A Novel Look at Dosage-Sensitive Sex Locus Xp21.2 in a Case of 46,XY Partial Gonadal Dysgenesis without NR0B1 Duplication.

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.

NPHS1 gene mutations confirm congenital nephrotic syndrome in four Brazilian cases: A novel mutation is described.

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.

NPHS2 mutations account for only 15% of nephrotic syndrome cases.

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.

Patients with genital ambiguity referred without a sex definition: the relationship between clinical picture and defined sex of rearing.

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.

Two distinct WT1 mutations identified in patients and relatives with isolated nephrotic proteinuria.

Wilms' tumor type 1 gene (WT1) encodes a zinc-finger transcription factor that plays a key role during genitourinary development and in adult kidney. Mutations in exons 8 and 9 are associated with Denys-Drash Syndrome, whereas those occurring in the intron 9 donor splice site are associated with Frasier Syndrome. Familial cases of WT1 mutations are rare with only few cases described in the literature, whereas cases of WT1 mutations associated with isolated nephrotic proteinuria with or without focal segmental glomerular sclerosis (FSGS) are even rarer. Exons 8 and 9 of WT1 gene were analyzed in two non-related female patients and their parents. Patient 1, who presented with isolated nephrotic proteinuria and histologic pattern of FSGS, is heterozygous for the mutation c.1227+4C>T. This mutation was inherited from her mother, who had undergone kidney transplant due to FSGS. Patient 2 is heterozygous for the novel c.1178C>T transition inherited from her father. The putative effect of this nucleotide substitution on WT1 protein is p.Ser393Phe mutation located within the third zinc-finger domain. The patient and her father presented, respectively, isolated nephrotic proteinuria and chronic renal failure. These data highlight the importance of the inclusion of WT1 gene mutational analysis in patients with isolated nephrotic proteinuria, especially when similar conditions are referred to the family.

Can Non-Coding NR5A1 Gene Variants Explain Phenotypes of Disorders of Sex Development?

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.

Suggested Cutoff Point for Testosterone by Liquid Chromatography with Tandem Mass Spectrometry (LC-MS/MS) after Stimulation with Recombinant Human Chorionic Gonadotropin.

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.

Trends in Time Regarding Sex Assignment of Patients with Disorders of Sex Development: Experience of an Interdisciplinary Service.

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.

Novel deletion alleles carrying CYP21A1P/A2 chimeric genes in Brazilian patients with 21-hydroxylase deficiency.

BACKGROUND: Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is caused by deletions, large gene conversions or mutations in CYP21A2 gene. The human gene is located at 6p21.3 within a locus containing the genes for putative serine/threonine Kinase RP, complement C4, steroid 21-hydroxylase CYP21 tenascin TNX, normally, in a duplicated cluster known as RCCX module. The CYP21 extra copy is a pseudogene (CYP21A1P). In Brazil, 30-kb deletion forming monomodular alleles that carry chimeric CYP21A1P/A2 genes corresponds to ~9% of disease-causing alleles. Such alleles are considered to result from unequal crossovers within the bimodular C4/CYP21 locus. Depending on the localization of recombination breakpoint, different alleles can be generated conferring the locus high degree of allelic variability. The purpose of the study was to investigate the variability of deleted alleles in patients with 21-hydroxylase deficiency. METHODS: We used different techniques to investigate the variability of 30-kb deletion alleles in patients with 21-hydroxylase deficiency. Alleles were first selected after Southern blotting. The composition of CYP21A1P/A2 chimeric genes was investigated by ASO-PCR and MLPA analyses followed by sequencing to refine the location of recombination breakpoints. Twenty patients carrying at least one allele with C4/CYP21 30-kb deletion were included in the study. RESULTS: An allele carrying a CYP21A1P/A2 chimeric gene was found unusually associated to a C4B/C4A Taq I 6.4-kb fragment, generally associated to C4B and CYP21A1P deletions. A novel haplotype bearing both p.P34L and p.H62L, novel and rare mutations, respectively, was identified in exon 1, however p.P30L, the most frequent pseudogene-derived mutation in this exon, was absent. Four unrelated patients showed this haplotype. Absence of p.P34L in CYP21A1P of normal controls indicated that it is not derived from pseudogene. In addition, the combination of different approaches revealed nine haplotypes for deleted 21-hydroxylase deficiency alleles. CONCLUSIONS: This study demonstrated high allelic variability for 30-kb deletion in patients with 21-hydroxylase deficiency indicating that a founder effect might be improbable for most monomodular alleles carrying CYP21A1P/A2 chimeric genes in Brazil.

Association between Down Syndrome and Disorders of Sex Development: Report of Three Cases and Review of 188 Cases in the Literature.

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.

Why pediatricians need to know the disorders of sex development: experience of 709 cases in a specialized service.

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.

PIP4KIIA and beta-globin: transcripts differentially expressed in reticulocytes and associated with high levels of Hb H in two siblings with Hb H disease.

We are reporting here the results of differential gene expression experiments comparing two siblings, a 21-yr-old male and a 19-yr-old female, with the same alpha-thalassemia genotype (-alpha(3.7)/(--SEA)) and quite different levels of Hb H in the peripheral blood (18.7 and 5%, respectively). By using mRNA differential-display reverse-transcription-PCR and suppression subtractive hybridization, two main transcripts were selected in both procedures and validated by qRT-PCR, one corresponding to the phosphatidylinositol phosphate 4-kinase type II-alpha (PIP4KIIA) gene and the other to the beta-globin gene, both over expressed in the patient with the higher percentage of Hb H. Type II PIP kinases produce phosphatidylinositol 4,5 biphosphate, a critical and pleiotropic regulatory molecule involved in diverse cellular activities, including gene expression. Our results suggest that PIP4KIIA may be one of the factors related to the regulation of the beta-globin gene expression and the different levels of Hb H in alpha-thalassemic patients.

Clinical Findings and Follow-Up of 46,XY and 45,X/46,XY Testicular Dysgenesis.

Historically, the terms partial (PGD) and mixed gonadal dysgenesis (MGD) have been used to describe incomplete testicular differentiation in individuals with 46,XY or 45,X/46,XY karyotypes, respectively. However, it is currently unclear to what extent clinical features actually differ between these individuals. The aim of this study was to compare clinical, laboratory, and histological findings in these 2 groups. Patients with testicular dysgenesis seen in our service between 1989 and 2013 were selected. Sixty-one patients met the inclusion criteria. Individuals with 46,XY and 45,X/46,XY karyotypes were compared regarding genital features, gonadal histology and function, growth, and associated conditions. Twenty-five had mosaicism with a 45,X cell line (MGD), while a 46,XY karyotype (PGD) was found in 36 cases belonging to 32 families. Mutations in NR5A1, WT1, and SRY genes associated with testicular dysgenesis were found in 12 families. There were no significant differences regarding parental consanguinity, degree of external androgenization, gonadal location, histology, and function, and associated conditions. However, in the MGD group, the presence of a uterus, lower birth weight and length, and short stature were more often observed. Therefore, the use of histological features to classify PDG and MGD should be abandoned and replaced by classification based on karyotype.

21-hydroxylase deficiency transiently mimicking combined 21- and 11beta-hydroxylase deficiency.

21-Hydroxylase deficiency (21OHD) is the commonest form of congenital adrenal hyperplasia, while 11betaOHD represents 5% of cases. Although both result from mutations in distinct genes, cases of 'apparent' combined 21OHD and 11betaOHD (AC21,11OHD) have been occasionally reported. A 6 year-old girl, born with ambiguous genitalia and salt-loss, had serum elevations (ng/dl) of androstenedione (>1,000), 17-hydroxyprogesterone (17OHP; 38,483), 21-deoxycortisol (21DF; 23,338), and 11-deoxycortisol (S; 4,928), suggesting AC21,11OHD. CYP21A and CYP11B1 genotyping identified mutations only in the former. On follow-up, serum S became normal but 17OHP and 21DF were still elevated. ACTH stimulation disclosed elevated levels of 17OHP and 21DF, but unresponsive S and undetectable deoxycorticosterone. The hormonal pattern initially suggested AC21,11OHD, but subsequent normalization of S showed transient 11-hydroxylase inhibition. This may have occurred by enzyme or co-enzyme immaturity or functional discrepancy, but also by selective inhibition of 11betaOH by excess intra-adrenal concentration of androgens, acting as pseudo-substrates for this enzyme.

A Search for Disorders of Sex Development among Infertile Men.

A retrospective cross-sectional study was performed in a DSD clinic at a tertiary service (University Hospital) to estimate the frequency of disorders of sex development (DSD) among men who seek medical care because of infertility. The sample included 84 men >20 years of age referred from 2010-2017 due to oligozoospermia or nonobstructive azoospermia of unknown etiology. Twelve cases (14%) were diagnosed as DSD, including Klinefelter Syndrome, 46,XX testicular DSD, and mild androgen insensitivity syndrome. Y chromosome microdeletions were detected in 2 patients. Among the remaining 70 cases there were patients with chromosome abnormalities which are not included in the DSD classification as well as rare NR5A1 variants of uncertain significance and hypergonadotropic hypogonadism and microorchidism in 46,XY subjects. In conclusion, the frequency of DSD in this study was 14%, consisting mainly of sex chromosome abnormalities but also 46,XX and 46,XY DSD. However, this figure may increase as further investigations are conducted in idiopathic cases with signs of primary testicular failure, which may present partial gonadal dysgenesis.

NPHS2 Mutations: A Closer Look to Latin American Countries.

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.

WT1 Haploinsufficiency Supports Milder Renal Manifestation in Two Patients with Denys-Drash Syndrome.

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.

Functional Impact of Novel Androgen Receptor Mutations on the Clinical Manifestation of Androgen Insensitivity Syndrome.

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.

A Novel Homozygous Missense FSHR Variant Associated with Hypergonadotropic Hypogonadism in Two Siblings from a Brazilian Family.

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.