Homozygous WNT10b mutation and complex inheritance in Split-Hand/Foot Malformation.
Split-Hand/Foot Malformation (SHFM) is a complex limb malformation affecting the central rays of the autopod. We studied a large consanguineous kindred afflicted with autosomal recessive SHFM. Twelve affected members had central feet reductions with or without hand involvement while the remaining one had the mildest phenotype and atypical SHFM. We identified by homozygosity mapping a novel SHFM locus at 12q13.11-q13 with a maximum multipoint lod score of 5.47 and by subsequent candidate gene approach a homozygous missense WNT10b mutation (p.R332W) in all affected individuals but the atypical case plus in an asymptomatic female. We propose that either a second locus contributes to the manifestation of SHFM phenotype or a suppressor locus prevented trait manifestation in the non-penetrant female. We also investigated linkage to the five known SHFM loci. Four of the loci were excluded, while in TP63 [tumor protein p63 (SHFM4)], the only known gene responsible for SHFM, we detected in most affected subjects a rare insertion variant (rs34201045) at the alternate promoter used for transcription of the N-terminal-truncated p63 isotype. This is the first reported WNT10b mutation on the pathogenesis of limb development and recessive mutation in SHFM.
Department of Molecular Biology and Genetics, Boaziçi University, Istanbul 34342, Turkey. ugursibe@boun.edu.tr
Sibel Aylin
SA
Ugur
Aslihan
A
Tolun
D000595:Amino Acid Sequence; D000818:Animals; D002881:Chromosomes, Human, Pair 12; D004252:DNA Mutational Analysis; D005260:Female; D005532:Foot Deformities, Congenital / Q000235:genetics; D006228:Hand Deformities, Congenital / Q000235:genetics; D006720:Homozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D051153:Wnt Proteins / Q000737:chemistry / Q000235:genetics*
D011518:Proto-Oncogene Proteins; C491119:WNT10B protein, human; D051153:Wnt Proteins