Mixed vascular naevus syndrome: report of three children with somatic GNA11 mutation and new systemic associations

Mixed vascular naevus (MVN) is characterized by the co-occurrence of telangiectatic capillary malformation and naevus anaemicus, which can appear as a pure cutaneous phenotype or be combined with systemic manifestations such as brain malformations, neurological abnormalities and musculoskeletal disorders. Recently, GNA11 and GNAQ somatic mutations have been reported in some patients with isolated and syndromic MVN. We report three children with MVN syndrome with generalized cutaneous manifestations and a number of systemic associations not reported to date, including ophthalmological anomalies, musculoskeletal abnormalities such as Sprengel deformity and posterior vertebral fusion anomalies, and septal heart defects. We also confirm a somatic mutation of GNA11 in both telangiectatic naevus and naevus anaemicus in two of our patients and discuss a possible common pathogenic mechanism underlying the different manifestations of the syndrome. Currently, there are no guidelines for the evaluation of patients with MVN syndrome, but according to the different known aspects of the disease, a complete clinical examination should be made, and complementary laboratory and imaging tests should be considered.