RESUMEN
Missense mutations in the gene, MAP3K1, are a common cause of 46,XY gonadal dysgenesis, accounting for 15-20% of cases [Ostrer, 2014, Disorders of sex development (DSDs): an update. J. Clin. Endocrinol. Metab., 99, 1503-1509]. Functional studies demonstrated that all of these mutations cause a protein gain-of-function that alters co-factor binding and increases phosphorylation of the downstream MAP kinase pathway targets, MAPK11, MAP3K and MAPK1. This dysregulation of the MAP kinase pathway results in increased CTNNB1, increased expression of WNT4 and FOXL2 and decreased expression of SRY and SOX9. Unique and recurrent pathogenic mutations cluster in three semi-contiguous domains outside the kinase region of the protein, a newly identified N-terminal domain that shares homology with the Guanine Exchange Factor (residues Met164 to Glu231), a Plant HomeoDomain (residues Met442 to Trp495) and an ARMadillo repeat domain (residues Met566 to Glu862). Despite the presence of the mutation clusters and clinical data, there exists a dearth of mechanistic insights behind the development imbalance. In this paper, we use structural modeling and functional data of these mutations to understand alterations of the MAP3K1 protein and the effects on protein folding, binding and downstream target phosphorylation. We show that these mutations have differential effects on protein binding depending on the domains in which they occur. These mutations increase the binding of the RHOA, MAP3K4 and FRAT1 proteins and generally decrease the binding of RAC1. Thus, pathologies in MAP3K1 disrupt the balance between the pro-kinase activities of the RHOA and MAP3K4 binding partners and the inhibitory activity of RAC1.
Asunto(s)
Trastornos del Desarrollo Sexual/genética , Quinasa 1 de Quinasa de Quinasa MAP/genética , MAP Quinasa Quinasa Quinasa 4/genética , Proteína de Unión al GTP rac1/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas del Dominio Armadillo/genética , Trastorno del Desarrollo Sexual 46,XY , Trastornos del Desarrollo Sexual/patología , Femenino , Proteína Forkhead Box L2/genética , Regulación de la Expresión Génica/genética , Disgenesia Gonadal 46 XY/genética , Disgenesia Gonadal 46 XY/patología , Humanos , Quinasa 1 de Quinasa de Quinasa MAP/química , MAP Quinasa Quinasa Quinasa 4/química , Sistema de Señalización de MAP Quinasas/genética , Masculino , Mutación Missense/genética , Unión Proteica/genética , Proteínas Proto-Oncogénicas/genética , Proteína de la Región Y Determinante del Sexo/genética , Proteína de Unión al GTP rac1/química , Proteína de Unión al GTP rhoA/química , Proteína de Unión al GTP rhoA/genéticaRESUMEN
Short stature homeobox (SHOX) haploinsufficiency is a frequent cause of short stature. Despite advances in sequencing technologies, the identification of SHOX mutations continues to be performed using standard methods, including multiplex ligation-dependent probe amplification (MLPA) followed by Sanger sequencing. We designed a targeted panel of genes associated with growth impairment, including SHOX genomic and enhancer regions, to improve the resolution of next-generation sequencing for SHOX analysis. We used two software packages, CONTRA and Nexus Copy Number, in addition to visual analysis to investigate the presence of copy number variants (CNVs). We evaluated 15 patients with previously known SHOX defects, including point mutations, deletions and a duplication, and 77 patients with idiopathic short stature (ISS). The panel was able to confirm all known defects in the validation analysis. During the prospective evaluation, we identified two new partial SHOX deletions (one detected only by visual analysis), including an intragenic deletion not detected by MLPA. Additionally, we were able to determine the breakpoints in four cases. Our results show that the designed panel can be used for the molecular investigation of patients with ISS, and it may even detect CNVs in SHOX and its enhancers, which may be present in a significant fraction of patients.
Asunto(s)
Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento , Mutación , Proteína de la Caja Homeótica de Baja Estatura/genética , Variaciones en el Número de Copia de ADN , Análisis Mutacional de ADN , Femenino , Genotipo , Humanos , Masculino , FenotipoRESUMEN
Molecular diagnosis is rarely established in 46,XX testicular (T) disorder of sex development (DSD) individuals with atypical genitalia. The Wilms' tumour factor-1 (WT1) gene is involved in early gonadal development in both sexes. Classically, WT1 deleterious variants are associated with 46,XY disorders of sex development (DSD) because of gonadal dysgenesis. We report a novel frameshift WT1 variant identified in an SRY-negative 46,XX testicular DSD girl born with atypical genitalia. Target massively parallel sequencing involving DSD-related genes identified a novel heterozygous WT1 c.1453_1456del; p.Arg485Glyfs*14 variant located in the fourth zinc finger of the protein which is absent in the population databases. Segregation analysis and microsatellite analysis confirmed the de novo status of the variant that is predicted to be deleterious by in silico tools and to increase WT1 target activation in crystallographic model. This novel and predicted activating frameshift WT1 variant leading to the 46,XX testicular DSD phenotype includes the fourth zinc-finger DNA-binding domain defects in the genetic aetiology of 46,XX DSD.
Asunto(s)
Trastornos del Desarrollo Sexual 46, XX/diagnóstico , Patología Molecular , Enfermedades Testiculares/diagnóstico , Proteínas WT1/genética , Trastornos del Desarrollo Sexual 46, XX/genética , Trastornos del Desarrollo Sexual 46, XX/patología , Niño , Proteínas de Unión al ADN/genética , Femenino , Heterocigoto , Humanos , Lactante , Masculino , Mutación , Fenotipo , Desarrollo Sexual/genética , Enfermedades Testiculares/genética , Enfermedades Testiculares/patología , Testículo/patologíaRESUMEN
Androgen insensitivity syndrome (AIS) is caused by defects in the androgen receptor (AR) gene and is the most common aetiology of 46,XY disorders of sex development. Allelic variants in the AR gene are found in 90% of complete AIS (CAIS), but in only 28% to 50% of cases of partial AIS. Even a single nucleic acid change can disrupt splicing sites or splicing regulatory sequences, resulting in inadequate exon and intron recognition, ultimately leading to an aberrant transcript. Therefore, we tested the feasibility of conducting AR cDNA analysis from whole blood and from gonadal tissue in a patient with CAIS due to AR synonymous mutation (c.1530C > T, p.Ser510Ser; NM_000044.3), which led to an aberrant splicing site causing deletion of 92 nucleotides resulting in a very short transcript. AR cDNA sequencing was similar in the whole blood and in the gonadal tissue, with similar evidence of a consequent altered AR transcript. We propose that analysis of AR RNA extracted from whole blood with AR DNA sequencing can help to improve the frequency of molecular diagnosis, particularly for partial AIS.
Asunto(s)
Ácidos Nucleicos Libres de Células , Empalme del ARN , ARN Mensajero/genética , Receptores Androgénicos/genética , Alelos , Síndrome de Resistencia Androgénica/diagnóstico , Síndrome de Resistencia Androgénica/genética , Exones , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Intrones , Masculino , Mutación , ARN Mensajero/sangre , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Follow-up data on patients with 46,XY partial gonadal dysgenesis (PGD) until adulthood are scarce, making information on prognosis difficult. OBJECTIVE: To analyse the long-term outcomes of patients with 46,XY PGD regarding testosterone production, germ cell tumour risk, genotype and psychosexual adaptation. METHODS: A retrospective longitudinal study of 33 patients (20 assigned male and 13 patients assigned female at birth). Molecular diagnosis was performed by Sanger sequencing or by targeted massively parallel sequencing of 63 genes related to disorders of sex development (DSDs). RESULTS: Age at first and last visit ranged from 0.1 to 43 and from 17 to 53 years, respectively. Spontaneous puberty was observed in 57% of the patients. During follow-up, six of them had a gonadectomy (four due to female gender, and two because of a gonadal tumour). At last evaluation, five of six patients had adult male testosterone levels (median 16.7 nmol/L, range 15.3-21.7 nmol/L) and elevated LH and FSH levels. Germ cell tumours were found in two postpubertal patients (one with an abdominal gonad and one patient with Frasier syndrome). Molecular diagnosis was possible in 11 patients (33%). NR5A1 variants were the most prevalent molecular defects (n = 6), and four of five patients harbouring them developed spontaneous puberty. Gender change was observed in four patients, two from each sex assignment group; all patients reported satisfaction with their gender at final evaluation. Sexual intercourse was reported by 81% of both gender and 82% of them reported satisfaction with their sexual lives. CONCLUSION: Spontaneous puberty was observed in 57% of the patients with 46,XY PGD, being NR5A1 defects the most prevalent ones among all the patients and in those with spontaneous puberty. Gender change due to gender dysphoria was reported by 12% of the patients. All the patients reported satisfaction with their final gender, and most of them with their sexual life.
RESUMEN
BACKGROUND: Mutations in PROP1, HESX1 and LHX3 are associated with combined pituitary hormone deficiency (CPHD) and orthotopic posterior pituitary lobe (OPP). OBJECTIVE: To identify mutations in PROP1, HESX1 and LHX3 in a large cohort of patients with CPHD and OPP (35 Brazilian, two Argentinian). DESIGN AND METHODS: We studied 23 index patients with CPHD and OPP (six familial and 17 sporadic) as well as 14 relatives. PROP1 was sequenced by the Sanger method in all except one sporadic case studied using a candidate gene panel. Multiplex ligation-dependent probe amplification (MLPA) was applied to one familial case in whom PROP1 failed to amplify by PCR. In the 13 patients without PROP1 mutations, HESX1 and LHX3 were sequenced by the Sanger method. RESULTS: We identified PROP1 mutations in 10 index cases. Three mutations were novel: one affecting the initiation codon (c.1A>G) and two affecting splicing sites, c.109+1G>A and c.342+1G>C. The known mutations, c.150delA (p.Arg53Aspfs*112), c.218G>A (p.Arg73His), c.263T>C (p.Phe88Ser) and c.301_302delAG (p.Leu102Cysfs*8), were also detected. MLPA confirmed complete PROP1 deletion in one family. We did not identify HESX1 and LHX3 mutations by Sanger. CONCLUSION: PROP1 mutations are a prevalent cause of congenital CPHD with OPP, and therefore, PROP1 sequencing must be the first step of molecular investigation in patients with CPHD and OPP, especially in populations with a high frequency of PROP1 mutations. In the absence of mutations, massively parallel sequencing is a promising approach. The high prevalence and diversity of PROP1 mutations is associated with the ethnic background of this cohort.
Asunto(s)
Proteínas de Homeodominio/genética , Hipopituitarismo/genética , Proteínas con Homeodominio LIM/genética , Mutación/genética , Neurohipófisis/metabolismo , Factores de Transcripción/genética , Adolescente , Adulto , Brasil , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Beckwith-Wiedemann syndrome (BWS) is a common genetic congenital disease characterized by somatic overgrowth and its broad clinical spectrum includes pre- and post-natal macrosomia, macroglossia, visceromegaly, increased risk of neonatal hypoglycemia, and development of embryonic tumors. BWS occurs due to genetic/epigenetic changes involving growth-regulating genes, located on region 11p15, with an important genotype-phenotype correlation. Congenital adrenal hyperplasia (CAH) comprises a spectrum of autosomal recessive diseases presenting a variety of clinical manifestations due to a deficiency in one of the enzymes involved in cortisol secretion. Early diagnosis based on newborn screening prevents the adrenal crisis and early infant death. However, high 17-hydroxyprogesterone (17-OHP) levels can occur in newborns or premature infants without CAH, in situations of stress due to maternal or neonatal factors. Here, we report new cases of false-positive diagnosis of 21-hydroxylase deficiency during newborn screening - two girls and one boy with BWS. Methylation-specific multiplex ligation-dependent probe amplification revealed a gain of methylation in the H19 differentially methylated region. Notably, all three cases showed a complete normalization of biochemical changes, highlighting the transient nature of these hormonal findings that imitate the classical form of CAH. This report sheds light on a new cause of false-positive 21-hydroxylase deficiency diagnosis during newborn screening: Beckwith-Wiedemann syndrome.
Asunto(s)
Hiperplasia Suprarrenal Congénita , Síndrome de Beckwith-Wiedemann , Masculino , Lactante , Femenino , Humanos , Recién Nacido , Síndrome de Beckwith-Wiedemann/diagnóstico , Síndrome de Beckwith-Wiedemann/genética , Hiperplasia Suprarrenal Congénita/diagnóstico , Hiperplasia Suprarrenal Congénita/genética , Metilación de ADN , Tamizaje NeonatalRESUMEN
OBJECTIVES: To analyze the efficiency of a multigenic targeted massively parallel sequencing panel related to endocrine disorders for molecular diagnosis of patients assisted in a tertiary hospital involved in the training of medical faculty. MATERIAL AND METHODS: Retrospective analysis of the clinical diagnosis and genotype obtained from 272 patients in the Endocrine unit of a tertiary hospital was performed using a custom panel designed with 653 genes, most of them already associated with the phenotype (OMIM) and some candidate genes that englobes developmental, metabolic and adrenal diseases. The enriched DNA libraries were sequenced in NextSeq 500. Variants found were then classified according to ACMG/AMP criteria, with Varsome and InterVar. RESULTS: Three runs were performed; the mean coverage depth of the targeted regions in panel sequencing data was 249×, with at least 96.3% of the sequenced bases being covered more than 20-fold. The authors identified 66 LP/P variants (24%) and 27 VUS (10%). Considering the solved cases, 49 have developmental diseases, 12 have metabolic and 5 have adrenal diseases. CONCLUSION: The application of a multigenic panel aids the training of medical faculty in an academic hospital by showing the picture of the molecular pathways behind each disorder. This may be particularly helpful in developmental disease cases. A precise genetic etiology provides an improvement in understanding the disease, guides decisions about prevention or treatment, and allows genetic counseling.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Estudios Retrospectivos , Centros de Atención Terciaria , Mutación/genética , FenotipoRESUMEN
Context: Polycystic ovary syndrome (PCOS) etiology remains to be elucidated, but familial clustering and twin studies have shown a strong heritable component. Objective: The purpose of this study was to identify rare genetic variants that are associated with the etiology of PCOS in a preselected cohort. Methods: This prospective study was conducted among a selected group of women with PCOS. The study's inclusion criteria were patients with PCOS diagnosed by the Rotterdam criteria with the following phenotypes: severe insulin resistance (IR), normoandrogenic-normometabolic phenotype, adrenal hyperandrogenism, primary amenorrhea, and familial PCOS. Forty-five patients were studied by target sequencing, while 8 familial cases were studied by whole exome sequencing. Results: Patients were grouped according to the inclusion criteria with the following distribution: 22 (41.5%) with severe IR, 13 (24.5%) with adrenal hyperandrogenism, 7 (13.2%) with normoandrogenic phenotype, 3 (5.7%) with primary amenorrhea, and 8 (15.1%) familial cases. DNA sequencing analysis identified 1 pathogenic variant in LMNA, 3 likely pathogenic variants in INSR, PIK3R1, and DLK1, and 6 variants of uncertain significance level with interesting biologic rationale in 5 genes (LMNA, GATA4, NR5A1, BMP15, and FSHR). LMNA was the most prevalent affected gene in this cohort (3 variants). Conclusion: Several rare variants in genes related to IR were identified in women with PCOS. Although IR is a common feature of PCOS, patients with extreme or atypical phenotype should be carefully evaluated to rule out monogenic conditions.
RESUMEN
Wilms' tumor suppressor gene 1 (WT1) plays an essential role in urogenital and kidney development. Heterozygous germline pathogenic allelic variants of WT1 have been classically associated with Denys-Drash syndrome (DDS) and Frasier syndrome (FS). Usually, exonic pathogenic missense variants in the zinc finger region are the cause of DDS, whereas pathogenic variants affecting the canonic donor lysine-threonine-serine splice site in intron 9 cause FS. Phenotypic overlap between WT1 disorders has been frequently observed. New WT1 variant-associated phenotypes, such as 46,XX testicular/ovarian-testicular disorders of sex development (DSD) and primary ovarian insufficiency, have been reported. In this report, we describe the phenotypes and genotypes of 7 Brazilian patients with pathogenic WT1 variants. The molecular study involved Sanger sequencing and massively parallel targeted sequencing using a DSD-associated gene panel. Six patients (5 with a 46,XY karyotype and 1 with a 46,XX karyotype) were initially evaluated for atypical genitalia, and a 46,XY patient with normal female genitalia sought medical attention for primary amenorrhea. Germ cell tumors were identified in 2 patients, both with variants affecting alternative splicing of WT1 between exons 9 and 10. Two pathogenic missense WT1 variants were identified in two 46,XY individuals with Wilms' tumors; both patients were <1 year of age at the time of diagnosis. A novel WT1 variant, c.1453_1456 (p.Arg485Glyfs*14), was identified in a 46,XX patient with testicular DSD. Nephrotic proteinuria was diagnosed in all patients, including 3 who underwent renal transplantation after progressing to end-stage kidney disease. The expanding phenotypic spectrum associated with WT1 variants in XY and XX individuals confirms their pivotal role in gonadal and renal development as well as in tumorigenesis, emphasizing the clinical implications of these variants in genetic diagnosis.
Asunto(s)
Neoplasias Renales , Desarrollo Sexual , Proteínas WT1 , Tumor de Wilms , Femenino , Humanos , Lactante , Masculino , Mutación/genética , Fenotipo , Proteínas WT1/genética , Tumor de Wilms/genéticaRESUMEN
Hypospadias is a common congenital disorder of male genital formation. Children born small for gestational age (SGA) present a high frequency of hypospadias of undetermined etiology. No previous study investigated the molecular etiology of hypospadias in boys born SGA using massively parallel sequencing. Our objective is to report the genetic findings of a cohort of patients born SGA with medium or proximal hypospadias. We identified 46 individuals with this phenotype from a large cohort of 46,XY DSD patients, including 5 individuals with syndromic features. DNA samples from subjects were studied by either whole exome sequencing or target gene panel approach. Three of the syndromic patients have 5 main clinical features of Silver-Russell syndrome (SRS) and were first studied by MLPA. Among the syndromic patients, loss of DNA methylation at the imprinting control region H19/IGF2 was identified in 2 individuals with SRS clinical diagnosis. Two novel pathogenic variants in compound heterozygous state were identified in the CUL7 gene establishing the diagnosis of 3M syndrome in one patient, and a novel homozygous variant in TRIM37 was identified in another boy with Mulibrey nanism phenotype. Among the non-syndromic subjects, 7 rare heterozygous variants were identified in 6 DSD-related genes. However, none of the variants found can explain the phenotype by themselves. In conclusion, a genetic defect that clarifies the etiology of hypospadias was not found in most of the non-syndromic SGA children, supporting the hypothesis that multifactorial causes, new genes, and/or unidentified epigenetic defects may have an influence in this condition.
Asunto(s)
Trastorno del Desarrollo Sexual 46,XY , Hipospadias , Metilación de ADN/genética , Trastorno del Desarrollo Sexual 46,XY/genética , Edad Gestacional , Humanos , Hipospadias/complicaciones , Hipospadias/genética , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Masculino , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
CONTEXT: Massively parallel sequencing (MPS) technologies have emerged as a first-tier approach for diagnosing several pediatric genetic syndromes. However, MPS has not been systematically integrated into the diagnostic workflow along with clinical/biochemical data for diagnosing 46,XY differences of sex development (DSD). OBJECTIVE: To analyze the contribution of phenotypic classification either alone or in association with genetic evaluations, mainly MPS, for diagnosing a large cohort of 46,XY DSD patients. DESIGN/PATIENTS: 209 nonsyndromic 46,XY DSD index cases from a Brazilian DSD center were included. Patients were initially classified into 3 subgroups according to clinical and biochemical data: gonadal dysgenesis (GD), disorders of androgen secretion/action, and DSD of unknown etiology. Molecular genetic studies were performed by Sanger sequencing and/or MPS. RESULTS: Clinical/biochemical classification into either GD or disorders of hormone secretion/action was obtained in 68.4% of the index cases. Among these, a molecular diagnosis was obtained in 36% and 96.5%, respectively. For the remainder 31.6% classified as DSD of clinically unknown etiology, a molecular diagnosis was achieved in 31.8%. Overall, the molecular diagnosis was achieved in 59.3% of the cohort. The combination of clinical/biochemical and molecular approaches diagnosed 78.9% of the patients. Clinical/biochemical classification matched with the genetic diagnosis in all except 1 case. DHX37 and NR5A1 variants were the most frequent genetic causes among patients with GD and DSD of clinical unknown etiology, respectively. CONCLUSIONS: The combination of clinical/biochemical with genetic approaches significantly improved the diagnosis of 46,XY DSD. MPS potentially decreases the complexity of the diagnostic workup as a first-line approach for diagnosing 46,XY DSD.
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Trastorno del Desarrollo Sexual 46,XY , Disgenesia Gonadal , Niño , Estudios de Cohortes , Trastorno del Desarrollo Sexual 46,XY/diagnóstico , Trastorno del Desarrollo Sexual 46,XY/genética , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Mutación , Desarrollo Sexual/genéticaRESUMEN
Heterozygous SHOX defects are observed in about 50 to 90% of patients with Leri-Weill dyschondrosteosis (LWD), a common dominant inherited skeletal dysplasia; and in 2 to 15% of children with idiopathic short stature (ISS), indicating that SHOX defects are the most important monogenetic cause of short stature. In addition, children selected by disproportionate idiopathic short stature had a higher frequency of SHOX mutations (22%). A careful clinical evaluation of family members with short stature is recommended since it usually revealed LWD patients in families first classified as having ISS or familial short stature. SHOX-molecular analysis is indicated in families with LWD and ISS children with disproportionate short stature. Treatment with recombinant human growth hormone is considered an accepted approach to treat short stature associated with isolated SHOX defect. Here we review clinical, molecular and therapeutic aspects of SHOX haploinsufficiency.
Asunto(s)
Estatura/genética , Trastornos del Crecimiento , Proteínas de Homeodominio/genética , Trastornos del Crecimiento/diagnóstico , Trastornos del Crecimiento/genética , Trastornos del Crecimiento/terapia , Haplotipos , Humanos , Proteína de la Caja Homeótica de Baja EstaturaRESUMEN
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.
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Pruebas Genéticas , Pacientes , Insuficiencia Ovárica Primaria/genética , Adolescente , Adulto , Animales , Brasil , Estudios de Cohortes , Modelos Animales de Enfermedad , Femenino , Humanos , Patrón de Herencia/genética , Adulto JovenRESUMEN
BACKGROUND/AIM: Primary ovarian insufficiency (POI) is characterized by primary or secondary amenorrhea, infertility, low estradiol levels, and increased gonadotropin levels. Most cases of POI remain unsolved even after exhaustive investigation. Here, we performed a targeted massively parallel sequencing to identify the genetic diagnosis of primary ovarian insufficiency (POI) in a Brazilian patient. PATIENT AND METHODS: An adopted 21-year-old Brazilian woman with isolated POI was selected. A custom SureSelectXT DNA target enrichment panel was designed and sequenced on an Illumina NextSeq 500 sequencer. The variants were confirmed using Sanger sequencing. RESULTS: Two rare heterozygous pathogenic variants in the STAG3 gene were identified in our patient. An unpublished 1-bp duplication c.291dupC (p.Asn98Glnfs*2) and one stop codon variant c.1950C > A (p.Tyr650*) were identified in the STAG3 gene. Both undescribed heterozygous variants were absent in the public databases [1000Genomes, Exome Aggregation Consortium (ExAC), National Heart, Lung, and Blood Institute Exome Variant Server (NHLBI/EVS), database of Single Nucleotide Polymorphisms (dbSNP), Genome Aggregation Database (gnomAD)], and Online Archive of Brazilian Mutations (ABraOM) databases. Moreover, neither heterozygous variants were found in 400 alleles from fertile Brazilian women screened by Sanger sequencing. The parents' DNA was not available to segregate these variants. CONCLUSION: Our results suggested that POI is caused by pathogenic compound heterozygous variants in the STAG3 gene, supporting the key role of the STAG3 gene in the etiology of primary ovarian insufficiency.
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Mutación con Pérdida de Función , Proteínas Nucleares/genética , Insuficiencia Ovárica Primaria/genética , Proteínas de Ciclo Celular , Femenino , Humanos , Insuficiencia Ovárica Primaria/patología , Adulto JovenRESUMEN
The first description of patients with combined pituitary hormone deficiencies (CPHD) caused by PROP1 mutations was made 20 years ago. Here we updated the clinical and genetic characteristics of patients with PROP1 mutations and summarized the phenotypes of 14 patients with 7 different pathogenic PROP1 mutations followed at the Hospital das Clínicas of the University of Sao Paulo. In addition to deficiencies in GH, TSH, PRL and gonadotropins some patients develop late ACTH deficiency. Therefore, patients with PROP1 mutations require permanent surveillance. On magnetic resonance imaging, the pituitary stalk is normal, and the posterior lobe is in the normal position. The anterior lobe in patients with PROP1 mutations is usually hypoplastic but may be normal or even enlarged. Bi-allelic PROP1 mutations are currently the most frequently recognized genetic cause of CPHD worldwide. PROP1 defects occur more frequently among offspring of consanguineous parents and familial cases, but they also occur in sporadic cases, especially in countries in which the prevalence of PROP1 mutations is relatively high. We classified all reported PROP1 variants described to date according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) guidelines: 29 were pathogenic, 2 were likely pathogenic, and 2 were of unknown significance. An expansion of the phenotype of patients with PROP1 mutations was observed since the first description 20 years ago: variable anterior pituitary size, different pathogenic mutations, and late development of ACTH deficiency. PROP1 mutations are the most common cause of autosomal recessive CPHD with a topic posterior pituitary lobe. Arch Endocrinol Metab. 2019;63(2):167-74.
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Proteínas de Homeodominio/genética , Hipopituitarismo/genética , Mutación/genética , Femenino , Humanos , Hipopituitarismo/diagnóstico , Masculino , Fenotipo , Displasia Septo-Óptica/genéticaRESUMEN
CONTEXT: Primary ovarian insufficiency (POI) is a cause of female infertility. However, the genetic etiology of this disorder remains unknown in most patients with POI. OBJECTIVE: To investigate the genetic etiology of idiopathic POI. PATIENTS AND METHODS: We performed whole-exome sequencing of 11 families with idiopathic POI. To gain insights into the potential mechanisms associated with this mutation, we generated two mouse lines via clustered regularly interspaced short palindromic repeats/Cas9 technology. RESULTS: A pathogenic homozygous missense mutation (c.149A>G; p.Asp50Gly) in the POLR3H gene in two unrelated families was identified. Pathogenic mutations in this subunit have not been associated with human disorders. Loss-of-function Polr3h mutation in mice caused early embryonic lethality. Mice with homozygous point mutation (Polr3hD50G) were viable but showed delayed pubertal development, characterized by late first estrus or preputial separation. The Polr3hD50G female and male mice showed decreased fertility later in life, associated with small litter size and increased time to pregnancy or to impregnate a female. Polr3hD50G mice displayed decreased expression of ovarian Foxo3a and lower numbers of primary follicles. CONCLUSION: Our manuscript provides a case of POI caused by missense mutation in POLR3H, expanding the knowledge of molecular pathways of the ovarian function and human infertility. Screening of the POLR3H gene may elucidate POI cases without previously identified genetic causes, supporting approaches of genetic counseling.
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Insuficiencia Ovárica Primaria/genética , ARN Polimerasa III/genética , Adolescente , Animales , Sistemas CRISPR-Cas , Niño , Femenino , Proteína Forkhead Box O3/metabolismo , Técnicas de Inactivación de Genes , Heterocigoto , Homocigoto , Humanos , Infertilidad/genética , Tamaño de la Camada , Mutación con Pérdida de Función , Masculino , Ratones , Mutación Missense , Ovario/metabolismo , Maduración Sexual/genética , Tiempo para Quedar Embarazada , Secuenciación del ExomaRESUMEN
SUMMARY Beckwith-Wiedemann syndrome (BWS) is a common genetic congenital disease characterized by somatic overgrowth and its broad clinical spectrum includes pre- and post-natal macrosomia, macroglossia, visceromegaly, increased risk of neonatal hypoglycemia, and development of embryonic tumors. BWS occurs due to genetic/epigenetic changes involving growth-regulating genes, located on region 11p15, with an important genotype-phenotype correlation. Congenital adrenal hyperplasia (CAH) comprises a spectrum of autosomal recessive diseases presenting a variety of clinical manifestations due to a deficiency in one of the enzymes involved in cortisol secretion. Early diagnosis based on newborn screening prevents the adrenal crisis and early infant death. However, high 17-hydroxyprogesterone (17-OHP) levels can occur in newborns or premature infants without CAH, in situations of stress due to maternal or neonatal factors. Here, we report new cases of false-positive diagnosis of 21-hydroxylase deficiency during newborn screening - two girls and one boy with BWS. Methylation-specific multiplex ligation-dependent probe amplification revealed a gain of methylation in the H19 differentially methylated region. Notably, all three cases showed a complete normalization of biochemical changes, highlighting the transient nature of these hormonal findings that imitate the classical form of CAH. This report sheds light on a new cause of false-positive 21-hydroxylase deficiency diagnosis during newborn screening: Beckwith-Wiedemann syndrome.
RESUMEN
Androgenic insensitivity syndrome is the most common cause of disorders of sexual differentiation in 46,XY individuals. It results from alterations in the androgen receptor gene, leading to a frame of hormonal resistance, which may present clinically under 3 phenotypes: complete (CAIS), partial (PAIS) or mild (MAIS). The androgen receptor gene has 8 exons and 3 domains, and allelic variants in this gene occur in all domains and exons, regardless of phenotype, providing a poor genotype - phenotype correlation in this syndrome. Typically, laboratory diagnosis is made through elevated levels of LH and testosterone, with little or no virilization. Treatment depends on the phenotype and social sex of the individual. Open issues in the management of androgen insensitivity syndromes includes decisions on sex assignment, timing of gonadectomy, fertility, physcological outcomes and genetic counseling.
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Síndrome de Resistencia Androgénica/genética , Síndrome de Resistencia Androgénica/terapia , Síndrome de Resistencia Androgénica/fisiopatología , Femenino , Terapia de Reemplazo de Hormonas , Humanos , Masculino , FenotipoRESUMEN
17ß-hydroxysteroid dehydrogenase 3 deficiency consists of a defect in the last phase of steroidogenesis, in which androstenedione is converted into testosterone and estrone into estradiol. External genitalia range from female-like to atypical genitalia and most affected males are raised as females. Virilization in subjects with 17ß-HSD3 deficiency occurs at the time of puberty and several of them change to male social sex. In male social sex patients, testes can be safely maintained, as long as they are positioned inside the scrotum The phenotype of 46,XY DSD due to 17ß-HSD3 deficiency is extremely variable and clinically indistinguishable from other causes of 46,XY DSD such as partial androgen insensitivity syndrome and 5α-reductase 2 deficiency. Laboratory diagnosis is based on a low testosterone/androstenedione ratio due to high serum levels of androstenedione and low levels of testosterone. The disorder is caused by a homozygous or compound heterozygous mutations in the HSD17B3 gene that encodes the 17ß-HSD3 isoenzyme leading to an impairment of the conversion of 17-keto into 17-hydroxysteroids. Molecular genetic testing confirms the diagnosis and provides the orientation for genetic counseling. Our proposal in this article is to review the previously reported cases of 17ß-HSD3 deficiency adding our own cases.