Danarti R, Happle R, König A
Department of Dermatology, Philipp University, Marburg, Germany.
Dermatology. 2001;203(3):208-11. doi: 10.1159/000051750.
Cutis marmorata telangiectatica congenita (CMTC) is a rare congenital vascular anomaly that virtually always occurs sporadically and in a patchy, quadrant, unilateral or otherwise segmental manifestation. This would suggest mosaicism of a postzygotic mutation. Some authors, however, described CMTC occurring in several members of a family. This paradox may be explained by the concept of paradominant inheritance. Heterozygous individuals carrying a 'paradominant' mutation are, as a rule, phenotypically normal. The mutation can therefore be transmitted unperceived through many generations. The trait only becomes manifest when a postzygotic mutation occurring during early embryogenesis gives rise to loss of heterozygosity and forms a mosaic population of cells being either homozygous or hemizygous for the mutation. This concept may explain the occasional familial occurrence of CMTC.
先天性大理石样皮肤毛细血管扩张症（CMTC）是一种罕见的先天性血管异常，几乎总是散发性出现，表现为斑片状、象限性、单侧性或以其他方式呈节段性。这提示可能存在合子后突变的嵌合体现象。然而，一些作者描述了CMTC在一个家族的多个成员中出现。这种矛盾现象可以用显性遗传的概念来解释。携带“显性”突变的杂合个体通常表型正常。因此，该突变可以在多代中未被察觉地传递。只有当早期胚胎发育过程中发生的合子后突变导致杂合性丧失，并形成对该突变呈纯合或半合状态的细胞嵌合体群体时，该性状才会显现出来。这一概念可以解释CMTC偶尔出现的家族性发病情况。
