ABSTRACT
PURPOSE: This study aimed to present the clinical features and gene mutation characteristics of a child with 46,XY disorders of sex development (DSD) caused by a novel heterozygous mutation in the NR5A1 gene to determine the potential association between this heterozygous mutation and the pathogenesis of 46,XY DSD. METHODS: We present the case of a Chinese child with ambiguous genitalia at birth but a normal adrenal gland. Targeted next-generation sequencing, comprising 163 candidate genes involved in sexual differentiation and development, was performed, followed by the functional evaluation of the novel NR5A1 mutation. RESULT: The patient had a novel heterozygous mutation in the NR5A1 gene, c.630delG (p.Y211Tfs*85). Results revealed that overexpression of p.Y211Tfs*85 impaired steroidogenic factor-1 (SF-1) protein synthesis. Immunofluorescence analysis revealed that both SF-1 wild-type and p.Y211Tfs*85 mutation proteins were localized in the cell nucleus. Furthermore, dual-luciferase reporter assay results revealed that the p.Y211Tfs*85 mutation could effectively downregulate the transcriptional activation of anti-Müllerian hormone and steroidogenic acute regulatory protein genes (P < 0.01). Additionally, the p.Y211Tfs*85 mutation changed three-dimensional conformation of SF-1, and three conformations could be constructed with the mutated amino acid sequences. Therefore, the novel frameshift mutation could result in decreased protein expression of SF-1. CONCLUSION: We described a novel mutation in NR5A1 and showed that it might affect protein structure, thereby seriously compromising the role of SF-1 in regulating gonadal development. The novel p.Y211Tfs*85 mutation in the NR5A1 gene enriches the boy of information available regarding the mutation spectrum of this gene in the Chinese population.
Subject(s)
Disorder of Sex Development, 46,XY/genetics , Genetic Predisposition to Disease , Steroidogenic Factor 1/genetics , Amino Acid Sequence/genetics , Child , China/epidemiology , Disorder of Sex Development, 46,XY/pathology , Female , Heterozygote , High-Throughput Nucleotide Sequencing , Humans , Male , MutationABSTRACT
AIMS: p21(Waf1/Cip1) is a cyclin-dependent kinase inhibitor that is pivotal in arresting cellular growth in terminal cell differentiation and apoptosis. Thus, the existence of natural variants of p21(Waf1/Cip1) could be linked to specific cancer. The purpose of this report was to identify a novel tri-allelic insertion/deletion (INDEL) polymorphism (rs4135235) involving a poly-T sequence in the promoter region of p21(Waf1/Cip1) gene and to explore its role in gastric cancer (GC). METHOD: A total of unrelated 676 subjects (376 GC patients; 300 cancer-free controls) were enrolled in the study, and genomic DNA was obtained from each subject for genotyping. PCR-directed sequencing technique was used to detect the genotypes of the polymorphism. TA cloning was used to confirm the existence of three alleles. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression analysis. RESULTS: Six genotypes (9T/9T, 10T/10T, 11T/11T, 9T/10T, 10T/11T, and 9T/11T) and three alleles (9Ts, 10Ts, and 11Ts) were identified among all study subjects. GC cases were different from the control group with over-representation of 9T/11T heterozygotes (19.7% vs. 12.3%) and under-representation of 10T/10T homozygotes (18.4% vs. 20.7%). Compared with those carrying 10T/10T, individuals with 9T/11T increased the susceptibility for GC (OR=1.797, 95%CI=1.065-3.031). CONCLUSION: Our findings confirmed the existence of a tri-allelic polymorphism in the promoter of p21(Waf1/Cip1). It has also shown the heterozygous genotype 9T/11T to be a potential risk factor for GC in the Chinese population.
