Sex dimorphism of weight and length at birth: evidence based on disorders of sex development.

BACKGROUND: Males have higher weight and length at birth than females. AIM: To verify the influence of the Y chromosome and the action of intrauterine androgens on weight and length at birth of children with Disorders of Sex Development (DSD). SUBJECTS AND METHODS: A cross-sectional and retrospective study. Patients with Turner syndrome (TS), complete (XX and XY), mixed (45,X/46,XY) and partial (XY) gonadal dysgenesis (GD), complete (CAIS) and partial (PAIS) androgen insensitivity syndromes and XX and XY congenital adrenal hyperplasia (CAH) were included. Weight and length at birth were evaluated. RESULTS: Weight and length at birth were lower in TS and mixed GD when compared to XY and XX DSD cases. In turn, patients with increased androgen action (117 cases) had higher weight and length at birth when compared to those with absent (108 cases) and decreased (68 cases) production/action. In birthweight, there was a negative influence of the 45,X/46,XY karyotype and a positive influence of increased androgen and gestational age. In birth length, there was a negative influence of the 45,X and 45,X/46,XY karyotypes and also a positive influence of increased androgen and gestational age. CONCLUSIONS: The sex dimorphism of weight and length at birth could possibly be influenced by intrauterine androgenic action.

Association between serotonin 2C receptor gene (HTR2C) polymorphisms and psychopathological symptoms in children and adolescents.

Serotonin 2C receptors (5HT2C) are involved in serotonin-driven dynamic equilibrium adjustments responsible for homeostatic stability in brain structures that modulate behavior and emotions. Single nucleotide polymorphisms (SNPs) from the serotonin 2C receptor gene (HTR2C) have been associated with several neurological and mental disorders, including abnormalities in cognitive and emotional processes. The aim of this study was to evaluate the association between the rs6318 SNP of the HTR2C gene and behavioral characteristics exhibited by children and adolescents based on the Child Behavior Checklist (CBCL/6-18) inventory. Eighty-five psychiatric outpatients between 8 and 18 years of age underwent genotyping of the rs6318 SNP. The CBCL/6-18 scale was administered to their caregivers. The chi-squared test was used to assess differences in the frequency of C and G alleles of the rs6318 SNP relative to the grouped CBCL/6-18 scores; significance level was 5%. The presence of the G allele of rs6318 was found to be associated with characteristics of aggressive behavior and social problems, and aggressive behavior was found to be associated with heterozygosis in females. These findings contribute to the identification of mental and behavioral phenotypes associated with gene expression.

Association between serotonin 2C receptor gene (HTR2C) polymorphisms and psychopathological symptoms in children and adolescents

Serotonin 2C receptors (5HT2C) are involved in serotonin-driven dynamic equilibrium adjustments responsible for homeostatic stability in brain structures that modulate behavior and emotions. Single nucleotide polymorphisms (SNPs) from the serotonin 2C receptor gene (HTR2C) have been associated with several neurological and mental disorders, including abnormalities in cognitive and emotional processes. The aim of this study was to evaluate the association between the rs6318 SNP of the HTR2C gene and behavioral characteristics exhibited by children and adolescents based on the Child Behavior Checklist (CBCL/6-18) inventory. Eighty-five psychiatric outpatients between 8 and 18 years of age underwent genotyping of the rs6318 SNP. The CBCL/6-18 scale was administered to their caregivers. The chi-squared test was used to assess differences in the frequency of C and G alleles of the rs6318 SNP relative to the grouped CBCL/6-18 scores; significance level was 5%. The presence of the G allele of rs6318 was found to be associated with characteristics of aggressive behavior and social problems, and aggressive behavior was found to be associated with heterozygosis in females. These findings contribute to the identification of mental and behavioral phenotypes associated with gene expression.

GAPO syndrome: a new syndromic cause of premature ovarian insufficiency.

Premature ovarian insufficiency has the following causes: genetic, autoimmune, metabolic, infectious, and iatrogenic dysfunctions (including radiotherapy, chemotherapy and surgery). However, premature ovarian insufficiency remains without a definite cause in a substantial number of cases. This article describes GAPO syndrome in association with premature ovarian insufficiency, as well as a novel ANTXR1 gene mutation. Histopathological study of the ovaries of a woman with hypergonadotropic hypogonadism revealed extensive deposition of hyaline extracellular material, with bilateral parenchymal atrophy and follicular depletion. Molecular study revealed a novel ANTXR1 gene mutation. The homozygous c.378 + 3A > G transition at the consensus donor splice site of intron 4 was identified. Our results support the involvement of ANTRX1 gene mutations in deregulated extracellular matrix. In addition, our study identified a novel ANTXR1 mutation causing GAPO syndrome, indicating it as a new cause of early loss of ovarian function.

Two Novel Mutations in the Thyroid Hormone Receptor ß in Patients with Resistance to Thyroid Hormone (RTH ß): Clinical, Biochemical, and Molecular Data.

The syndrome of resistance to thyroid hormone (RTH ß) is an inherited disorder characterized by variable tissue hyposensitivity to 3,5,30-L-triiodothyronine (T(3)), with persistent elevation of free-circulating T(3) (FT(3)) and free thyroxine (FT(4)) levels in association with nonsuppressed serum thyrotropin (TSH). Clinical presentation is variable and the molecular analysis of THRB gene provides a short cut diagnosis. Here, we describe 2 cases in which RTH ß was suspected on the basis of laboratory findings. The diagnosis was confirmed by direct THRB sequencing that revealed 2 novel mutations: the heterozygous p.Ala317Ser in subject 1 and the heterozygous p.Arg438Pro in subject 2. Both mutations were shown to be deleterious by SIFT, PolyPhen, and Align GV-GD predictive methods.

The effect of fetal androgen metabolism-related gene variants on external genitalia virilization in congenital adrenal hyperplasia.

The 21-hydroxylase deficiency (21OHD) is caused by CYP21A2 mutations resulting in severe or moderate enzymatic impairments. 21OHD females carrying similar genotypes present different degrees of external genitalia virilization, suggesting the influence of other genetic factors. Single nucleotide variants (SNVs) in the CYP3A7 gene and in its transcription factors, related to fetal 19-carbon steroid metabolism, could modulate the genital phenotype. To evaluate the influence of the 21OHD genotypes and the CYP3A7, PXR and CAR SNVs on the genital phenotype in 21OHD females. Prader scores were evaluated in 183 patients. The CYP3A7, PXR and CAR SNVs were screened and the 21OHD genotypes were classified according to their severity: severe and moderate groups. Patients with severe genotype showed higher degree of genital virilization (Prader median III, IQR III-IV) than those with moderate genotype (III, IQR II-III) (p < 0.001). However, a great overlap was observed between genotype groups. Among all the SNVs tested, only the CAR rs2307424 variant correlated with Prader scores (r(2) = 0.253; p = 0.023). The CYP21A2 genotypes influence the severity of genital virilization in 21OHD females. We also suggest that the CAR variant, which results in a poor metabolizer phenotype, could account for a higher degree of external genitalia virilization.

Use of transgenic seeds in Brazilian agriculture and concentration of agricultural production to large agribusinesses.

We identified the commercial releases of genetically modified organisms (GMOs) in Brazil, their characteristics, the types of genetic transformation used, and the companies responsible for the development of these GMOs, classifying them into two categories: private companies, subdivided into multinational and national, and public institutions. The data came from the data bank of the national registration of cultivars and the service of national protection of cultivars of the Ministry of Agriculture, Fishing and Supply (MAPA). This survey was carried out from 1998 to February 12, 2011. Until this date, 27 GMOs had been approved, including five for soybean, 15 for maize and seven for cotton cultivars. These GMOs have been used for the development of 766 cultivars, of which, 305 are soybean, 445 are maize, and 13 are cotton cultivars. The Monsato Company controls 73.2% of the transgenic cultivars certified by the MAPA; a partnership between Dow AgroSciences and DuPont accounts for 21.4%, and Syngenta controls 4.96%. Seed supply by these companies is almost a monopoly supported by law, giving no choice for producers and leading to the fast replacement of conventional cultivars by transgenic cultivars, which are expensive and exclude small producers from the market, since seeds cannot be kept for later use. This situation concentrates production in the hands of a few large national agribusiness entrepreneurs.

OCT4 immunohistochemistry may be necessary to identify the real risk of gonadal tumors in patients with Turner syndrome and Y chromosome sequences.

BACKGROUND: The aim of this study was to investigate the frequency of gonadal tumors among patients with Turner syndrome (TS) carrying Y-derivative sequences in their chromosomal constitution. METHODS: Six out of 260 patients with TS were selected based on mosaicism of the entire Y chromosome; 10 were included because Y-derivative sequences have been detected by PCR with specific oligonucleotides (sex-determining region on the Y, testis specific-protein, Y and DYZ3) and further confirmed by FISH. The 16 patients were subjected to bilateral gonadectomy at ages varying from 8.7 to 18.2 years. Both histopathological investigation with hematoxylin and eosin (H&E) and immunohistochemical analysis with anti-octamer-binding transcription factor 4 (OCT4) antibody were performed. RESULTS: Gonadal neoplasia was not detected in any of the 32 gonads evaluated by H&E; however, four gonads (12%) from three patients (19%) had positive OCT4 staining in 50-80% of nuclei, suggesting the existence of germ cell tumors (gonadoblastoma or in situ carcinoma). CONCLUSIONS: Evaluation of the real risk of development of gonadal tumors in TS patients with Y-derivative sequences in their chromosomal constitution may require a specific histopathological study, such as immunohistochemistry with OCT4.

Revisiting the Brazilian scenario of registry and protection of cultivars: an analysis of the period from 1998 to 2010, its dynamics and legal observations.

During the last 20 years, the national production of grains has increased 156.1%; productivity increased 93.8% and there has been an increase of 29.1% in cultivated area. Currently, agribusiness is responsible for 40% of Brazilian exports. Nevertheless, there is little quantitative information on the main plant species of economic interest that have been registered and protected in the Agriculture, Fisheries and Food Supply Ministry (MAPA) by public and private companies, as well as by public-private partnerships. Consequently, we investigated the registry and protection of 27 species of economic interest, including the 15 that are the basis of the Brazilian diet, based on the information available on the site CultivarWeb, of MAPA, for the period from 1998 to August 30, 2010. We also examined the legislation that regulates registration and protection procedures and its implications for plant breeding and plant product development. It was found that the private sector controls 73.1% of the registrations and 53.56% of the protections, while 10.73% of the protections were of material developed overseas. Public-private partnerships contributed little to the development of new cultivars, with 0.5% of the registries and 3.61% of the protections. We conclude that plant protection directed private investment to development of wheat and rice varieties, with the greatest public investments directed to corn and sorghum. After the Cultivar Protection Law was implemented, there was restriction of access to germplasm banks, which could inhibit advances in Brazilian plant breeding programs, indicating a need for revision of this legal barrier.

The novel p.E89K mutation in the SRY gene inhibits DNA binding and causes the 46,XY disorder of sex development

Male sex determination in humans is controlled by the SRY gene, which encodes a transcriptional regulator containing a conserved high mobility group box domain (HMG-box) required for DNA binding. Mutations in the SRY HMG-box affect protein function, causing sex reversal phenotypes. In the present study, we describe a 19-year-old female presenting 46,XY karyotype with hypogonadism and primary amenorrhea that led to the diagnosis of 46,XY complete gonadal dysgenesis. The novel p.E89K missense mutation in the SRY HMG-box was identified as a de novo mutation. Electrophoretic mobility shift assays showed that p.E89K almost completely abolished SRY DNA-binding activity, suggesting that it is the cause of SRY function impairment. In addition, we report the occurrence of the p.G95R mutation in a 46,XY female with complete gonadal dysgenesis. According to the three-dimensional structure of the human SRY HMG-box, the substitution of the conserved glutamic acid residue by the basic lysine at position 89 introduces an extra positive charge adjacent to and between the positively charged residues R86 and K92, important for stabilizing the HMG-box helix 2 with DNA. Thus, we propose that an electrostatic repulsion caused by the proximity of these positive charges could destabilize the tip of helix 2, abrogating DNA interaction.

The novel p.E89K mutation in the SRY gene inhibits DNA binding and causes the 46,XY disorder of sex development.

Male sex determination in humans is controlled by the SRY gene, which encodes a transcriptional regulator containing a conserved high mobility group box domain (HMG-box) required for DNA binding. Mutations in the SRY HMG-box affect protein function, causing sex reversal phenotypes. In the present study, we describe a 19-year-old female presenting 46,XY karyotype with hypogonadism and primary amenorrhea that led to the diagnosis of 46,XY complete gonadal dysgenesis. The novel p.E89K missense mutation in the SRY HMG-box was identified as a de novo mutation. Electrophoretic mobility shift assays showed that p.E89K almost completely abolished SRY DNA-binding activity, suggesting that it is the cause of SRY function impairment. In addition, we report the occurrence of the p.G95R mutation in a 46,XY female with complete gonadal dysgenesis. According to the three-dimensional structure of the human SRY HMG-box, the substitution of the conserved glutamic acid residue by the basic lysine at position 89 introduces an extra positive charge adjacent to and between the positively charged residues R86 and K92, important for stabilizing the HMG-box helix 2 with DNA. Thus, we propose that an electrostatic repulsion caused by the proximity of these positive charges could destabilize the tip of helix 2, abrogating DNA interaction.

Association between AKT1 but not AKTIP genetic variants and increased risk for suicidal behavior in bipolar patients.

We tested the hypothesis that the presence of AKT1 and AKTIP polymorphisms, target genes that encode key proteins in the signaling of dopaminergic and serotonergic systems, is associated with suicidal behavior in bipolar patients. The subjects were 273 patients diagnosed with bipolar disorder I or II (age = 41.4 +/- 12.9). TaqMan single-nucleotide polymorphism genotyping assays (AKT1: rs2494731, rs3803304, rs3730358, rs10149779, rs2494746, rs1130214 and rs249878; AKTIP: rs9302648 and rs7189819) were used. We found that the AKT1 marker showed an association with suicide attempts (rs1130214, P < 0.05) and attempted violent attacks (rs2494746, P < 0.05). One out of the seven tested markers of AKT1 attained significant genotype association with violent attempt (rs2494731; P < 0.05). A significant association was detected in the AKT1 haplotype test. We did not observe an association between suicidal behavior and AKTIP variants and also did not find an interaction between AKTIP and AKT1 polymorphisms. In addition, we found that demographic and clinical data are associated with lifetime history of suicide attempts. Our data suggest that demographic and clinical characteristics and AKT1 single markers and haplotypes, but not AKTIP polymorphisms or interactions between AKT1 and AKTIP, are associated with increased risk for suicidal behavior in bipolar patients.

Inhibition of CYP21A2 enzyme activity caused by novel missense mutations identified in Brazilian and Scandinavian patients.

BACKGROUND: Most patients with 21-hydroxylase deficiency carry CYP21A1P-derived mutations, but an increasing number of novel and rare mutations have been reported in disease-causing alleles. OBJECTIVE: Functional effects of three novel (p.G56R, p.L107R, p.L142P) and one recurrent (p.R408C) CYP21A2 mutations were investigated. The degree of enzyme impairment caused by p.H62L alone or combined to p.P453S was also analyzed. DESIGN: The study included 10 Brazilian and two Scandinavian patients. To determine the deleterious role of each mutant protein, in vitro assays were performed in transiently transfected COS-1 cells. For a correct genotype-phenotype correlation, the enzymatic activities were evaluated toward the two natural substrates, 17-hydroxyprogesterone and progesterone. RESULTS: Low levels of residual activities obtained for p.G56R, p.L107R, p.L142P, and p.R408C mutants classified them as classical congenital adrenal hyperplasia mutations, whereas the p.H62L showed an activity within the range of nonclassical mutations. Apparent kinetic constants for p.H62L confirmed the nonclassical classification as the substrate binding capacity was within the same magnitude for mutant and normal enzymes. A synergistic effect was observed for the allele bearing the p.H62L+p.P453S combination because it caused a significant reduction in the enzymatic activity. CONCLUSIONS: We describe the functional analysis of five rare missense mutations identified in Brazilian and Scandinavian patients. The p.G56R, p.L107R, and p.L142P are reported for the first time. Most probably these novel mutations are closer to null than the p.I172N, but for the p.G56R, that might not be the case, and the p.H62L is definitely a nonclassical mutation.

A naturally occurring deletion in the SRY promoter region affecting the Sp1 binding site is associated with sex reversal.

Male to female sex reversal results from failure of testis development. Mutations in the SRY gene or in other genes involved in the sexual differentiation pathway are considered to cause XY gonadal dysgenesis. The majority of the mutations in the SRY described so far are located within the SRY coding region, mainly in the HMG-box conserved domain. Comparison of 5' flanking SRY gene sequences among different species indicated the presence of several putative conserved consensus sequences for different transcription regulators. In this study, we investigated a 360 bp sequence encompassing the SRY putative core promoter, in 17 patients with variable degrees of 46,XY sex reversal, which have been previously shown not to bear mutations in the SRYcoding region. Sequencing analysis of the SRYpromoter in one patient with complete XY gonadal dysgenesis revealed a three base pair deletion in one of the Sp1 binding sites. The deletion abolished Sp1 binding in vitro. This is the first report on a naturally occurring mutation affecting the Sp1 regulatory element in the SRY promoter region, which is associated with sex reversal. Additionally, upon familial investigation the father, who had 18 genital surgeries due to severe hypospadia without cryptorchidism, was found to bear the same deletion and several relatives were referred to have sexual ambiguity.

Mutations in SRY and WT1 genes required for gonadal development are not responsible for XY partial gonadal dysgenesis.

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

Mutations in SRY and WT1 genes required for gonadal development are not responsible for XY partial gonadal dysgenesis

The WT1 transcription factor regulates SRY expression during the initial steps of the sex determination process in humans, activating a gene cascade leading to testis differentiation. In addition to causing Wilms' tumor, mutations in WT1 are often responsible for urogenital defects in men, while SRY mutations are mainly related to 46,XY pure gonadal dysgenesis. In order to evaluate their role in abnormal testicular organogenesis, we screened for SRY and WT1 gene mutations in 10 children with XY partial gonadal dysgenesis, 2 of whom with a history of Wilms' tumor. The open reading frame and 360 bp of the 5' flanking sequence of the SRY gene, and the ten exons and intron boundaries of the WT1 gene were amplified by PCR of genomic DNA. Single-strand conformation polymorphism was initially used for WT1 mutation screening. Since shifts in fragment migration were only observed for intron/exon 4, the ten WT1 exons from all patients were sequenced manually. No mutations were detected in the SRY 5' untranslated region or within SRY open-reading frame sequences. WT1 sequencing revealed one missense mutation (D396N) in the ninth exon of a patient who also had Wilms' tumor. In addition, two silent point mutations were found in the first exon including one described here for the first time. Some non-coding sequence variations were detected, representing one new (IVS4+85A>G) and two already described (-7ATG T>G, IVS9-49 T>C) single nucleotide polymorphisms. Therefore, mutations in two major genes required for gonadal development, SRY and WT1, are not responsible for XY partial gonadal dysgenesis.

Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil.

BACKGROUND: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil. PRIMARY OBJECTIVE: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: São Luis City, in Maranhão State and Campinas City, in São Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background. SUBJECT AND METHODS: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, DI0S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African-American populations as well as for other Brazilian groups. RESULTS: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil. CONCLUSIONS: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region: both populations are in Hardy Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia

Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76 percent of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19 percent), V281L (18 percent), and IVS2,A/C>G,-12 (15 percent). In the SW form, the most frequent mutation was IVS2,A/C>G,-12 (38 percent), in the SV form it was I172N (53 percent), and in the NC form it was V281L (57.7 percent). We observed a good correlation between genotype and phenotype. Discordance between genotype and phenotype was found in one SV patient with a mild mutation in one of the alleles (R356W/V281L). However, we cannot rule out the presence of an additional mutation in these alleles. We also observed a good correlation of genotype with 17alpha-hydroxyprogesterone, testosterone, and androstenedione levels. The severity of external genitalia virilization correlated with the severity of mutation. In conclusion, the frequencies described in the present study did not differ from worldwide studies, including the Brazilian population. The few differences observed may reflect individual sample variations. This new Brazilian cohort study suggests the presence of new mutations in Brazilian patients with different forms of CAH-21OH

Phenotype and genotype correlation of the microconversion from the CYP21A1P to the CYP21A2 gene in congenital adrenal hyperplasia.

Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). We determined by allele-specific PCR the frequency of microconversion in the CYP21A2 gene in 50 Brazilian patients with the classical (salt wasting: SW and simple virilizing: SV) forms and nonclassical (NC) form of CAH-21OH and correlated genotype with phenotype. Genotypes were classified into three mutation groups (A, B, and C) based on the amount of enzymatic activity in in vitro studies using adrenal cells. In 94 unrelated alleles, we diagnosed 76% of the affected alleles after screening for 7 microconversions. The most frequent point mutations observed in this series were I172N (19%), V281L (18%), and IVS2,A/C>G,-12 (15%). In the SW form, the most frequent mutation was IVS2,A/C>G,-12 (38%), in the SV form it was I172N (53%), and in the NC form it was V281L (57.7%). We observed a good correlation between genotype and phenotype. Discordance between genotype and phenotype was found in one SV patient with a mild mutation in one of the alleles (R356W/V281L). However, we cannot rule out the presence of an additional mutation in these alleles. We also observed a good correlation of genotype with 17alpha-hydroxyprogesterone, testosterone, and androstenedione levels. The severity of external genitalia virilization correlated with the severity of mutation. In conclusion, the frequencies described in the present study did not differ from worldwide studies, including the Brazilian population. The few differences observed may reflect individual sample variations. This new Brazilian cohort study suggests the presence of new mutations in Brazilian patients with different forms of CAH-21OH.