Association of arrhythmia and sudden death in macrocephaly-cutis marmorata telangiectatica congenita syndrome.

Macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC) constitutes a distinct entity characterized by prenatal overgrowth, macrosomia, hemihypertrophy, macrocephaly, nonobstructive hydrocephaly, frontal bossing, hypotonia, developmental delay, generalized or facial capillary malformation with upper philtral nevus flammeus and cutis marmorata, joint hypermobility, loose skin, toe syndactyly, and postaxial polydactyly. All but one of the cases reported previously had benign clinical courses without showing an increased risk of early infant death. We describe three additional cases with poor clinical outcomes including severe postnatal growth failure, intractable cardiac arrhythmia in two cases, and sudden infant death in two cases. Arrhythmia has not been described previously as one of the symptoms of M-CMCT. Patients with M-CMTC associated with severe postnatal growth failure and arrhythmia may constitute a distinct clinical subtype of M-CMTC with an increased risk of life-threatening episodes or sudden death. Recognizing this clinical subtype of M-CMTC is important to prevent these serious potential complications.