Boklage C E
Acta Genet Med Gemellol (Roma). 1981;30(3):167-87. doi: 10.1017/s0001566000007649.
In 773 three-generation families of twins, individual probability of nonrighthandedness (NRH) depends significantly on the handedness of that individual's parents. The parents of twins are much more often NRH than are their nontwinbearing siblings. The twins and their siblings apparently inherit the excess liability for NRH shown by their parents. Monozygotic (MZ) pairs are significantly about twice as often concordant (casewise) for handedness as dizygotic (DZ) pairs. Overall, the best-fitting mode of transmission is autosomal, NRH dominant to RH with penetrance of about 50% in the heterozygote, or multifactorial, with heritability of 60-70%. Under the major-gene approach, heterogeneity seems likely, with about one-third of the families showing no NRH outside of the twin sibships. MZ/DZ concordance ratio is about four in those families, suggestive of recessive inheritance. A 1.16-fold excess of NRH in twins compared to their siblings, and a 1.8-fold excess in the second-born members of same-sex discordant paris, leaves open the possibility that a minor portion of NRH in twins may be secondary to transient hypoxia and/or acidosis.
在773个三代双胞胎家庭中，个体非右利手（NRH）的概率显著取决于其父母的利手情况。双胞胎的父母比其未生育双胞胎的兄弟姐妹更常表现为非右利手。双胞胎及其兄弟姐妹显然继承了父母所表现出的非右利手的额外易感性。同卵双胞胎（MZ）在利手方面的一致性（逐例）明显是异卵双胞胎（DZ）的两倍左右。总体而言，最符合的遗传模式是常染色体遗传，非右利手对右利手呈显性，杂合子的外显率约为50%，或者是多基因遗传，遗传度为60 - 70%。在主基因方法下，似乎存在异质性，约三分之一的家庭在双胞胎同胞关系之外未出现非右利手情况。在这些家庭中，同卵/异卵一致性比率约为4，提示隐性遗传。与他们的兄弟姐妹相比，双胞胎中非右利手的比例高出1.16倍，在同性不一致双胞胎对中，第二个出生的成员中非右利手的比例高出1.8倍，这使得双胞胎中非右利手的一小部分可能继发于短暂性缺氧和/或酸中毒成为一种可能性。
