A Novel Nonsense Mutation in RSPO4 Gene Underlies Autosomal Recessive Congenital Anonychia in a Pakistani Family


Address correspondence to Wasim Ahmad, Ph.D., Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan, or e-mail: wahmad@qau.edu.pk.


Abstract:  Congenital anonychia is an inherited autosomal recessive disorder characterized by complete absence of fingernails or toenails, or both. In the present study, we have described a consanguineous Pakistani family having a family member affected with congenital anonychia. Genotyping using polymorphic microsatellite markers showed linkage of the family to gene RSPO4 encoding R-spondin and mapped on human chromosome 20p13. Deoxyribonucleic acid sequence analysis of the gene identified a novel nonsense mutation (c.18C>A; p.Cys6X) in the affected family member.