Costello described the phenotypic features in 1977.


Inheritance: autosomal dominant (Jones), autosomal recessive (Zampino et al)


Growth and development

(1) severe failure to thrive initially with poor weight gain

(2) short stature

(3) disproportionate weight gain with age


Head and neck:

(1) curly hair

(2) coarse facial features

(3) nasal and/or perioral papillomas (absent in infancy, appear during childhood or adolescence)

(4) relative macrocephaly

(5) macroglossia and thickened lips

(6) thick eyebrows

(7) low set ears with posterior angulation and hypertrophied lobes

(8) epicanthal folds

(9) palpebral fissures downslanting

(10) strabismus

(11) nose short and bulbous with depressed nasal bridge

(12) dental abnormalities

(13) short neck

(14) difficulty swallowing


Cognitive and CNS

(1) mental retardation

(2) seizures

(3) cerebral atrophy

(4) sociable personality



(1) skin of hands and feet thick and coarse (hyperkeratotic) and loose

(2) deep palmar and plantar creases

(3) dystrophic nails

(4) malpositioned toes

(5) limited extension of elbows

(6) hyperextensible fingers

(7) tight Achilles tendons



(1) hypertrophic cardiomyopathy

(2) cardiac arrhythmias

(3) pulmonary valve stenosis

(4) atrial and/or ventricular septal defect



(1) anal papilloma

(2) tumors (rhabdomyosarcoma, bladder carcinoma, etc)

(3) hypotonia with poor suck as infant

(4) dark skin

(5) inguinal hernia(s)


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