3MC Syndrome, is a rare multiple anomaly disorder characterised by hypertelorism, craniosynostosis, blepharophimosis, ptosis, cleft lip/palate, genitourinary tract anomalies, umbilical defect and caudal appendage. Mild intellectual disability and hearing loss and anterior segment dysgenesis may also be present.
3MC syndrome is the overarching name given to a group of four disorders which were originally delineated clinically as separate but overlapping entities subsequently identified to have the same genetic basis. The abbreviation 3MC therefore encompasses Mingarelli, Malpuech, Michels and Carnevale syndromes. Pathogenic variants in COLEC11, COLLEC10 and MASP1 genes may all be found in individuals with 3MC syndrome. Abnormal expression of these genes leads to impairment in the lectin complementary pathway. This pathway affects neuronal migration in many tissues, particularly in the craniofacial structures.