Spectrum of Pathogenic Variants in SRD5A2 in Indian Children with 46,XY Disorders of Sex Development and Clinically Suspected Steroid 5α-Reductase 2 Deficiency

2019 ◽  
Vol 13 (5-6) ◽  
pp. 228-239
Author(s):  
Anil Kumar ◽  
Rajni Sharma ◽  
Mohammed Faruq ◽  
Varun Suroliya ◽  
Manoj Kumar ◽  
...  

The aim of this study was to assess the prevalence of pathogenic variants in the <i>SRD5A2</i> gene in children with 46,XY disorders of sex development (DSD) with normal to high serum testosterone levels and absence of Müllerian structures on imaging and to evaluate the genotype-phenotype correlation. Seventy-five patients with 46,XY DSD and probable clinical diagnosis of 5α-reductase 2 deficiency or androgen insensitivity syndrome were enrolled. Genetic analysis was done for pathogenic variants in <i>SRD5A2</i>, and the genotype-phenotype correlation was studied. As a result, 10 pathogenic or likely pathogenic biallelic variants in <i>SRD5A2, </i>either homozygous or compound heterozygous, were identified in 25 of 75 (33.3%) patients. The hCG stimulated testosterone: dihydrotestosterone (T:DHT) ratio was elevated in all patients with pathogenic variants in <i>SRD5A2</i> and in nearly 90% of those without pathogenic variants in <i>SRD5A2</i> in whom this was assessed. The missense pathogenic variant p.R246Q was a hotspot. One novel pathogenic variant p.Y178*, and a variant p.F194I, not previously reported in patients with 5α-reductase 2 deficiency, were identified. The missense variant p.F194I was predicted as deleterious and damaging by in silico analysis and as likely to reduce the enzyme activity by protein modeling. In conclusion, pathogenic variants in <i>SRD5A2 </i>can be detected in a wide spectrum of Indian patients with 46,XY DSD. Molecular genetic analysis should be considered as a first-line test as the T:DHT ratio lacks specificity and a hotspot variant is present in a vast majority.

2020 ◽  
Vol 33 (1) ◽  
pp. 79-88 ◽  
Author(s):  
Anil Kumar ◽  
Vandana Jain ◽  
Madhumita Roy Chowdhury ◽  
Manoj Kumar ◽  
Punit Kaur ◽  
...  

AbstractBackgroundOur objective was to estimate the prevalence of pathogenic/likely pathogenic variants in the SHOX, GHR, and IGFALS genes among Indian children with idiopathic short stature (ISS), and assess the genotype-phenotype correlation.MethodsWe recruited 61 children with short stature, who were born appropriate for gestational age, had no obvious dysmorphism or disproportion, and in whom step-wise investigative work-up (including provocative growth hormone test) was normal. Multiplex ligation-dependent probe amplification was undertaken for identifying deletions/duplications in the SHOX gene. Bidirectional sequencing was performed for identifying variants in the SHOX and GHR genes in all, and for the IGFALS gene in those with serum insulin-like growth factor-1 (IGF-1) <−1 standard deviation. The genotype-phenotype correlation was studied.ResultsFour children (6.5%) had pathogenic heterozygous variants in the SHOX gene, with one child each having duplication of exon 5, splice site point variant c.278-1G > C in exon 3, partial deletion and complete deletion. None of the patients had pathogenic variants in the GHR gene. Of the 39 patients in whom the IGFALS gene was sequenced, novel heterozygous likely pathogenic variants were found in two children. One had the frameshift variant c.764_765insT, p.A265Gfs*114. The second had the missense variant c.1793G > A, p.R598H predicted by MutationTaster as ‘disease causing’, and indicated by the protein-modelling study as having compromised binding with IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) due to altered conformation of the interacting loop.ConclusionsPathogenic variants in the SHOX and IGFALS genes account for a significant proportion of Indian children with ISS. Further molecular studies using next generation sequencing are needed to gain insight into pathophysiological mechanisms and effective treatment strategies for ISS.


2021 ◽  
Author(s):  
Khouloud Rjiba ◽  
Hedia Ayech ◽  
Wafa Slimani ◽  
Olfa KRAIEM ◽  
Afef Jelloul ◽  
...  

Abstract Background: Wolf-Hirschhorn (WHS) is a set of congenital physical anomalies and mental retardation associated with a partial deletion of the short arm of chromosome 4.To establish a genotype-phenotype correlation; we carried out a molecular cytogenetic analysis on two Tunisian WHS patients. Patient 1was a boy of one-year-old presented typical WHS phenotype while patient 2, is a boy of two days presented an hypospadias, a micropenis and cryptorchidie in addition to the typical WHS phenotype. Both the comparative genomic hybridization (CGH array) and Fluorescence in Situ Hybridization (FISH) techniques were used.Results: Results of the analysis showed that patient 2 had a greater deletion size (4,8Mb) of chromosome 4 than patient 1 (3, 4 Mb). Here, we notice that the larger the deletion, the more genes are likely to be involved, and the more severe the phenotype is likely to be. If we analyze the uncommon deleted region between patient1 and patient 2 we found that the Muscle Segment Homeobox (MSX1) gene is included in this region. MSX1 is a critical transcriptional repressor factor, expressed in the ventral side of the developing anterior pituitary and implicated in gonadotrope differentiation. Msx acts as a negative regulatory pituitary development by repressing the gonadotropin releasing hormone (GnRH) genes during embryogenesis. We hypothesized that the deletion of MSX1 in our patient may deregulate the androgen synthesis. Conclusion: Based on the MSX1 gene function, its absence might be indirectly responsible for the hypospadias phenotype by contributing to the spatiotemporal regulation of GnRH transcription during development.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Khouloud Rjiba ◽  
Hédia Ayech ◽  
Olfa Kraiem ◽  
Wafa Slimani ◽  
Afef Jelloul ◽  
...  

AbstractBackgroundWolf–Hirschhorn (WHS) is a set of congenital physical anomalies and mental retardation associated with a partial deletion of the short arm of chromosome 4. To establish a genotype–phenotype correlation; we carried out a molecular cytogenetic analysis on two Tunisian WHS patients. Patient 1 was a boy of 1-year-old, presented a typical WHS phenotype while patient 2, is a boy of 2 days presented an hypospadias, a micropenis and a cryptorchidie in addition to the typical WHS phenotype. Both the array comparative genomic hybridization and fluorescence in situ hybridization techniques were used.ResultsResults of the analysis showed that patient 2 had a greater deletion size (4.8 Mb) of chromosome 4 than patient 1 (3.4 Mb). Here, we notice that the larger the deletion, the more genes are likely to be involved, and the more severe the phenotype is likely to be. If we analyze the uncommon deleted region between patient1 and patient 2 we found that the Muscle Segment Homeobox (MSX1) gene is included in this region.MSX1is a critical transcriptional repressor factor, expressed in the ventral side of the developing anterior pituitary and implicated in gonadotrope differentiation.Msx1acts as a negative regulatory pituitary development by repressing the gonadotropin releasing hormone (GnRH) genes during embryogenesis. We hypothesized that the deletion ofMSX1in our patient may deregulate the androgen synthesis.ConclusionBased on theMSX1gene function, its absence might be indirectly responsible for the hypospadias phenotype by contributing to the spatiotemporal regulation ofGnRHtranscription during development.


2021 ◽  
Author(s):  
khouloud Rjiba ◽  
Hedia Ayech ◽  
wafa Slimani ◽  
Olfa KRAIEM ◽  
Afef Jelloul ◽  
...  

Abstract Background: Wolf-Hirschhorn (WHS) is a set of congenital physical anomalies and mental retardation associated with a partial deletion of the short arm of chromosome 4.To establish a genotype-phenotype correlation; we carried out a molecular cytogenetic analysis on two Tunisian WHS patients. Patient 1 was a boy of one-year-old, presented a typical WHS phenotype while patient 2, is a boy of two days presented an hypospadias, a micropenis and a cryptorchidie in addition to the typical WHS phenotype. Both the array comparative genomic hybridization (array CGH) and Fluorescence in Situ Hybridization (FISH) techniques were used.Results: Results of the analysis showed that patient 2 had a greater deletion size (4,8Mb) of chromosome 4 than patient 1 (3,4 Mb). Here, we notice that the larger the deletion, the more genes are likely to be involved, and the more severe the phenotype is likely to be. If we analyze the uncommon deleted region between patient1 and patient 2 we found that the Muscle Segment Homeobox (MSX1) gene is included in this region. MSX1 is a critical transcriptional repressor factor, expressed in the ventral side of the developing anterior pituitary and implicated in gonadotrope differentiation. Msx1 acts as a negative regulatory pituitary development by repressing the gonadotropin releasing hormone (GnRH) genes during embryogenesis. We hypothesized that the deletion of MSX1 in our patient may deregulate the androgen synthesis. Conclusion: Based on the MSX1 gene function, its absence might be indirectly responsible for the hypospadias phenotype by contributing to the spatiotemporal regulation of GnRH transcription during development.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dustin B. Miller ◽  
Stephen R. Piccolo

Compound heterozygous (CH) variants occur when two recessive alleles are inherited and the variants are located at different loci within the same gene in a given individual. CH variants are important contributors to many different types of recessively inherited diseases. However, many studies overlook CH variants because identification of this type of variant requires knowing the parent of origin for each nucleotide. Using computational methods, haplotypes can be inferred using a process called “phasing,” which estimates the chromosomal origin of most nucleotides. In this paper, we used germline, phased, whole-genome sequencing (WGS) data to identify CH variants across seven pediatric diseases (adolescent idiopathic scoliosis: n = 16, congenital heart defects: n = 709, disorders of sex development: n = 79, ewing sarcoma: n = 287, neuroblastoma: n = 259, orofacial cleft: n = 107, and syndromic cranial dysinnervation: n = 172), available as parent-child trios in the Gabriella Miller Kids First Data Resource Center. Relatively little is understood about the genetic underpinnings of these diseases. We classified CH variants as “potentially damaging” based on minor allele frequencies (MAF), Combined Annotation Dependent Depletion scores, variant impact on transcription or translation, and gene-level frequencies in the disease group compared to a healthy population. For comparison, we also identified homozygous alternate (HA) variants, which affect both gene copies at a single locus; HA variants represent an alternative mechanism of recessive disease development and do not require phasing. Across all diseases, 2.6% of the samples had a potentially damaging CH variant and 16.2% had a potentially damaging HA variant. Of these samples with potentially damaging variants, the average number of genes per sample was 1 with a CH variant and 1.25 with a HA variant. Across all samples, 5.1 genes per disease had a CH variant, while 35.6 genes per disease had a HA variant; on average, only 4.3% of these variants affected common genes. Therefore, when seeking to identify potentially damaging variants of a putatively recessive disease, CH variants should be considered as potential contributors to disease development. If CH variants are excluded from analysis, important candidate genes may be overlooked.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kodai Abe ◽  
Arisa Ueki ◽  
Yusaku Urakawa ◽  
Minoru Kitago ◽  
Tomoko Yoshihama ◽  
...  

Abstract Background Family history is one of the risk factors for pancreatic cancer. It is suggested that patients with pancreatic cancer who have a familial history harbor germline pathogenic variants of BRCA1 and/or BRCA2 (BRCA1/2), PALB2, or ATM. Recently, some germline variants of familial pancreatic cancers (FPCs), including PALB2, have been detected. Several countries, including Japan, perform screening workups and genetic analysis for pancreatic cancers. We have been carrying out active surveillance for FPC through epidemiological surveys, imaging analyses, and genetic analysis. Case presentation Here, we present the case of a female patient harboring pathogenic variants of PALB2 and NBN, with a family history of multiple pancreatic cancer in her younger brother, her aunt, and her father. Moreover, her father harbored a PALB2 pathogenic variant and her daughter harbored the same NBN pathogenic variant. Given the PALB2 and NBN variants, we designed surveillance strategies for the pancreas, breast, and ovary. Conclusions Further studies are required to develop strategies for managing FPCs to facilitate prompt diagnosis before their progression.


2021 ◽  
pp. 1-9
Author(s):  
Maria T.M. Ferrari ◽  
Andreia Watanabe ◽  
Thatiane E. da Silva ◽  
Nathalia L. Gomes ◽  
Rafael L. Batista ◽  
...  

Wilms’ tumor suppressor gene 1 (<i>WT1</i>) plays an essential role in urogenital and kidney development. Heterozygous germline pathogenic allelic variants of <i>WT1</i> 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 <i>WT1</i> disorders has been frequently observed. New <i>WT1</i> 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 <i>WT1</i> 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 <i>WT1</i> between exons 9 and 10. Two pathogenic missense <i>WT1</i> variants were identified in two 46,XY individuals with Wilms’ tumors; both patients were &#x3c;1 year of age at the time of diagnosis. A novel <i>WT1</i> variant<i>,</i> 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 <i>WT1</i> 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.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Nanis S. Marzuki ◽  
Firman P. Idris ◽  
Hannie D. Kartapradja ◽  
Alida R. Harahap ◽  
Jose R. L. Batubara

The 5-alpha-reductase type 2 deficiency (5ARD2) is an autosomal recessive condition associated with impairment in the conversion of testosterone to dihydrotestosterone. This condition leads to undervirilisation in 46,XY individuals. To date, there have been more than 100 variations identified in the gene responsible for 5ARD2 development (steroid 5-alpha-reductase 2, SRD5A2). However, few studies have examined the molecular characterisation of Indonesian 5ARD2 cases. In the current study, we analysed 37 subjects diagnosed with 46,XY DSD (disorders of sex development) with confirmed variations in the SRD5A2 gene. We examined results from testosterone/dihydrotestosterone (T/DHT) and urinary etiocholanolone/androsterone (Et/An) ratios, as well as from molecular and clinical analyses. Twelve variants in the SRD5A2 gene were identified, and 6 of which were novel, namely, c.34–38delGinsCCAGC, p.Arg50His, p.Tyr136∗, p.Gly191Arg, p.Phe194Ile, and p.Ile253Val variants. Moreover, we determined that 20 individuals contained harmful mutations, while the remaining 17 variants were benign. Those containing harmful mutations exhibited more severe phenotypes with median external genitalia masculinisation scores (EMS) of 3 (1.5–9) and were more likely to be diagnosed at a later age, reared as female, and virilised at pubertal age. In addition, the respective sensitivities for detecting severe 5ARD2 cases using T/DHT (cutoff: 10) and urinary Et/An ratios (cutoff: 0.95) were 85% and 90%, whereas mild cases were only identified with 64.7% and 47.1% sensitivity, respectively. Although we were unable to identify clear correlations between genotypic and phenotypic characteristics in this study, we clearly showed that individuals who were homozygous or compound heterozygous for any of the harmful mutations were more likely to exhibit classic 5ARD2 phenotypes, lower EMS, female assignment at birth, and virilisation during puberty. These results serve to inform the development of improved clinical and molecular 5ARD2 diagnostic approaches, specifically in Indonesian patients.


2020 ◽  
Vol 139 (11) ◽  
pp. 1455-1470
Author(s):  
Maëva Elzaiat ◽  
Delphine Flatters ◽  
Diana Carolina Sierra-Díaz ◽  
Berangère Legois ◽  
Paul Laissue ◽  
...  

Author(s):  
Nasir A.M. Al-Jurayyan ◽  
Sharifah D.A. Al Issa ◽  
Abdulrahman M.H. Al Nemri ◽  
Hessah M.N. Al Otaibi ◽  
Amir M.I. Babiker

AbstractThe term disorders of sex development (DSD) includes congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. The spectrum of the 46XY (DSD) is so broad. In this study, we reviewed the clinical spectrum of a cohort of patients with 46XY DSD in a tertiary institute in the Middle East over two decades.To define the clinical spectrum of 46XY DSD in a major teaching hospital, Riyadh, Saudi Arabia.This is a retrospective, case series hospital-based study. The case notes, laboratory investigations, and imaging studies were reviewed for patients with 46XY DSD over a 20 years period (1989–2010) at King Khalid University Hospital, Riyadh, Saudi Arabia. Molecular genetics were not available in all patients.During the period under review; a total of 56 patients were seen with 46XY DSD due to variable etiologies. Androgen insensitivity syndromes (AIS) and 5-α-reductase deficiency were among the commonest (44.6%), with multiple siblings involvement within the family. Of these, 16 patients were showing variable degrees of insensitivity ranging between complete (n=5, 31.2%) and partial (n=11, 68.8%) insensitivity, whereas in nine patients the diagnosis of 5-α-reductase deficiency was entertained based on hormonal studies. Of interest to see was a high number of patients (n=14, 25%) either with a localized congenital anomalies such as the cloacal anomalies or generalized congenital malformations following the pattern of certain syndromes.A wide spectrum of causes were noted. Androgen insensitivity syndrome was the commonest. In Saudi Arabia, where consanguineous mating is high, 5-α-reductase is also a common cause of 46XY DSD.


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