3MC Syndrome [3 genes]

3MC syndrome (an acronym that stands for Malpuech, Michels, Mingarelli, and Carnevale) is a group of autosomal recessive syndromes previously considered separate entities and currently recognized as part of a common clinical spectrum. It is characterized by facial dysmorphism, cleft lip and/or palate, craniosynostosis, learning disabilities, radioulnar synostosis, and genital and vesicorenal anomalies. Among the least common features described are anterior chamber defects, cardiac abnormalities, caudal appendage, umbilical hernia/omphalocele, and diastasis recti.

• <1/1,000,000 individuals (ORPHA:293843)

Analysis using an NGS panel allows accurately confirming diagnosis, which is particularly relevant given the high degree of phenotypic overlap with other dysmorphic syndromes, which complicates diagnosis by clinical criteria only. The use of a panel provides an efficient and cost-effective approach that allows guiding clinical management in a more specific manner, anticipating malformations or complications that are characteristic of this disorder. Accurate molecular identification enables genetic counseling, assessment of risk of recurrence, and reproductive decision-making in affected families.

This panel is indicated in the presence of a compatible phenotype, i.e. patients with typical facial dysmorphism (such as hypertelorism, blepharophimosis, ptosis, arched eyebrows, cleft lip/palate) and/or genitourinary or renal malformations, radioulnar synostosis, or craniosynostosis, especially when the phenotype overlaps with other syndromes and clinical diagnosis is inconclusive.