Capillary malformation-arteriovenous malformation syndrome. A multicenter study.

Introduction Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is a rare syndrome that associates characteristic skin lesions with fast-flow vascular malformations (FFVM) in one-third of patients. Few case series have been described, and none in Spain. Methods We conducted an observational study of patients with CM-AVM syndrome diagnosed in 15 Spanish hospitals over 3 years. The main clinical, radiological, genetic findings and associated diseases were analyzed. Results Sixty-four patients have been collected. In 26.5% of the cases, the diagnosis was incidental. In 75% of patients, one macule significantly larger was identified, which we have called herald patch. FFVMs have been detected in 34% of the patients, distributed in 30% on the skin, in 7.8% on the brain, and in 1.5% at the spinal level. 65% had a positive family history. 42 out of 57 patients tested (73%) were positive for the RASA1 mutations, and all 4 patients tested for EPHB4 mutations were positive. No tumor lesions were detected in the series, except for 5 infantile hemangiomas. Conclusions The data that we have obtained regarding clinical lesions, associated FFVM, family history, and genetics are similar to those previously published in the literature. An extensive data analysis failed to demonstrate any statistically significant association between the presence of a FFVM and any clinical, familiar, or genetic parameter that could predict its onset, although a link between the presence of a herald patch on the midline face and a brain FFVM could be observed. No correlation between genotype and phenotype could be detected neither.