Symptoms of M2DS include infantile hypotonia and failure to thrive, delayed psychomotor development, impaired speech, abnormal or absent gait, epilepsy, spasticity, gastrointestinal motility problems, recurrent infections, and genitourinary abnormalities. Many of those affected by M2DS also fit diagnostic criteria for autism. M2DS can be associated with syndromic facies, namely an abnormally flat back of the head, underdevelopment of the midface, ear anomalies, deep-set eyes, prominent chin, pointed nose, and a flat nasal bridge.
MECP2 duplication syndrome
Cornelia de Lange syndrome
Ayazi syndrome
8p23.1 duplication syndrome
TORCH syndrome
SYNGAP1-related intellectual disability
22q11.2 duplication syndrome
ATR-16 syndrome