Gil Guerra

Novel mutations affecting SRY DNA-binding activity: the HMG box N65H associated with 46,XY pure gonadal dysgenesis and the familial non-HMG box R30I associated with variable phenotypes.

Abstract. The SRY gene (sex-determining region of the Y chromosome) initiates the process of male sex differentiation in mammalians. In humans mutations in the SRY gene have been reported to account for 10–15% of the XY sex reversal cases. We describe here two novel missense mutations in the SRY gene after the screening of 17 patients, including 3 siblings, with 46,XY gonadal dysgenesis and 4 true hermaphrodites. One of the mutations, an A to C transversion within the HMG box, causes the N65H substitution and it was found in a patient presenting 46,XY pure gonadal dysgenesis. The Escherichia coli expressed SRYN65H protein did not present DNA-binding activity in vitro. The other mutation, a G to T transversion, causes the R30I substitution. This mutation was found in affected and nonaffected members of a family, including the father, two siblings with partial gonadal dysgenesis, a phenotypic female with pure gonadal dysgenesis, and three nonaffected male siblings. The G to T base change was not found in the SRY sequence of 100 normal males screened by ASO-PCR. The R30I mutation is located upstream to the HMG box, within the 29RRSSS33 phosphorylation site. The E. coli expressed SRYR30I protein was poorly phosphorylated and consequently showed reduced DNA-binding capacity in vitro.

Classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a cross-sectional study of factors involved in bone mineral density.

Glucocorticoids are essential in the treatment of patients with congenital adrenal hyperplasia (CAH). The opposite actions of glucocorticoids and androgens in bone mass achievement justify a study of bone mineral density (BMD) in these patients. We evaluated BMD in patients with CAH due to classic 21-hydroxylase (CYP21A2) deficiency and investigated the involvement of clinical and laboratory factors in the BMD. This study assessed the clinical and laboratory factors involved in BMD of 45 patients at the Pediatric Unit of Endocrinology, UNICAMP, who had been diagnosed as having classical CAH due to CYP21A2 deficiency including molecular characterization. The sample consisted of 28 females and 17 males; 23 salt-wasting (SW) and 22 simple virilizing (SV) cases, with average of 9.9 years (ranges, 5.1–16.3 years) when bone densitometry was performed. The DEXA method was used for calculating the areal BMD Z score in L2–L4. The variables were analyzed with reference to the BMD for chronological age (BMD/CA), height age (BMD/HA), and bone age (BMD/BA). The mean Z score for BMD/CA was 0.08 ± 1.21 (−2.55 to 2.64); it was 0.29 ± 1.33 (−2.01 to 4.00) for BMD/HA, and −0.90 ± 1.24 (−3.41 to 1.92) for BMD/BA. The BMD/CA was significantly lower in females and in patients on treatment for a long period and of more advanced chronological age. Weight and body mass index (BMI) Z scores showed a positive correlation with advanced BA. The higher the weight and BMI Z scores, the higher the BMD/HA. The BMD/BA values were significantly higher in the group in which BA was closer to CA. The BMD/BA value was significantly lower when compared to the value obtained with height and chronological ages. Sex, duration of treatment, weight, BMI, and bone age have an effect on areal BMD in patients with CAH due to CYP21A2 deficiency, which may be underestimated when evaluated in relation to CA and HA.

Bone mineralization in Turner syndrome: a transverse study of the determinant factors in 58 patients

Abstract. Turner syndrome (TS) is characterized by the presence of an X chromosome and total or partial loss of the second sex chromosome, short stature, hypergonadotrophic hypogonadism, and a variable dysmorphic picture. Delayed puberty and estrogen deficiency are some of the determinant factors of osteoporosis in TS, but the whether or not there is an intrinsic bone defect is still obscure. The aim of this study was to evaluate the correlation of the z score of bone mineral density (BMD) with age, weight, height, karyotype, associated diseases, bone age, and estrogen therapy in TS patients. We performed a transverse study with area BMD of L2–L4 with dual-energy X-ray absorptiometry (DEXA) in 58 patients with a cytogenetic diagnosis of TS, whose ages ranged from 5 to 29 years. It was observed that 86% of the patients presented with a BMD z score below −1 SD, and 46.5% with a value below −2.5 SD. There was a significant negative association of BMD with age and height, and a positive association with weight and bone mass index (BMI) z scores. A higher BMD was observed in patients with spontaneous puberty and in those with more than 2 years of hormone replacement. In conclusion, there was a high incidence of reduced bone mass among our patients, which was influenced by weight and BMI, by the use and the time of estrogen replacement, and by the presence of spontaneous puberty.

Family-based association of HLA class II alleles and haplotypes with type I diabetes in Brazilians reveals some characteristics of a highly diversified population.

The association of HLA class II haplotypes with type I diabetes was analyzed in 56 Southeastern Brazilian families using affected family-based controls (AFBAC) method. DRB1-DQA1-DQB1 alleles were determined by polymerase chain reaction/sequence-specific primer genotyping. This study first revealed the great haplotype diversity of Brazilians (65 different haplotypes even with incomplete DRB1 subtyping), probably due to the admixture of Africans genes with European and Amerindian genes in this population. The results revealed increased frequencies of the DRB1*03-DQA1*0501-DQB1*02 and DRB1*0401-DQA1*03-DQB1*0302 haplotypes in the patient group The highest risk for type I diabetes was associated with the heterozygote DRB1*03/*04 genotype as largely reported, and DRB1*03/X and DRB1*04/Y genotypes conferred a significant, but much lower disease risk. Protection from type I diabetes revealed some peculiarities in Southeastern Brazilians: a lack of significant protecting effect of the DRB1*1501-DQA1*0102-DQB1*0602 haplotype, and an apparent protection conferred by the DRB1*13-DQB1*0301, DRB1*11-DQB1*0301, and DRB1*01-DQB1*0501 two-locus haplotypes. The risk to type I diabetes in the highly diversified Southeastern Brazilians evidenced specific information to the prediction of the disease in this region of the country.

Estudo multicêntrico de pacientes brasileiros com deficiência da 21-hidroxilase: correlação do genótipo com o fenótipo

ABSTRACT Multicentric Study of Brazilian Patients With 21-Hydroxylase Defi-ciency: A Genotype-Phenotype Correlation. We analyzed the clinical and molecular data of 205 patients with thethree different clinical forms of 21-hydroxylase deficiency, in whom theclinical and molecular diagnosis were already defined. The most fre-quent mutations were I2 splice in the salt wasting form, I172N in the sim-ple virilizing and V281L in the nonclassical form, presenting similar fre-quencies as those observed in other populations. We found a lower fre-quency of 21-hydroxylase gene deletion, similar to that previously iden-tified in Argentinean and Mexican populations. Five new mutations weredescribed in our population: G424S, H28+C, Ins 1003^1004 A, R408C andIVS2-2A>G. The genotype was classified in three groups according to theimpairment of enzymatic activity observed in vitro , Group A: 0-2%, GroupB: 3-7% and Group C: >20%. Group A mutations correlated with the saltwasting form, the Group B with simple virilizing form and Group C withthe non classical form. The severity of genotype showed a positive cor-

Screening of autosomal gene deletions in patients with hypogonadotropic hypogonadism using multiplex ligation-dependent probe amplification: detection of a hemizygosis for the fibroblast growth factor receptor 1

Objective  Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin‐releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons.

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 SRY coding region. Sequencing analysis of the SRY promoter 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.

A percepção da doença em portadoras da síndrome de Turner

OBJECTIVE: To identify how patients with Turner syndrome perceive their condition. METHODS: Thirty-six women with Turner syndrome, aged between 15 and 25 years and with over 2 years of medical follow-up, were individually interviewed about: the impact of Turner syndrome at the moment of the diagnosis, their understanding of the syndrome, its effect in their lives, and their expectations for the future. RESULTS: Only 31% of the patients immediately understood the diagnosis. Their feelings associated to that moment were neutral (47%) or concerned (33%). About one third of the interviewed women were unable to explain the etiology of Turner syndrome (42%), did not relate their symptoms with Turner syndrome (36%), and/or believe there might be a cure for it (44%). Although most of the interviewed women affirm that the syndrome has no interference in their lives (67%) and that they consider themselves happy persons (78%), in more than half of the interviews there are evidences of difficulties in social interaction and love relationship, low self-esteem, dissatisfaction with their physical appearances, especially the short stature and infertility. Their hopes for the future refer mainly to study and have a job. Although being, on average, 19 years old, one in two women (53%) still hopes to grow up. CONCLUSION: Besides medical treatment, it is important that the knowledge of the patients about the syndrome and some issues as infertility, short stature, self-esteem and social interactions receive proper and continuous attention from the moment of the diagnosis. The ideal situation should be a joint-action of a psychologist and the medical team.OBJECTIVE To identify how patients with Turner syndrome perceive their condition. METHODS Thirty-six women with Turner syndrome, aged between 15 and 25 years and with over 2 years of medical follow-up, were individually interviewed about: the impact of Turner syndrome at the moment of the diagnosis, their understanding of the syndrome, its effect in their lives, and their expectations for the future. RESULTS Only 31% of the patients immediately understood the diagnosis. Their feelings associated to that moment were neutral (47%) or concerned (33%). About one third of the interviewed women were unable to explain the etiology of Turner syndrome (42%), did not relate their symptoms with Turner syndrome (36%), and/or believe there might be a cure for it (44%). Although most of the interviewed women affirm that the syndrome has no interference in their lives (67%) and that they consider themselves happy persons (78%), in more than half of the interviews there are evidences of difficulties in social interaction and love relationship, low self-esteem, dissatisfaction with their physical appearances, especially the short stature and infertility. Their hopes for the future refer mainly to study and have a job. Although being, on average, 19 years old, one in two women (53%) still hopes to grow up. CONCLUSION Besides medical treatment, it is important that the knowledge of the patients about the syndrome and some issues as infertility, short stature, self-esteem and social interactions receive proper and continuous attention from the moment of the diagnosis. The ideal situation should be a joint-action of a psychologist and the medical team.

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 (r2 = 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.

Associação singular de síndrome de Kallmann e cisto aracnóide da fossa média: relato de caso

Hypogonadotrophic hypogonadism can result from different abnormalities in the central nervous system. The clinical picture depends upon the time of onset the deficiency, the magnitude of the gonadotropins deficiency and whether there are other pituitary hormone deficiencies as well. We report on a 18-year-old boy, who was investigated because of pubertal and growth delay. He also had learning disabilities. On physical examination he exhibited mild eunuchoid aspect, 162 cm height (z score = -2,17), pubertal development on stage G II, P II, and 4 cm5 testis. Laboratory investigation revealed pre-pubertal levels of testosterone and normal results of the combined test of anterior pituitary function, except for in GnRH acute and prolonged test. Brain CT showed an arachnoid cyst on left middle fossa with expansion to suprasellar cisterna. He was diagnosed as having hypogonadotrophic hypogonadism secondary to compression by the cyst, and a cyst-peritoneal derivation was performed. After surgery there was no improvement of the pubertal state and bilateral anosmia was discovered, so Kallmanns syndrome was then diagnosed and was confirmed by MRI, even though the hormonal results are not totally matched with the refered syndrome. We did not find in the literature any description of the association between Kallmanns syndrome and arachnoid cyst and we believe that in this case the results of the hormonal measurement may be due to such association that provoked an additional hypophysis dysfunction.