Cutis marmorata telangiectatica congenita being caused by postzygotic GNA11 mutations.

Cutis marmorata telangiectatica congenita (CMTC) is characterized by coarse-meshed capillary malformations arranged in asymmetrically distributed patches. The disorder may be associated with hyper- or hypoplastic limbs, syndactyly, cleft palate, and glaucoma. Because the disease usually occurs sporadically, the concept of a lethal mutation surviving by mosaicism was proposed about 30 years ago. Here we describe three children with CMTC due to a postzygotic GNA11 mutation c547C > T (p.Arg183Cys), documented in saliva (patient 1) or lesional cutaneous tissue (patients 2 and 3). All three individuals had widespread and asymmetric CMTC which was present from birth and became fainter during the first years of life. Variably associated anomalies included glaucoma, choroidal capillary malformation, and body asymmetry. In previous case reports, postzygotic GNA11 mutations were documented in two cases of phacomatosis cesiomarmorata, being characterized by CMTC coexisting with segmental dermal melanocytosis. Moreover, postzygotic GNA11 mutations were noted in two CMTC patients described under the incorrect diagnosis of "nevus vascularis mixtus". Hence, the present cases convincingly support the concept that CMTC can be caused by mosaic GNA11 mutations and thus belongs to the GNA11-Related Capillary Nevus (GNARCAN) spectrum. In two other bona fide cases of CMTC, however, we were unable to find a mutation in GNA11, which may be explained either by our inability to detect a very low percentage of mutant cells or by genetic heterogeneity of the phenotype.