A novel homozygous missense mutation in WNT10B in familial split-hand/foot malformation

Split-hand/foot malformation (SHFM) is a rare limb developmental malformation, characterized by variable degree of median clefts of hands and feet due to the absence of central rays of extremities. To date, six different forms of SHFM have been described. Four of these SHFM1, SHFM3, SHFM4 and SHFM5 show autosomal dominant, SHFM6 autosomal recessive and SHFM2 X-linked pattern of inheritance. In this study a large consanguineous Pakistani family, with autosomal recessive SHFM, appeared in the last two generations, was investigated. In total 15 individuals including 9 males and 6 females were affected with the syndrome. Affected members of the family exhibited SHFM phenotype with involvement of hands and feet. Most of the affected members showed syndactyly/polydactyly in hands and feet, dysplastic hand, aplasia of radial ray of hand and cleft foot. Investigating linkage to known autosomal SHFM loci mapped the family to SHFM6 locus on chromosome 12p11.1-q13.13. Mutation screening of the gene WNT10B revealed a novel sequence variant (c.986C>G, p.Thr329Arg) in all affected individuals who were studied. This is the third mutation reported in gene WNT10B causing autosomal recessive SHFM syndrome.