Total 49 clinical symptoms reported for Phelan-McDermid syndrome  Very Frequent (7)Occasional (24)Frequent (18)

Accelerated skeletal maturation	An abnormally increased rate of skeletal maturation. Accelerated skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body.   Synonyms:Advanced bone age; Early bone maturation	Very frequent
Bruxism	Bruxism is characterized by the grinding of the teeth including the clenching of the jaw and typically occur during sleep.   Synonyms:Teeth grinding	Very frequent
Delayed speech and language development	A degree of language development that is significantly below the norm for a child of a specified age.   Synonyms:Deficiency of speech development; Delayed language development; Delayed speech; Delayed speech acquisition; Delayed speech and language development; Delayed speech development; Impaired speech and language development; Impaired speech development; Language delay; Language delayed; Language development deficit; Late-onset speech development; Poor language development; Speech and language delay; Speech and language difficulties; Speech delay	Very frequent
Hypoplastic toenails	Underdevelopment of the toenail.   Synonyms:Underdeveloped toenails	Very frequent
Impaired pain sensation	Reduced ability to perceive painful stimuli.   Synonyms:Decreased pain sensation; Decreased pinprick sensation; Impaired pain sensation	Very frequent
Macrotia	Median longitudinal ear length greater than two standard deviations above the mean and median ear width greater than two standard deviations above the mean (objective); or, apparent increase in length and width of the pinna (subjective).   Synonyms:Large ears; Large pinnae	Very frequent
Neonatal hypotonia	Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period.   Synonyms:Hypotonia, in neonatal onset; Hypotonia, neonatal; Low muscle tone, in neonatal onset	Very frequent