Andreano G, Dobosz M, Boschi I, Ruscitti L E, Liberti A, Casa D
Servizio di Genetica Medica, Università degli Studi La Sapienza di Roma.
Acta Genet Med Gemellol (Roma). 1998;47(1):43-9.
It is generally held that there are genetic factors for dizygotic (DZ) twinning, but the pattern of inheritance is far from clear. We report on a rare pedigree with three sets of spontaneous DZ female twin births in three successive generations. To our knowledge no similar pedigrees have been reported in literature. Zygosity determination in three pairs of twins was performed with ABO, MN and Rh blood groups from erythrocytes and with STR analysis from samples of saliva. In our pedigree, the direct transmission of the DZ twinning through the maternal line seems show an autosomal dominant pattern of inheritance. We believe that the inheritance of DZ twinning appears to be recessive in most case and autosomal dominant only in rare instances. It is plausible with the hypothesis that the expression of the dizygotic twinning trait in a mother shows a genetic heterogeneity.
一般认为，双卵双胞胎（DZ）存在遗传因素，但遗传模式远未明确。我们报告了一个罕见的家系，连续三代出现了三组自发的女性双卵双胞胎。据我们所知，文献中尚未报道过类似的家系。通过红细胞的ABO、MN和Rh血型以及唾液样本的STR分析对三对双胞胎进行了合子性测定。在我们的家系中，双卵双胞胎通过母系的直接传递似乎显示出常染色体显性遗传模式。我们认为，双卵双胞胎的遗传在大多数情况下似乎是隐性的，仅在罕见情况下是常染色体显性的。有一种假设认为，母亲体内双卵双胞胎性状的表达表现出遗传异质性，这是有道理的。
