treated with depot GnRH analogs. OBJECTIVE: Our objective was to determine factors influencing AH in patients with GDPP treated with depot GnRH analogs. PATIENTS: A total of 54 patients (45 girls) with GDPP treated with depot GnRH analog who reached AH was included in the study. DESIGN: Univariate and multivariate analyses of the factors potentially associated with AH were performed in all girls with GDPP. In addition, clinical features of the girls who attained target height (TH) range were compared with those who did not. Predicted height using Bayley and Pinneau tables was compared with attained AH. RESULTS: In girls the mean AH was 155.3 +/- 6.9 cm (-1.2 +/- 1 sd) with TH range achieved by 81% of this group. Multiple regression analysis revealed that the interval between chronological age at onset of puberty and at the start of GnRH analog therapy, height sd scores (SDSs) at the start and end of therapy, and TH explained 74% of AH variance. The predicted height at interruption of GnRH therapy, obtained from Bayley and Pinneau tables for average bone age, was more accurate than for advanced bone age in both sexes. In boys the mean AH was 170.6 +/- 9.2 cm (-1 +/- 1.3 SDS), whereas TH was achieved by 89% of this group. CONCLUSIONS: The major factors determining normal AH in girls with GDPP treated with depot GnRH analogs were shorter interval between the onset of puberty and start of therapy, higher height SDS at the start and end of therapy, and TH. Therefore, prompt depot GnRH analog therapy in properly selected patients with GDPP is critical to obtain normal AH.

Hypogonadotropic hypogonadism.

Hypogonadotropic hypogonadism is characterized by failure of gonadal function secondary to deficient gonadotropin secretion, resulting from either a pituitary or hypothalamic defect, and is commonly seen in association with structural lesions or functional defects affecting this region. Although the genetic basis for idiopathic hypogonadotropic hypogonadism is largely unknown, mutations in several genes involved in the hypothalamo-pituitary-gonadal axis development and function have recently been implicated in the pathogenesis of this condition. Genes currently recognized to be involved include KAL-1 (associated with X-linked Kallmann Syndrome), gonadotropin-releasing hormone (GnRH) receptor, gonadotropins, pituitary transcription factors (HESX1, LHX3, and PROP-1), orphan nuclear receptors (DAX-1, associated with X-linked adrenal hypoplasia congenital, and SF-1), and three genes also associated with obesity (leptin, leptin receptor, and prohormone convertase 1 [ PC1]). Study of these mutations provides an important contribution in the understanding of the different stages of the reproductive axis development and physiology. Treatment options currently available for puberty induction, maintenance replacement therapy, and fertility induction are considered here. Gametogenesis can be induced with either exogenous gonadotropin or pulsatile GnRH therapy, depending on the etiology.

Mutational analysis of KISS1 and KISS1R in idiopathic central precocious puberty.

AIM: The genetic background of idiopathic central precocious puberty (ICPP) is not well understood. The genetic activation of pubertal onset is thought to arise from the effect of multiple genes. Familial ICPP has been reported suggesting the existence of monogenic causes of ICPP. Kisspeptin and its receptor are found to be involved in gonadotropin-releasing hormone (GnRH) secretion and puberty onset. Mutations in their genes, KISS1 and KISSR, have been suggested to be causative for ICPP. METHODS: ICPP was defined by pubertal onset before 8 years of age in girls, and a pubertal luteinizing hormone (LH) response to GnRH testing. Twenty-eight girls with ICPP were included in the study [age at diagnosis was 5.72±2.59, with a mean bone age advancement of 1.4 years (-0.1 to 2.8). Height at onset of therapy in SD score was 0.90±1.48 for age]. Luteinizing hormone-releasing hormone test was performed in all subjects, and all of them had a pubertal response (LH 20.35±32.37 mIU/mL; FSH 23.32±15.72 mIU/mL). The coding regions of KISS1 and KISS1R were sequenced. RESULTS: No rare variants were detected in KISS1 or KISS1R in the 28 subjects with ICPP. CONCLUSIONS: We confirmed that mutations in KISS1 and KISS1R are not a common cause for ICPP.

Role of gonadotropin-releasing hormone receptor mutations in patients with a wide spectrum of pubertal delay.

OBJECTIVE: To analyze the GNRHR in patients with normosmic isolated hypogonadotropic hypogonadism (IHH) and constitutional delay of growth and puberty (CDGP). DESIGN: Molecular analysis and in vitro experiments correlated with phenotype. SETTING: Academic medical center. PATIENT(S): A total of 110 individuals with normosmic IHH (74 male patients) and 50 with CDGP. INTERVENTION(S): GNRHR coding region was amplified and sequenced. MAIN OUTCOME MEASURE(S): Novel variants were submitted to in vitro analysis. Frequency of mutations and genotype-phenotype correlation were analyzed. Microsatellite markers flanking GNRHR were examined in patients carrying the same mutation to investigate a possible founder effect. RESULT(S): Eleven IHH patients (10%) carried biallelic GNRHR mutations. In vitro analysis of novel variants (p.Y283H and p.V134G) demonstrated complete inactivation. The founder effect study revealed that Brazilian patients carrying the p.R139H mutation shared the same haplotype. Phenotypic spectrum in patients with GNRHR mutations varied from complete GnRH deficiency to partial and reversible IHH, with a relatively good genotype-phenotype correlation. One boy with CDGP was heterozygous for the p.Q106R variant, which was not considered to be pathogenic. CONCLUSION(S): GNRHR mutations are a frequent cause of congenital normosmic IHH and should be the first candidate gene for genetic screening in this condition, especially in autosomal recessive familial cases. The founder effect study suggested that the p.R139H mutation arises from a common ancestor in the Brazilian population. Finally, mutations in GNRHR do not appear to be involved in the pathogenesis of CDGP.

Central precocious puberty that appears to be sporadic caused by paternally inherited mutations in the imprinted gene makorin ring finger 3.

CONTEXT: Loss-of-function mutations in makorin ring finger 3 (MKRN3), an imprinted gene located on the long arm of chromosome 15, have been recognized recently as a cause of familial central precocious puberty (CPP) in humans. MKRN3 has a potential inhibitory effect on GnRH secretion. OBJECTIVES: The objective of the study was to investigate potential MKRN3 sequence variations as well as copy number and methylation abnormalities of the 15q11 locus in patients with apparently sporadic CPP. SETTING AND PARTICIPANTS: We studied 215 unrelated children (207 girls and eight boys) from three university medical centers with a diagnosis of CPP. All but two of these patients (213 cases) reported no family history of premature sexual development. First-degree relatives of patients with identified MKRN3 variants were included for genetic analysis. MAIN OUTCOME MEASURES: All 215 CPP patients were screened for MKRN3 mutations by automatic sequencing. Multiplex ligation-dependent probe amplification was performed in a partially overlapping cohort of 52 patients. RESULTS: We identified five novel heterozygous mutations in MKRN3 in eight unrelated girls with CPP. Four were frame shift mutations predicted to encode truncated proteins and one was a missense mutation, which was suggested to be deleterious by in silico analysis. All patients with MKRN3 mutations had classical features of CPP with a median age of onset at 6 years. Copy number and methylation abnormalities at the 15q11 locus were not detected in the patients tested for these abnormalities. Segregation analysis was possible in five of the eight girls with MKRN3 mutations; in all cases, the mutation was inherited on the paternal allele. CONCLUSIONS: We have identified novel inherited MKRN3 defects in children with apparently sporadic CPP, supporting a fundamental role of this peptide in the suppression of the reproductive axis.

Combined use of multiplex ligation-dependent probe amplification and automatic sequencing for identification of KAL1 defects in patients with Kallmann syndrome.

OBJECTIVE: To investigate the role of KAL1 abnormalities in Brazilian patients with Kallmann syndrome. DESIGN: In vitro experiments. SETTING: Academic medical center. PATIENT(S): One hundred fifteen Brazilian patients (98 men) with Kallmann syndrome. INTERVENTION(S): Peripheral blood leukocytes were used to obtain DNA. MAIN OUTCOME MEASURE(S): Direct sequencing and multiplex ligation-dependent probe amplification were used to identify KAL1 abnormalities. RESULT(S): We identified four KAL1 mutations (p.Met1?, p.Ala33Glyfs, p.Arg257*, and p.Trp462*) and two multiple exon deletions (exons 1-2 and 3-14) in six new male patients. Overall, 17 KAL1 defects (14.8%) were identified in the entire cohort of patients with Kallmann syndrome, including previously studied cases. KAL1-mutated patients presented with a more severe reproductive and nonreproductive phenotype (synkinesia, renal malformations, cryptorchidism, and anatomic olfactory abnormalities) in comparison with patients without KAL1 mutations. Intragenic deletions were one of the most often encountered defects (29.4%). These deletions can be missed by polymerase chain reaction (PCR) due to Yq11.2 KAL1 pseudogene (KALP) spurious amplification. CONCLUSION(S): These results indicate that intragenic multiexon deletions are one of the most frequent KAL1 abnormalities, which can be more accurately detected by multiplex ligation-dependent probe amplification. In addition, KAL1 sequencing results should be interpreted with caution, and stringency conditions of the PCR reaction should be adjusted to avoid pseudogene amplification.

Novel mutation in the gonadotropin-releasing hormone receptor (GNRHR) gene in a patient with normosmic isolated hypogonadotropic hypogonadism.

We report a novel GNRHR mutation in a male with normosmic isolated hypogonadotropic hypogonadism (nIHH). The coding region of the GNRHR gene was amplified and sequenced. Three variants p.[Asn10Lys;Gln11Lys]; [Tyr283His] were identified in the GNRHR coding region in a male with sporadic complete nIHH. The three variants were absent in the controls (130 normal adults). Familial segregation showed that the previously described p.Asn10Lys and p.Gln11Lys are in the same allele, in compound heterozygozity with the novel variant p.Tyr283His. The p.[Asn10Lys;Gln11Lys] are known inactivating mutations. The p.Tyr283His affects a well-conserved residue, and in silico analysis suggested it is a deleterious variant. We describe a novel GNRHR mutation in a male with nIHH. Absence of the mutation in the control group, conservation among species, in silico analysis, and familial segregation suggest that p.Tyr283His, which was identified in compound heterozygozity with the p.[Asn10Lys;Gln11Lys] variants, is an inactivating mutation.

Mutational analysis of TAC3 and TACR3 genes in patients with idiopathic central pubertal disorders.

OBJECTIVE: To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. SUBJECTS AND METHODS: Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH), and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. RESULTS: We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C>T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L, and p.W275* variants were identified in three unrelated males with normosmic IHH. CONCLUSION: Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype.

Role of kisspeptin/GPR54 system in human reproductive axis.

The kisspeptin-GPR54 signaling complex is a key gatekeeper of human sexual maturation. Kisspeptins, encoded by the KISS1 gene, constitute a powerful stimulus for gonadotropin-releasing hormone-induced gonadotropin secretion. In addition, the KISS1 gene is a target for regulation by gonadal steroids in both sexes. The increase in hypothalamic kisspeptin expression at puberty is believed to contribute to maturation of the reproductive axis. Homozygous or compound heterozygous loss-of-function mutations in the GPR54 gene have been identified in familial and sporadic patients with isolated hypogonadotropic hypogonadism without olfactory abnormalities. In addition, mice with targeted deletions of Kiss1 or Gpr54 have a similar failure of sexual maturation. Study of these mutations provides an important contribution in the understanding of the role of the kisspeptin/GPR54 system in the control of human puberty development and reproductive function.

TAC3/TACR3 mutations reveal preferential activation of gonadotropin-releasing hormone release by neurokinin B in neonatal life followed by reversal in adulthood.

CONTEXT: Mutations in TAC3 and TACR3 (encoding neurokinin B and its receptor) have been identified in Turkish patients with idiopathic hypogonadotropic hypogonadism (IHH), but broader populations have not yet been tested and genotype-phenotype correlations have not been established. OBJECTIVE: A broad cohort of normosmic IHH probands was screened for mutations in TAC3/TACR3 to evaluate the prevalence of such mutations and define the genotype/phenotype relationships. DESIGN AND SETTING: The study consisted of sequencing of TAC3/TACR3, in vitro functional assays, and neuroendocrine phenotyping conducted in tertiary care centers worldwide. PATIENTS OR OTHER PARTICIPANTS: 345 probands, 18 family members, and 292 controls were studied. INTERVENTION: Reproductive phenotypes throughout reproductive life and before and after therapy were examined. MAIN OUTCOME MEASURE: Rare sequence variants in TAC3/TACR3 were detected. RESULTS: In TACR3, 19 probands harbored 13 distinct coding sequence rare nucleotide variants [three nonsense mutations, six nonsynonymous, four synonymous (one predicted to affect splicing)]. In TAC3, one homozygous single base pair deletion was identified, resulting in complete loss of the neurokinin B decapeptide. Phenotypic information was available on 16 males and seven females with coding sequence variants in TACR3/TAC3. Of the 16 males, 15 had microphallus; none of the females had spontaneous thelarche. Seven of the 16 males and five of the seven females were assessed after discontinuation of therapy; six of the seven males and four of the five females demonstrated evidence for reversibility of their hypogonadotropism. CONCLUSIONS: Mutations in the neurokinin B pathway are relatively common as causes of hypogonadism. Although the neurokinin B pathway appears essential during early sexual development, its importance in sustaining the integrity of the hypothalamic-pituitary-gonadal axis appears attenuated over time.

Molecular analysis of the WNT4 gene in 6 patients with Mayer-Rokitansky-Küster-Hauser syndrome.

Molecular analysis of the WNT4 gene in 6 patients with Mayer-Rokitansky-Küster-Hauser syndrome without androgen excess excluded this gene as a major cause of this syndrome, regardless of the subtype.

Novel mutation in the gonadotropin-releasing hormone receptor (GNRHR) gene in a patient with normosmic isolated hypogonadotropic hypogonadism / Nova mutação no receptor do hormônio liberador de gonadotrofinas (GNRHR) em um paciente com hipogonadismo hipogonadotrófico isolado normósmico

We report a novel GNRHR mutation in a male with normosmic isolated hypogonadotropic hypogonadism (nIHH). The coding region of the GNRHR gene was amplified and sequenced. Three variants p.[Asn10Lys;Gln11Lys]; [Tyr283His] were identified in the GNRHR coding region in a male with sporadic complete nIHH. The three variants were absent in the controls (130 normal adults). Familial segregation showed that the previously described p.Asn10Lys and p.Gln11Lys are in the same allele, in compound heterozygozity with the novel variant p.Tyr283His. The p.[Asn10Lys;Gln11Lys] are known inactivating mutations. The p.Tyr283His affects a well-conserved residue, and in silico analysis suggested it is a deleterious variant. We describe a novel GNRHR mutation in a male with nIHH. Absence of the mutation in the control group, conservation among species, in silico analysis, and familial segregation suggest that p.Tyr283His, which was identified in compound heterozygozity with the p.[Asn10Lys;Gln11Lys] variants, is an inactivating mutation. Arq Bras Endocrinol Metab. 2012;56(8):540-4.

Relatamos uma nova mutação no gene GNRHR em um homem com hipogonadismo hipogonadotrófico isolado normósmico (HHIn). A região codificadora do gene GNRHR foi amplificada e sequenciada. Três variantes p.[Asn10Lys;Gln11Lys]; [Tyr283His] foram identificadas no GNRHR em um homem com HHIn esporádico. As três variantes estavam ausentes no grupo controle (130 adultos normais). A segregação familiar mostrou que as variantes previamente descritas p.[Asn10Lys;Gln11Lys] se localizavam no mesmo alelo, em heterozigose composta com a nova variante p.Tyr283His. As mutações p.[Asn10Lys;Gln11Lys] são sabidamente inativadoras. A variante p.Tyr283His afeta um resíduo bem conservado, e a análise in silico sugeriu que essa é uma mutação deletéria. Descrevemos uma mutação inédita no gene GNRHR em um paciente com HHIn nIHH. A ausência da variante no grupo controle, a conservação entre as espécies, a análise in silico e a segregação familiar sugerem que a p.Tyr283His é uma mutação inativadora, identificada em heterozigose composta com as mutações p.[Asn10Lys;Gln11Lys]. Arq Bras Endocrinol Metab. 2012;56(8):540-4.

Mutational analysis of TAC3 and TACR3 genes in patients with idiopathic central pubertal disorders / Análise de mutações nos genes TAC3 e TACR3 em pacientes com distúrbios puberais centrais idiopáticos

OBJECTIVE: To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. SUBJECTS AND METHODS: Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH), and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. RESULTS: We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C>T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L, and p.W275* variants were identified in three unrelated males with normosmic IHH. CONCLUSION: Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype. Arq Bras Endocrinol Metab. 2012;56(9):646-52.

OBJETIVO: Investigar a presença de variantes nos genes TAC3 e TACR3, os quais codificam a NKB e seu receptor (NK3R), respectivamente, em uma coorte de pacientes com distúrbios puberais centrais idiopáticos. SUJEITOS E MÉTODOS: Duzentos e trinta e sete pacientes foram estudados: 114 com puberdade precoce central (PPC), 73 com hipogonadismo hipogonadotrófico isolado normósmico (HHI) e 50 com retardo constitucional do crescimento e desenvolvimento (RCCD). O grupo controle consistiu de 150 indivíduos brasileiros que apresentaram desenvolvimento puberal normal. O DNA genômico foi extraído de sangue periférico, e as regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas e sequenciadas automaticamente. RESULTADOS: Uma variante (p.A63P) foi identificada na NKB, e quatro variantes, p.G18D, p.L58L (c.172C>T), p.W275X e p.A449S, foram identificadas no NK3R, as quais foram ausentes no grupo controle. A variante p.A63P foi identificada em uma menina com PPC, e a variante p.A449S, em uma menina com RCCD. As variantes previamente descritas, p.G18D, p.L58L e p.W275X, foram identificadas em três indivíduos com HHI normósmico do sexo masculino não relacionados. CONCLUSÃO: Variantes raras nos genes TAC3 e TACR3 foram identificadas em pacientes com distúrbios puberais centrais idiopáticos. Mutações de perda de função no gene TACR3 foram associadas com o fenótipo de HHI normósmico. Arq Bras Endocrinol Metab. 2012;56(9):646-52.