WISP3 mutational analysis in Indian patients diagnosed with progressive pseudorheumatoid dysplasia and report of a novel mutation at p.Y198∗

Abstract

Objectives: To determine the pattern of mutations of the WISP3 gene in clinically identified progressive pseudorheumatoid dysplasia (PPD) in an Indian population. Patients and Methods: A total of 15 patients with clinical features of PPD were enrolled in this study. Genomic DNA was isolated and polymerase chain reaction performed to amplify the WISP3 gene. Screening for mutations was done by conformation-sensitive gel electrophoresis, beginning with the fifth exon and subsequently proceeding to the remaining exons. Sanger sequencing was performed for both forward and reverse strands to confirm the mutations. Results: In all, two of the 15 patients had compound heterozygous mutations: one a nonsense mutation c.156C>A (p.C52∗) in exon 2, and the other a missense mutation c.677G>T (p.G226V) in exon 4. All others were homozygous, with three bearing a nonsense mutation c.156C>A (p.C52∗) in exon 2, three a missense mutation c.233G>A (p.C78Y) in exon 2, five a missense mutation c.1010G>A (p.C337Y) in exon 5, one a nonsense mutation c.348C>A (p.Y116∗) in exon 3, and one with a novel deletion mutation c.593-597delATAGA (p.Y198∗) in exon 4. Conclusion: We identified a novel mutation c.593-597delATAGA (p.Y198∗) in the fourth exon of the WISP3 gene. We also confirmed c.1010G>A as one of the common mutations in an Indian population with progressive pseudorheumatoid dysplasia.