Chromosome locus: 16p11.2
Gene: SRCAP (SNF2-related CBP activator protein)
Protein: helicase SRCAP
Inheritance: autosomal dominant or de novo
Clinical features:
(1) low birth weight
(2) short stature as child and adult with stocky habitus
(3) bone delay during early childhood that normalizes by 12 years of age
(4) craniofacial features (see below)
(5) skeletal anomalies (see below)
(6) severe impairment of expressive and receptive language
(7) high-pitched and hypernasal voice
(8) dysarthria and verbal dyspraxia
(9) intellectual disability
(10) difficulties in behavior and temperament
(11) seizures
(12) gastroesophageal reflux
(13) renal anomalies (renal agenesis, cysts, hydronephrosis)
(14) genital anomalies (undescended testes in male, hypospadias in male)
Craniofacial features:
(1) normal head circumference
(2) triangular face
(3) deep-set eyes
(4) long nose with narrow bridge, broad base, full tip
(5) wide mouth with thin vermilion border of the upper lip
(6) short philtrum
(7) hyperopia and/or strabismus
(8) low-set ears
(9) conductive hearing loss
(10) dental abnormalities
Skeletal anomalies:
(1) brachydactyly
(2) clubbing
(3) clinodactyly
(4) short thumbs
(5) prominent joints
(6) clavicular abnormalities
