Feitosa M F, Castilla E E, da Graça Dutra M, Krieger H
Departamento de Genética, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
Am J Med Genet. 1998 Dec 28;80(5):466-72. doi: 10.1002/(sici)1096-8628(19981228)80:5<466::aid-ajmg6>3.0.co;2-d.
Data on polydactyly were obtained from two large samples: the Latin American Collaborative Study of Congenital Malformations (ECLAMC), and from a migrant Northeastern Brazilian population of rural origin (Hospedaria). ECLAMC is a case-control clinical epidemiological program comprising 10,035 individuals distributed among 2,030 segregating nuclear families. Hospedaria data consisted of 6,586 examined individuals belonging to 1,040 nuclear families. Using complex segregation analysis methodology we found no evidence of two loci (a major gene and a modifier locus) acting on postaxial polydactyly in the present study. Very high heritability values (in a classical multifactorial model) of postaxial polydactyly were detected, for several sets of analyses in ECLAMC and in Hospedaria. For the whole ECLAMC sample there is a peculiar suggestion of a major recessive gene effect responsible for the trait; however, no comparison with a model involving transmission probabilities (tau) was possible in this highly heterogeneous sample. If the whole ECLAMC sample is divided in subsamples, according to Black admixture proportions, the same multifactorial picture emerges. Two different inheritance patterns were verified for hand (HP) and foot (FP) postaxial polydactyly: For HP there is evidence of a non-Mendelian transmission mechanism, while for FP the parental/sib transmission appears to be due only to multifactorial causes.
拉丁美洲先天性畸形协作研究（ECLAMC）以及巴西东北部农村出身的移民群体（Hospedaria）。ECLAMC是一项病例对照临床流行病学项目，包含10,035名个体，分布在2,030个分离的核心家庭中。Hospedaria的数据包括属于1,040个核心家庭的6,586名受检个体。在本研究中，使用复杂分离分析方法，我们未发现两个基因座（一个主基因和一个修饰基因座）对轴后多指畸形起作用的证据。在ECLAMC和Hospedaria中进行的几组分析均检测到轴后多指畸形具有非常高的遗传度值（在经典多因素模型中）。对于整个ECLAMC样本，有一种特殊的迹象表明存在一个主要的隐性基因效应导致该性状；然而，在这个高度异质的样本中，无法与涉及传递概率（tau）的模型进行比较。如果根据黑人混血比例将整个ECLAMC样本分成子样本，会出现相同的多因素情况。手部（HP）和足部（FP）轴后多指畸形验证了两种不同的遗传模式：对于HP，有证据表明存在非孟德尔遗传传递机制，而对于FP，亲代/同胞传递似乎仅由多因素原因导致。
