Department of Endocrinology, NHC Key Laboratory of Endocrinology (Peking Union Medical College Hospital), State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
Orphanet J Rare Dis. 2021 Aug 30;16(1):370. doi: 10.1186/s13023-021-02002-0.
To identify the pathogenic mechanism of the c.244G>T mutation in NR5A1 gene found in a Chinese patient with 46, XY disorders of sex development (DSD).
Genomic DNA was extracted from a Chinese 46, XY DSD patient. Targeted next-generation and Sanger sequencing were performed to investigate and validate the gene mutation causing 46, XY DSD, respectively. In silico tools were used to predict the pathogenicity of the variant. Dual luciferase reporter gene assay and minigene splicing reporter assay were used to identify the pathogenicity of the variant.
A novel heterozygous variant, c.244G>T (p.Ala82Ser), in NR5A1 gene was detected in the 46, XY DSD patient. Four of five silico tools predicting pathogenicity of missense variants indicated that the variant was pathogenic. However, in vitro functional study showed that p.Ala82Ser did not affect the transcriptional activity of NR5A1. In silico tools predicting the potential splicing loci revealed that c.244G>T led to aberrant splicing of NR5A1 RNA. Minigene splicing reporter assay confirmed that c.244G>T resulted in the deletion of exon2 or deletion of 19 nucleotides in 3' end of exon2.
Mutation of c.244G>T in NR5A1 results in 46, XY DSD by inducing abnormal splicing of NR5A1 RNA instead of amino acid substitution of NR5A1.
鉴定在中国性发育障碍（DSD）46,XY 患者中发现的 NR5A1 基因 c.244G>T 突变的致病机制。
从一名中国 46,XY DSD 患者中提取基因组 DNA。分别采用靶向下一代测序和 Sanger 测序来调查和验证导致 46,XY DSD 的基因突变。使用计算机工具预测变异的致病性。双荧光素酶报告基因检测和迷你基因剪接报告基因检测用于鉴定变异的致病性。
在该 46,XY DSD 患者中检测到 NR5A1 基因中的一种新的杂合变异 c.244G>T（p.Ala82Ser）。五种预测错义变异致病性的计算机工具中的四种表明该变异具有致病性。然而，体外功能研究表明 p.Ala82Ser 不影响 NR5A1 的转录活性。预测潜在剪接位点的计算机工具表明 c.244G>T 导致 NR5A1 RNA 的异常剪接。迷你基因剪接报告基因检测证实 c.244G>T 导致外显子 2 的缺失或外显子 2 3'端的 19 个核苷酸缺失。
NR5A1 基因中 c.244G>T 的突变通过诱导 NR5A1 RNA 的异常剪接而不是 NR5A1 氨基酸取代导致 46,XY DSD。
