Dataset Information

Nonsense-associated altered splicing of MAP3K1 in two siblings with 46,XY disorders of sex development.

ABSTRACT: Although splicing errors due to single nucleotide variants represent a common cause of monogenic disorders, only a few variants have been shown to create new splice sites in exons. Here, we report an MAP3K1 splice variant identified in two siblings with 46,XY disorder of sex development. The patients carried a maternally derived c.2254C>T variant. The variant was initially recognized as a nonsense substitution leading to nonsense-mediated mRNA decay (p.Gln752Ter); however, RT-PCR for lymphoblastoid cell lines showed that this variant created a new splice donor site and caused 39 amino acid deletion (p.Gln752_Arg790del). All transcripts from the variant allele appeared to undergo altered splicing. The two patients exhibited undermasculinized genitalia with and without hypergonadotropism. Testosterone enanthate injections and dihydrotestosterone ointment applications yielded only slight increase in their penile length. Dihydrotestosterone-induced APOD transactivation was less significant in patients' genital skin fibroblasts compared with that in control samples. This study provides an example of nonsense-associated altered splicing, in which a highly potent exonic splice site was created. Furthermore, our data, in conjunction with the previous data indicating the association between MAP3K1 and androgen receptor signaling, imply that the combination of testicular dysgenesis and androgen insensitivity may be a unique phenotype of MAP3K1 abnormalities.

SUBMITTER: Igarashi M

PROVIDER: S-EPMC7567082 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Nonsense-associated altered splicing of MAP3K1 in two siblings with 46,XY disorders of sex development.

Igarashi Maki M Masunaga Yohei Y Hasegawa Yuichi Y Kinjo Kenichi K Miyado Mami M Saitsu Hirotomo H Kato-Fukui Yuko Y Horikawa Reiko R Okubo Yomiko Y Ogata Tsutomu T Fukami Maki M

Scientific reports 20201015 1

Although splicing errors due to single nucleotide variants represent a common cause of monogenic disorders, only a few variants have been shown to create new splice sites in exons. Here, we report an MAP3K1 splice variant identified in two siblings with 46,XY disorder of sex development. The patients carried a maternally derived c.2254C>T variant. The variant was initially recognized as a nonsense substitution leading to nonsense-mediated mRNA decay (p.Gln752Ter); however, RT-PCR for lymphoblast ...[more]

PMID: 33060765

Similar Datasets

Project description:Background: 46,XY disorders/differences of sex development (46,XY DSD) are congenital conditions that result from abnormal gonadal development (gonadal dysgenesis) or abnormalities in androgen synthesis or action. During early embryonic development, several genes are involved in regulating the initiation and maintenance of testicular or ovarian-specific pathways. Recent reports have shown that MAP3K1 genes mediate the development of the 46,XY DSD, which present as complete or partial gonadal dysgenesis. Previous functional studies have demonstrated that some MAP3K1 variants result in the gain of protein function. However, data on possible mechanisms of MAP3K1 genes in modulating protein functions remain scant. Methods: This study identified a Han Chinese family with the 46,XY DSD. To assess the history and clinical manifestations for the 46,XY DSD patients, the physical, operational, ultra-sonographical, pathological, and other examinations were performed for family members. Variant analysis was conducted using both trio whole-exome sequencing (trio WES) and Sanger sequencing. On the other hand, we generated transiently transfected testicular teratoma cells (NT2/D1) and ovary-derived granular cells (KGN), with mutant or wild-type MAP3K1 gene. We then performed functional assays such as determination of steady-state levels of gender related factors, protein interaction and luciferase assay system. Results: Two affected siblings were diagnosed with 46,XY DSD. Our analysis showed a missense c.556A > G/p.R186G variant in the MAP3K1 gene. Functional assays demonstrated that the MAP3K1R186G variant was associated with significantly decreased affinity to ubiquitin (Ub; 43-49%) and increased affinity to RhoA, which was 3.19 ± 0.18 fold, compared to MAP3K1. The MAP3K1R186G led to hyperphosphorylation of p38 and GSK3β, and promoted hyperactivation of the Wnt4/β-catenin signaling. In addition, there was increased recruitment of β-catenin into the nucleus, which enhanced the expression of pro-ovarian transcription factor FOXL2 gene, thus contributing to the 46,XY DSD. Conclusion: Our study identified a missense MAP3K1 variant associated with 46,XY DSD. We demonstrated that MAP3K1R186G variant enhances binding to the RhoA and improves its own stability, resulting in the activation of the Wnt4/β-catenin/FOXL2 pathway. Taken together, these findings provide novel insights into the molecular mechanisms of 46,XY DSD and promotes better clinical evaluation.

Project description:BackgroundSteroidogenic factor 1 (SF-1, NR5A1) is a key transcriptional regulator of many genes involved in the hypothalamic-pituitary-gonadal axis and mutations in NR5A1 can result in 46,XY disorders of sex development (DSD). Patients with this condition typically present with ambiguous genitalia, partial gonadal dysgenesis, and absent/rudimentary Müllerian structures. In these cases, testosterone is usually low in early infancy, indicating significantly impaired androgen synthesis. Further, Sertoli cell dysfunction is seen (low inhibin B, anti-Müllerian hormone). However, gonadal function at puberty in patients with NR5A1 mutations is unknown.Subjects and methodsClinical assessment, endocrine evaluation, and genetic analysis were performed in one female and one male with 46,XY DSD who showed spontaneous virilization during puberty. The female patient presented at adolescence with clitoral hypertrophy, whereas the male patient presented at birth with severe hypospadias and entered puberty spontaneously. Molecular analysis of NR5A1 was performed followed by in vitro functional analysis of the two novel mutations detected.ResultsTestosterone levels were normal during puberty in both patients. Analysis of NR5A1 revealed two novel heterozygous missense mutations in the ligand-binding domain of SF-1 (patient 1: p.L376F; patient 2: p.G328V). The mutant proteins showed reduced transactivation of the CYP11A promoter in vitro.ConclusionPatients with 46,XY DSD and NR5A1 mutations can produce sufficient testosterone for spontaneous virilization during puberty. Phenotypic females (46,XY) with NR5A1 mutations can present with clitoromegaly at puberty, a phenotype similar to other partial defects of androgen synthesis or action. Testosterone production in 46,XY males with NR5A1 mutations can be sufficient for virilization at puberty. As progressive gonadal dysgenesis is likely, gonadal function should be monitored in adolescence and adulthood, and early sperm cryopreservation considered in male patients if possible.

Dataset Information

Nonsense-associated altered splicing of MAP3K1 in two siblings with 46,XY disorders of sex development.

Publications

Nonsense-associated altered splicing of MAP3K1 in two siblings with 46,XY disorders of sex development.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets