Zhao Hongshan, Tian Yong, Breedveld Guido, Huang Shangzhi, Zou Ying, Y Jue, Chai Jinghua, Li Hui, Li Mingyue, Oostra Ben A, Lo Wilson H Y, Heutink Peter
Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, WHO Collaboration Center of Community Control for Inherited Diseases, Beijing, People's Republic of China.
Eur J Hum Genet. 2002 Mar;10(3):162-6. doi: 10.1038/sj.ejhg.5200790.
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 (Z(max) = 5.85 at theta; = 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.
轴后多指畸形的特征是手和/或脚出现第五指重复。已描述了两种表型变体。在A型中，额外的手指发育良好，并与第五掌骨或额外的掌骨相连。B型的特征是有一个发育不全的额外第五指。在一些家族中，GLI3基因突变与轴后多指畸形有关，并且已在13号染色体上确定了第二个基因座，但大多数病例仍无法解释。我们在此报告一个大型中国家系中位于19号染色体p13.1 - 13.2区域的轴后多指畸形的第三个基因座，该家系同时存在A型和B型。两点连锁分析显示，在标记D19S221处获得最高LOD值（θ = 0 cM时，Z(max) = 5.85）。与标记D19S1165和D19S929的重组事件将该轴后多指畸形基因座的关键区域定位到遗传图谱上4.3 cM的区域。
