Postaxial polydactyly is characterised by fifth digit duplications in hands and/or feet. Two phenotypic varieties have been described. In type A, the extra digit is well formed and articulates with the fifth or an extra metacarpal. A rudimentary extra fifth digit characterises type B. Mutations in the GLI3 gene are associated with postaxial polydactyly in some families and a second locus has been identified on chromosome 13 but the majority of cases remain unexplained. We report here a third locus for postaxial polydactyly on chromosome 19p13.1-13.2 in a large Chinese kindred with a combination of type A and B. Two-point linkage analysis showed the highest LOD score (Zmax=5.85 at χ=0 cM) at marker D19S221. Recombination events with markers D19S1165 and D19S929 define the critical region for this postaxial polydactyly locus to a region of 4.3 cM on the genetic map.

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doi.org/10.1038/sj.ejhg.5200790, hdl.handle.net/1765/107302
European Journal of Human Genetics

Zhao, H. (Hongshan), Tian, Y., Breedveld, G., Huang, S., Zou, Y., Chai, J.Y.J. (Jue Y. Jinghua), Li, H. (Hui), Li, M. (Mingyue), Oostra, B., Lo, W.& Heutink, P. (2002). Postaxial polydactyly type A/B (PAP-A/B) is linked to chromosome 19p13.1-13.2 in a chinese kindred. European Journal of Human Genetics, 10(3), 162–166.https://doi.org/10.1038/sj.ejhg.5200790