RESUMO
OBJECTIVE: It was to verify the association between the definition of sex of rearing and, clinical and cytogenetic features among patients with genital ambiguity referred without a sex assignment. METHODS: The sample consisted of 133 patients with genital ambiguity seen at a single reference service. These patients did not have a defined social sex at the first consultation and their etiological diagnosis was obtained during follow-up. RESULTS: A total of 133 cases were included, 74 of which were reared as males and 59 as females. No correlation was found between the year of birth and the year of the first consultation with the definition of sex of rearing. However, the definition of sex of rearing was associated with age at the first consultation, severity of genital ambiguity, presence of palpable gonad(s), presence of uterus on ultrasound, karyotype, and diagnosis. Palpable gonad(s), more virilized genitalia, absence of a uterus on ultrasound, 46, XY karyotype, or a karyotype with sex chromosome abnormalities emerged as strong predictors for defining male sex. All 77 (58 %) patients over 18 years old had a gender identity in accordance with the sex of rearing; though 9 of 77 (12 %) had homo or bisexual orientation, especially girls with Congenital Adrenal Hyperplasia. CONCLUSIONS: Clinical and cytogenetic data were strongly associated with the definition of the sex of rearing of children with genital ambiguity referred to a DSD center without sex assignment. Management in a specialized center allows the establishment of a gender identity in accordance with the sex of rearing.
Assuntos
Transtornos do Desenvolvimento Sexual , Humanos , Masculino , Feminino , Criança , Adolescente , Pré-Escolar , Lactente , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/diagnóstico , Identidade de Gênero , CariotipagemRESUMO
INTRODUCTION: NR5A1 is an essential transcription factor that regulates several target genes involved in reproduction and endocrine function. Pathogenic variants in this gene are responsible for a wide spectrum of disorders/differences of sex development (DSD). METHODS: The molecular study involved Sanger sequencing, in vitro assays, and whole exome sequencing (WES). RESULTS: Four variants were identified within the NR5A1 non-coding region in 3 patients with 46,XY DSD. In vitro analyses showed that promoter activity was affected in all cases. WES revealed variants in SRA1, WWOX, and WDR11 genes. DISCUSSION/CONCLUSION: Evaluation of clinical and phenotypic significance of variants located in a non-coding region of a gene can be complex, and little is known regarding their association with DSD. Nevertheless, based on the important region for interaction with cofactors essential to promote appropriated sex development and on our in vitro results, it is feasible to say that an impact on gene expression can be expected and that this may be correlated with the DSD pathophysiology presented in our patients. Considering the number of cases that remain elusive after screening for the well-known DSD related genes, we emphasize the importance of a careful molecular analysis of NR5A1 non-coding region which is commonly neglected and might explain some idiopathic DSD cases.
Assuntos
Transtorno 46,XY do Desenvolvimento Sexual , Transtornos do Desenvolvimento Sexual , Humanos , Mutação , Transtorno 46,XY do Desenvolvimento Sexual/genética , Fenótipo , Fator Esteroidogênico 1/genética , Fator Esteroidogênico 1/metabolismo , Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/genéticaRESUMO
INTRODUCTION: The aim of this retrospective study was to verify the association between the time of diagnosis and initial and final sex assignment in a disorder of sex development (DSD) diagnostic group, looking at the age of the patients at first visit, severity of genital ambiguity, and karyotype. METHODS: The time of diagnosis was divided into 3 groups: before 2000, between 2000 and 2006, and after 2006. Data were categorized and analyzed using the χ2 test with α < 0.05. RESULTS: A total of 567 cases were analyzed; 307 were assigned as male, 135 as female, and 125 remained undefined at the first visit. After clinical and laboratory evaluations, 369 patients were male and 198 were female. Neither initial nor final sex assignment proportions changed over time, but there were significant differences in the age at first visit, with referral occurring at an earlier age, as well as more severe genital ambiguity presentations, a higher proportion of sex chromosome aberrations, and a lower frequency of 46,XX DSD cases. This occurred both in the sample as a whole (567 cases) and in the group of 125 patients without definitive sex assignment at the first visit. The results were similar when only 284 patients aged less than 12 months at the first visit were analyzed. DISCUSSION/CONCLUSION: Over time, there were no changes in sex assignment proportions, but there was an increased awareness of the need for early referral and changes in clinical, cytogenetic, and diagnostic aspects.
Assuntos
Transtornos do Desenvolvimento Sexual , Humanos , Masculino , Feminino , Lactente , Estudos Retrospectivos , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/diagnóstico , Desenvolvimento Sexual , Cariotipagem , CariótipoRESUMO
A region of 160 kb at Xp21.2 has been defined as dosage-sensitive sex reversal (DSS) and includes the NR0B1 gene, considered to be the candidate gene involved in XY gonadal dysgenesis if overexpressed. We describe a girl with 46,XY partial gonadal dysgenesis carrying a 297 kb duplication at Xp21.2 upstream of NR0B1 initially detected by chromosomal microarray analysis. Fine mapping of the breakpoints by whole-genome sequencing showed a tandem duplication of TASL (CXorf21), GK and partially TAB3, upstream of NR0B1. This is the first description of an Xp21.2 duplication upstream of NR0B1 associated with 46,XY partial gonadal dysgenesis.
Assuntos
Disgenesia Gonadal 46 XY , Feminino , Humanos , Receptor Nuclear Órfão DAX-1/genética , Disgenesia Gonadal 46 XY/genéticaRESUMO
The human chorionic gonadotropin (hCG) stimulation test that evaluates gonadal steroidogenesis is crucial in the assessment of patients with 46,XY disorders of sex development (DSD). This study aimed to determine a testosterone (T) cutoff level that indicates an adequate testicular function using LC-MS/MS after stimulation with recombinant human chorionic gonadotropin (rhCG) in a single dose. Nineteen prepubertal children with 46,XY DSD and normal T secretion were evaluated. T and dihydrotestosterone (DHT) levels were measured by liquid chromatography technique with tandem mass spectrometry (LC-MS/MS) before and 7 days after rhCG application at 250 µg. We suggest 0.89 ng/mL as the cutoff point for T after rhCG stimulation analyzed by LC-MS/MS.
Assuntos
Espectrometria de Massas em Tandem , Testosterona , Criança , Humanos , Testosterona/farmacologia , Cromatografia Líquida , Gonadotropina Coriônica/farmacologiaRESUMO
Abstract Objective: To evaluate, in a sample of patients with disorders of sex development (DSD), data related to the age at referral and their correlation with the initial complaints, gender at referral, defined gender after diagnosis and etiological diagnosis. Methods: Retrospective review of the age at the first consultation and the reason for it, initial social gender and gender after the diagnosis, karyotype and etiological diagnosis of all cases treated at a DSD outpatient clinic between 1989 and 2016. Cases that did not involve DSD and DSD diagnoses that do not usually involve ambiguous genitalia, thus not requiring specialized monitoring, were excluded. Results: Of the 1793 treated cases, 1139 were diagnosed with some type of DSD. This study excluded 430 cases (272 with Turner's syndrome, 66 with Klinefelter syndrome, and 92 with pure gonadal dysgenesis), thus a total 709 individuals were included. Of these, 82.9% were referred due to ambiguous genitalia; only one-quarter were still in the first month of life, and 6.6% were referred due to pubertal delay, with most of them aged 10 years or older. Of these patients, 68.6% had a diagnosis of XY DSD, 22.4% of XX DSD, and 9% of sex chromosome abnormalities. Conclusions: This study presents the largest series in the literature of patients with DSD treated in a single center. The time of referral of the majority of patients with ambiguous genitalia fell short of the ideal, and milder cases of ambiguous genitalia and many with pubertal manifestations were referred even later. The results reinforce the importance of continuing education for professionals who will have the first contact with these patients, mainly pediatricians and neonatologists.
Resumo Objetivo: Avaliar em uma amostra de pacientes com distúrbios da diferenciação do sexo (DDS), dados relacionados à idade, ao encaminhamento e sua correlação com as queixas iniciais, ao sexo ao encaminhamento e ao sexo final e diagnóstico etiológico. Métodos: Revisão retrospectiva da idade por ocasião da primeira consulta e motivo dela, sexo social inicial e após definição do diagnóstico, cariótipo e diagnóstico etiológico de todos os casos atendidos em um ambulatório especializado em DDS entre 1989 e 2016. Foram excluídos casos que não compreendiam DDS e diagnósticos de DDS que não cursam comumente com ambiguidade genital, não necessitam de acompanhamento especializado. Resultados: Dos 1.793 casos atendidos, 1.139 foram diagnosticados com algum DDS. Excluíram-se 430 (272 síndrome de Turner, 66 síndrome de Klinefelter e 92 disgenesia gonadal pura), totalizando 709. Desses, 82,9% foram encaminhados por ambiguidade genital, somente um quarto ainda no primeiro mês de vida e 6,6% por atraso puberal, a maioria com 10 anos ou mais; 68,6% tiveram diagnóstico de DDS XY; 22,4% DDS XX e 9% de anomalias dos cromossomos sexuais. Conclusões: Este estudo apresenta a maior casuística na literatura de pacientes com DDS atendidos em um único serviço. O momento de encaminhamento da maioria dos pacientes com ambiguidade genital foi aquém do ideal e casos mais leves de ambiguidade e muitos com manifestações puberais foram encaminhados ainda mais tardiamente. Os resultados reforçam a importância do ensino continuado a profissionais que terão o primeiro contato com esses pacientes, principalmente pediatras e neonatologistas.
Assuntos
Humanos , Criança , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/terapia , Estudos Retrospectivos , Cariótipo , PediatrasRESUMO
Primary ovarian insufficiency (POI) is a heterogeneous disorder associated with several genes. The majority of cases are still unsolved. Our aim was to identify the molecular diagnosis of a Brazilian cohort with POI. Genetic analysis was performed using a customized panel of targeted massively parallel sequencing (TMPS) and the candidate variants were confirmed by Sanger sequencing. Additional copy number variation (CNV) analysis of TMPS samples was performed by CONTRA. Fifty women with POI (29 primary amenorrhea and 21 secondary amenorrhea) of unknown molecular diagnosis were included in this study, which was conducted in a tertiary referral center of clinical endocrinology. A genetic defect was obtained in 70% women with POI using the customized TMPS panel. Twenty-four pathogenic variants and two CNVs were found in 48% of POI women. Of these variants, 16 genes were identified as BMP8B, CPEB1, INSL3, MCM9, GDF9, UBR2, ATM, STAG3, BMP15, BMPR2, DAZL, PRDM1, FSHR, EIF4ENIF1, NOBOX, and GATA4. Moreover, a microdeletion and microduplication in the CPEB1 and SYCE1 genes, respectively, were also identified in two distinct patients. The genetic analysis of eleven patients was classified as variants of uncertain clinical significance whereas this group of patients harbored at least two variants in different genes. Thirteen patients had benign or no rare variants, and therefore the genetic etiology remained unclear. In conclusion, next-generation sequencing (NGS) is a highly effective approach to identify the genetic diagnoses of heterogenous disorders, such as POI. A molecular etiology allowed us to improve the disease knowledge, guide decisions about prevention or treatment, and allow familial counseling avoiding future comorbidities.
Assuntos
Testes Genéticos , Pacientes , Insuficiência Ovariana Primária/genética , Adolescente , Adulto , Animais , Brasil , Estudos de Coortes , Modelos Animais de Doenças , Feminino , Humanos , Padrões de Herança/genética , Adulto JovemRESUMO
OBJECTIVE: To evaluate, in a sample of patients with disorders of sex development (DSD), data related to the age at referral and their correlation with the initial complaints, gender at referral, defined gender after diagnosis and etiological diagnosis. METHODS: Retrospective review of the age at the first consultation and the reason for it, initial social gender and gender after the diagnosis, karyotype and etiological diagnosis of all cases treated at a DSD outpatient clinic between 1989 and 2016. Cases that did not involve DSD and DSD diagnoses that do not usually involve ambiguous genitalia, thus not requiring specialized monitoring, were excluded. RESULTS: Of the 1793 treated cases, 1139 were diagnosed with some type of DSD. This study excluded 430 cases (272 with Turner's syndrome, 66 with Klinefelter syndrome, and 92 with pure gonadal dysgenesis), thus a total 709 individuals were included. Of these, 82.9% were referred due to ambiguous genitalia; only one-quarter were still in the first month of life, and 6.6% were referred due to pubertal delay, with most of them aged 10 years or older. Of these patients, 68.6% had a diagnosis of XY DSD, 22.4% of XX DSD, and 9% of sex chromosome abnormalities. CONCLUSIONS: This study presents the largest series in the literature of patients with DSD treated in a single center. The time of referral of the majority of patients with ambiguous genitalia fell short of the ideal, and milder cases of ambiguous genitalia and many with pubertal manifestations were referred even later. The results reinforce the importance of continuing education for professionals who will have the first contact with these patients, mainly pediatricians and neonatologists.
Assuntos
Transtornos do Desenvolvimento Sexual , Criança , Transtornos do Desenvolvimento Sexual/diagnóstico , Transtornos do Desenvolvimento Sexual/terapia , Humanos , Cariótipo , Pediatras , Estudos RetrospectivosRESUMO
In this study, we present 3 cases of Down syndrome (DS) associated with disorders/differences of sex development (DSD) and review the literature on this topic. Case 1: 1-year-old child with male genitalia and DS phenotype, 47,XX,+21 karyotype and testicular DSD. Case 2: 11-month-old child with male genitalia and few DS dysmorphisms, 45,X/47,XY,+21 karyotype, and mixed gonadal dysgenesis. Case 3: 4-month-old child with female genitalia and DS phenotype, 47,XY,+21 karyotype and XY complete gonadal dysgenesis. In the literature, among 188 patients, 107 (57%) had Klinefelter syndrome and 61 (33%) Turner syndrome, 12 (6%) had mixed gonadal dysgenesis, 2 (1%) had partial androgen insensitivity, 2 (1%) ovotesticular DSD, and the others had congenital adrenal hyperplasia, XY partial gonadal dysgenesis, XY complete gonadal dysgenesis, and complete androgen insensitivity (1 case each). A typical DS phenotype was found in all individuals of the revision, with the exception of one case, but DSD features were not always reported. In conclusion, the association of DS with sex chromosome DSD is the most frequently observed, whereas associations with 46,XX and 46,XY DSD is extremely rare.
RESUMO
BACKGROUND: Clinical suspicion of Turner syndrome (TS) may be challenging. Short stature and absent puberty are not mandatory and the dysmorphic picture is widely variable. The aim of the study was to describe a representative sample of patients with suspected TS in a single center and to verify which set of features may help discriminate those with TS. METHODS: This was a retrospective study of patients with suspected TS evaluated between 1989 and 2012 with the same clinical and cytogenetic protocols. Data regarding reason for referral, age and height at diagnosis, birth data, pubertal features and dysmorphisms were analyzed. RESULTS: TS was diagnosed in 36% of 516 patients; structural chromosome anomalies predominated (42%). Short stature was the main reason for referral of patients with and without TS. The mean age of patients at first visit, with TS or without TS was similar (11.89 and 11.35 years, respectively), however, infants and adolescents predominated in the TS group. The mean full-term birth weight was lower in patients with TS as well as height at diagnosis, but normal height z-score was found in 17% of patients. Spontaneous puberty occurred in 30% of TS patients aged 13 years or more, but most had pubertal delay. Residual lymphedema, webbed neck, cubitus valgus, hyperconvex nails, shield chest, abnormal nipples, pigmented nevi, short fourth metacarpal and shorter height were the best discriminators for girls with TS. CONCLUSIONS: Though short stature, pubertal delay and typical stigmata should prompt investigation of TS, lack of one of these features should not exclude this hypothesis. Dysmorphisms other than those considered "typical" should be sought on physical examination.
Assuntos
Transtornos do Crescimento/etiologia , Linfedema/etiologia , Puberdade Tardia/etiologia , Aberrações dos Cromossomos Sexuais , Síndrome de Turner/diagnóstico , Síndrome de Turner/genética , Adolescente , Fatores Etários , Peso ao Nascer , Estatura , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Diagnóstico Diferencial , Feminino , Hospitais Universitários , Humanos , Lactente , Cariotipagem , Ambulatório Hospitalar , Prevalência , Encaminhamento e Consulta , Estudos Retrospectivos , Síndrome de Turner/epidemiologia , Síndrome de Turner/fisiopatologiaRESUMO
Various disorders of sex development (DSD) result in an abnormal development of genitalia that may be recognized at prenatal ultrasonography, immediately after birth, or later in life. Because of the complex nature of DSD, the participation of a multidisciplinary team, including imaging or radiology technologists, is required to address the patient's medical needs. The first steps in the management of DSD are sex evaluation, which is based on factors such as the genotype, the presence, location, and appearance of reproductive organs, the potential for fertility, and the cultural background and beliefs of the patient's family. It is also important to ensure the detection of comorbidity (as in syndromes) and to define the etiology of DSD in order to offer the best prognosis. Ultrasonography is the primary modality for demonstrating internal organs, genitography is used to assess the urethra, vagina, and any fistulas, and magnetic resonance imaging is used as an additional modality to assess internal gonads and genitalia. This review presents the advantages and disadvantages and the sensitivity and specificity for each type of radiological imaging to help in the evaluation of DSD cases before and after birth.
Assuntos
Diagnóstico por Imagem/métodos , Transtornos do Desenvolvimento Sexual/diagnóstico por imagem , Transtornos do Desenvolvimento Sexual/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
Androgens are responsible for the development and maintenance of male sex characteristics. Dysfunctions in androgen action due to mutations in the androgen receptor gene (AR) can lead to androgen insensitivity syndrome (AIS) that can be classified as mild (MAIS), partial (PAIS), or complete (CAIS). We have analyzed functional effects of p.Ser760Thr, p.Leu831Phe, p.Ile899Phe, p.Leu769Val, and p.Pro905Arg mutations and the combination p.Gln799Glu + p.Cys807Phe that were identified in patients with PAIS or CAIS. The p.Leu769Val and p.Pro905Arg mutations showed complete disruption of AR action under physiological hormone concentrations; however, they differed in high DHT concentrations especially in the N/C terminal interaction assay. Mutations p.Ser760Thr, p.Leu831Phe, p.Ile899Phe presented transactivation activities higher than 20% of the wild type in physiological hormone concentrations and increased with higher DHT concentrations. However, each one showed a different profile in the N/C interaction assay. When p.Gln799Glu and p.Cys807Phe were analyzed in combination, transactivation activities <10% in physiologic hormone conditions indicated an association with a CAIS phenotype. We conclude that the functional analysis elucidated the role of mutant ARs, giving clues for the molecular mechanisms associated with different clinical AIS manifestations. Differences in hormone-dependent profiles may provide a basis for the response to treatment in each particular case.
Assuntos
Síndrome de Resistência a Andrógenos/genética , Receptores Androgênicos/genética , Adolescente , Adulto , Pré-Escolar , Feminino , Humanos , Masculino , Mutação/genética , Receptores Androgênicos/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Adulto JovemRESUMO
Nephrotic syndrome is one of the most common kidney pathologies in childhood, being characterized by proteinuria, edema, and hypoalbuminemia. In clinical practice, it is divided into two categories based on the response to steroid therapy: steroid-sensitive and steroid resistant. Inherited impairments of proteins located in the glomerular filtration barrier have been identified as important causes of nephrotic syndrome, with one of these being podocin, coded by NPHS2 gene. NPHS2 mutations are the most frequent genetic cause of steroid resistant nephrotic syndrome. The aim of this review is to update the list of NPHS2 mutations reported between June 2013 and February 2017, with a closer look to mutations occurring in Latin American countries.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Mutação/genética , Geografia , Humanos , América LatinaRESUMO
Balanced chromosomal rearrangements (BCR) are associated with abnormal phenotypes in approximately 6% of balanced translocations and 9.4% of balanced inversions. Abnormal phenotypes can be caused by disruption of genes at the breakpoints, deletions, or positional effects. Conventional cytogenetic techniques have a limited resolution and do not enable a thorough genetic investigation. Molecular techniques applied to BCR carriers can contribute to the characterization of this type of chromosomal rearrangement and to the phenotype-genotype correlation. Fifteen individuals among 35 with abnormal phenotypes and BCR were selected for further investigation by molecular techniques. Chromosomal rearrangements involved 11 reciprocal translocations, 3 inversions, and 1 balanced insertion. Array genomic hybridization (AGH) was performed and genomic imbalances were detected in 20% of the cases, 1 at a rearrangement breakpoint and 2 further breakpoints in other chromosomes. Alterations were further confirmed by FISH and associated with the phenotype of the carriers. In the analyzed cases not showing genomic imbalances by AGH, next-generation sequencing (NGS), using whole genome libraries, prepared following the Illumina TruSeq DNA PCR-Free protocol (Illumina®) and then sequenced on an Illumina HiSEQ 2000 as 150-bp paired-end reads, was done. The NGS results suggested breakpoints in 7 cases that were similar or near those estimated by karyotyping. The genes overlapping 6 breakpoint regions were analyzed. Follow-up of BCR carriers would improve the knowledge about these chromosomal rearrangements and their consequences.
RESUMO
Hypergonadotropic hypogonadism (HH) is defined by increased gonadotropin levels in men and women. Primary ovarian failure (POF) is a form of female infertility characterized by amenorrhea, hypoestrogenism, and elevated gonadotropin levels in women under the age of 40 years. Although several genes have been associated with POF, its causative genes remain to be identified. Here, we used whole-exome sequencing (WES) to study a consanguineous family with a 46,XX girl and a 46,XY man affected by HH. All exons of both siblings and their parents were captured and massively sequenced by WES, and the candidate variant was confirmed by Sanger sequencing. A novel c.1298C>A;p.Ala433Asp missense variant of the follicle-stimulating hormone receptor (FSHR) gene was found in both affected siblings in a homozygous state and in their parents in a heterozygous state. This FSHR variant is not present in available databases (1000 Genomes and NHLBI/EVS) and Brazilian exome controls. Moreover, it is highly conserved and predicted as deleterious in all prediction sites analyzed. In conclusion, the novel homozygous FSHR variant observed in 2 siblings with HH can expand the spectrum of FSHR mutations in humans.
Assuntos
Hipogonadismo/genética , Mutação de Sentido Incorreto/genética , Receptores do FSH/genética , Irmãos , Adolescente , Adulto , Sequência de Bases , Brasil , Família , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Sequenciamento do ExomaRESUMO
Denys-Drash syndrome (DDS) is characterized by nephropathy, genital abnormalities, and predisposition to Wilms' tumor. DDS patients usually present heterozygous de novo germline WT1 mutations. The WT1 gene comprises 10 exons encoding the N-terminal transactivation and the C-terminal DNA-binding regions. Two unrelated patients with genital ambiguity and Wilms' tumor were analyzed by sequencing of the WT1 gene, and 3 mutations in exon 1 were identified of which 2 are novel. Patient 1 carried a c.555delC mutation that causes a frameshift and a premature stop codon. Patient 2 carried both c.421A>C and c.424C>T aberrations that lead to the missense p.Lys141Gln and the nonsense p.Lys142* mutation, respectively. As both patients were heterozygous for the mutations, we tested their parents who did not carry any mutation. Therefore, the 3 WT1 mutations occurred de novo in both patients. Heterozygous mutations result in WT1 haploinsufficiency as they impair protein production. They are associated with a milder DDS phenotype as observed in the patients studied here.
Assuntos
Síndrome de Denys-Drash/genética , Haploinsuficiência/genética , Proteínas WT1/genética , Códon sem Sentido/genética , Síndrome de Denys-Drash/fisiopatologia , Transtornos do Desenvolvimento Sexual/genética , Éxons/genética , Feminino , Haploinsuficiência/fisiologia , Heterozigoto , Humanos , Lactente , Masculino , Mutação/genética , Tumor de Wilms/genéticaRESUMO
Mutations in the NR5A1 gene, which encodes the steroidogenic factor 1 (SF1), are responsible for different phenotypes of disorders of sex development (DSD), such as bilateral anorchia and hypospadias. Furthermore, they can be associated with primary amenorrhea, premature ovarian failure, male infertility, adrenal tumors, and endometriosis. Direct sequencing of the 7 NR5A1 exons including â¼1,000 bp of the 5'-upstream and 3'-downstream regions and all intron-exon boundaries was performed in patients with DSD. Three different in silico tools were used to assess the consequences of a splice site mutation. As a result, 3 novel NR5A1 mutations were identified in 3 patients with 46,XY partial gonadal dysgenesis: p.Lys38* and p.Leu80Trpfs*8 lead to premature translation termination codons within the SF1 DNA-binding domain, and the intronic nucleotide substitution c.1138+1G>T at the intron 6 donor splice site is considered to modify correct splicing. We assume that the anomalous mRNA produced as a result of p.Lys38* and p.Leu80Trpfs*8 will be degraded by nonsense-mediated mRNA decay even before translation, leading to SF1 haploinsufficiency. The c.1138+1G>T mutation is expected to produce a truncated protein. Heterozygous SF1 loss-of-function mutations in these cases resulted in mild DSD manifestations, such as dysgenetic testes, spontaneous puberty, and preserved adrenal function.
Assuntos
Transtorno 46,XY do Desenvolvimento Sexual/genética , Fator Esteroidogênico 1/genética , Códon sem Sentido/genética , Éxons/genética , Disgenesia Gonadal 46 XY/genética , Disgenesia Gonadal 46 XY/fisiopatologia , Gônadas/metabolismo , Gônadas/fisiologia , Humanos , Hipospadia/genética , Hipospadia/fisiopatologia , Lactente , Infertilidade Masculina/genética , Infertilidade Masculina/fisiopatologia , Íntrons/genética , Masculino , Mutação , Testículo/anormalidades , Testículo/fisiopatologiaRESUMO
AIM: Autosomal recessive mutations in NPHS1 gene are a common cause of congenital nephrotic syndrome (CNS). The disorder is characterized by massive proteinuria that manifests in utero or in the neonatal period during the first 3 months of life. NPHS1 encodes nephrin, a member of the immunoglobulin family of cell adhesion molecules and the main protein expressed at the renal slit diaphragm. Currently, there are approximately 250 mutations described in the NPHS1 gene distributed among all nephrin domains. The main objective of this study was to perform the analysis of the NPHS1 gene in patients with congenital nephrotic syndrome in order to determine the molecular cause of the disease. METHODS: Direct sequencing of NPHS1 gene in four children was performed. RESULTS: Each patient was heterozygous for two pathogenic mutations disclosing the molecular cause of the disease in 100% of the cases. We identified six different mutations, consisting of one in-frame deletion, one frameshift, and four missense substitutions. The p.Val736Met mutation that is described here for the first time was considered pathogenic by different mutation predictive algorithms. Regardless of the type of mutation, three patients had a bad outcome and died CONCLUSIONS: Despite the small size of the cohort, this study contributed to the increasing number of deleterious mutations in the NPHS1 gene by describing a new mutation. Also, since we identified NPHS1 pathogenic mutations as the cause of the disease in all cases analyzed, it might be a frequent cause of CNS in the South Eastern region of Brazil, although the analysis of a larger sample is required to obtain more indicative epidemiological data.
Assuntos
Proteínas de Membrana/genética , Mutação , Síndrome Nefrótica/genética , Brasil , Pré-Escolar , Análise Mutacional de DNA , Evolução Fatal , Feminino , Marcadores Genéticos , Predisposição Genética para Doença , Heterozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Nefrectomia , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/cirurgia , Fenótipo , Resultado do TratamentoRESUMO
BACKGROUND: Nephrotic syndrome is traditionally classified on the basis of the response to standard steroid treatment. Mutations in more than 24 genes have been associated with nephrotic syndrome in children, although the great majority of steroid-resistant cases have been attributed to mutations in three main genes: NPHS1, NPHS2 and WT1. The aims of this study were to identify mutations in these genes more frequently reported as mutated and to characterize each variation using different in silico prediction algorithms in order to understand their biological functions. METHODS: We performed direct sequence analysis of exons 8 and 9 of WT1, 8 exons of NPHS2 and 29 exons of NPHS1, including NPHS2 and NPHS1 intron-exon boundary sequences, as well as 700 bp of the 5' UTR from both genes in 27 steroid-resistant patients aged between 3 months and 18 years. RESULTS: Analysis of the NPHS2 gene revealed four missense mutations, one frameshift mutation and three variations in the 5' UTR. Four patients presented compound heterozygosis, and four other patients presented one heterozygous alteration only. WT1 and NPHS1 gene analysis did not reveal any mutations. DISCUSSION: This is the first study focusing on genetics of SRNS in Brazilian children. Identification of mutations is important because it could influence physicians' decision on patient treatment, as patients carrying mutations can be spared the side effects of immunosuppressive therapy and ultimately could be considered for kidney transplantation from a living donor. CONCLUSIONS: After molecular analysis of the genes more frequently reported as mutated in 27 steroid-resistant nephrotic syndrome patients, we identified NPHS2 mutations confirming the hereditary character of the kidney disease in only 14.8% of patients. Therefore, the next step is to perform a next generation sequencing based analysis of glomeluropathy-related panel of genes for the remaining patients in order to search for mutations in other genes related to steroid-resistant nephrotic syndrome.
Assuntos
Regiões 5' não Traduzidas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Síndrome Nefrótica/genética , Adolescente , Sequência de Bases , Criança , Pré-Escolar , Biologia Computacional , Primers do DNA/genética , Mutação da Fase de Leitura/genética , Humanos , Lactente , Dados de Sequência Molecular , Mutação de Sentido Incorreto/genética , Análise de Sequência de DNA , Proteínas WT1/genéticaRESUMO
The androgen insensitivity syndrome (AIS) is described as a dysfunction of the androgen receptor (AR) in 46,XY individuals, which can be associated with mutations in the AR gene or can be due to unknown mechanisms. Different mutations in AIS generally cause variable phenotypes that range from a complete hormone resistance to a mild form usually associated with male infertility. The purpose of this study was to search for mutations in the AR gene in a fertile man with gynecomastia and to evaluate the influence of the mutation on the AR transactivation ability. Sequencing of the AR gene revealed the p.Pro695Ser mutation. It is located within the AR ligand-binding domain. Bioinformatics analysis indicated a deleterious role, which was verified after testing transactivation activity and N-/C-terminal (N/C) interaction by in vitro expression of a reporter gene and 2-hybrid assays. p.Pro695Ser showed low levels of both transactivation activity and N/C interaction at low dihydrotestosterone (DHT) conditions. As the ligand concentration increased, both transactivation activity and N/C interaction also increased and reached normal levels. Therefore, this study provides functional insights for the p.Pro695Ser mutation described here for the first time in a patient with mild AIS. The expression profile of p.Pro695Ser not only correlates to the patient's phenotype, but also suggests that a high-dose DHT therapy may overcome the functional deficit of the mutant AR.