Ef. Percin et al., MESOAXIAL COMPLETE SYNDACTYLY AND SYNOSTOSIS WITH HYPOPLASTIC THUMBS - AN UNUSUAL COMBINATION OR HOMOZYGOUS EXPRESSION OF SYNDACTYLY TYPE-I, Journal of Medical Genetics, 35(10), 1998, pp. 868-874
Syndactyly type I is an autosomal dominant condition with complete or
partial webbing between the third and fourth fingers or the second and
third toes or both. We report here a previously undescribed phenotype
of severe mesoaxial syndactyly and synostosis in patients born to aff
ected parents. The characteristic features of these severe cases are (
1) complete syndactyly and synostosis of the third and fourth fingers;
(2) severe bone reduction in the proximal phalanges of the same finge
rs; (3) hypoplasia of the thumbs and halluces; (4) aplasia/hypoplasia
of the middle phalanges of the second and fifth fingers; and (5) compl
ete or partial soft tissue syndactyly of the toes. We report on three
offspring with this phenotype from two different branches of a syndact
yly type I family, suggesting that they may be homozygous for this con
dition. SSCP and linkage analysis indicated that neither HOXD13 nor ot
her relevant genes in the chromosome 2q31 region was responsible for t
his phenotype.