title: Functional classification and mutation analysis of a synpolydactyly kindred.
abstract: The aim of the present study was to analyze a congenital syndactyly/polydactyly kindred and propose a new functional classification method of clinical significance. The modes of inheritance and mutational mechanisms were also determined using genetic analyses. Hand and foot anatomy and functions were measured using photographic images, X-ray imaging and grip ability tests. Genetic analysis comprised the genotyping of polymorphic microsatellite markers at known polydactyly-associated loci and the sequencing of the candidate gene. A functional classification system was devised to divide the clinical features into three types, which included mild, moderate or severe deformity. The family was concluded to have syndactyly type II with autosomal dominant inheritance. The microsatellites, D2S2310 and D2S2314, at the 2q31-32 chromosome, which have previously been associated with synpolydactyly type I, were found to be associated with the disorder in the current family. A 27-bp insertion mutation was identified in the affected individuals in theHOXD13gene at this locus. The insertion added a further nine alanine residues to the polyalanine stretch within the encoded protein. In conclusion, the functional classification method described in the present study may be used to guide surgical approaches to treatment. A family was identified in whom expansion of the polyalanine tract in theHOXD13gene causes autosomal dominant hereditary synpolydactyly.
authors.affiliation: Department of Plastic Surgery, Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Jianda
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Plastic Surgery, Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Plastic Surgery, Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Ke
authors.initials: K
authors.lastname: Cao
authors.affiliation: Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, Hunan 410078, P.R. China.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, Hunan 410078, P.R. China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Plastic Surgery, Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Hu
authors.affiliation: Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, Hunan 410078, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Ni
authors.affiliation: Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, Hunan 410078, P.R. China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
keywords: HOXD13 gene; functional classification; linkage; polydactyly; syndactyly