Definition:

3MC syndrome is an autosomal recessive heterogeneous disorder with features linked to developmental abnormalities. Patients with 3MC syndrome may exhibit a spectrum of developmental features, including developmental delay, growth and mental retardation, and characteristic facial dysmorphism, such as hypertelorism, telecanthus, blepharophimosis, blepharoptosis, and epicanthus inversus. 3MC syndrome was originally described as four separate disorders: Malpuech syndrome, Carnevale syndrome, Michels syndrome, and Mingarelli syndrome. There is considerable overlap between them, which have similarities in facial appearance, leading to the suggestion that they should all be considered part of the same phenotypic spectrum known as 3MC syndrome. Mutations in lectin complement pathway genes have been reported to cause 3MC syndrome.