Clinical features associated with MASP1-related 3MC syndrome include:
• Craniofacial features: hypertelorism, ptosis, blepharophimosis, downslanting palpebral fissures, high-arched eyebrows, cleft lip and/or palate, broad nasal bridge.
• Musculoskeletal anomalies: caudal appendage, radioulnar synostosis, clinodactyly, craniosynostosis.
• Growth-related findings: postnatal short stature.
• Hearing loss, typically sensorineural.
• Genitourinary anomalies: including hypospadias and cryptorchidism.
• Abdominal wall defects: such as omphalocele or umbilical hernia.
• Cardiac defects and anterior chamber eye anomalies may also be present.
• Neurodevelopmental involvement ranges from normal cognition to mild intellectual disability.
The phenotypic spectrum is broad, and not all individuals with pathogenic MASP1 variants present with all features.
MASP1