To describe clinical and neurodevelopmental phenotypes of
Costello syndrome, we performed a retrospective review of the clinical records and findings in 10 children with
Costello syndrome. All patients showed significant postnatal growth retardation and severe feeding difficulties leading to
failure to thrive from early infancy. All required
tube feeding and some needed high-calorie formulas for variable periods. Developmental quotients/IQs in seven children were 50 or less, and three were in the mildly retarded range. Five had
seizures. Remarkable manifestations not previously reported were the characteristic behavior in infancy. Although happy and sociable personality was always emphasized in the genetic literature, all children showed significant irritability, including
hypersensitivity to sound and tactile stimuli, sleep disturbance, and excess shyness with strangers in infancy. Those symptoms usually disappeared around age 2-4 years. Other clinical signs included cardiac abnormalities (8),
musculoskeletal abnormalities (10), ophthalmological manifestations (5), increased urinary vanillymandelic
acid (VMA) and
homovanillic acid (HVA) (3),
rhabdomyosarcoma (1),
laryngomalacia (1), and
cryptorchidism (1). Only three girls had papillomata. Family histories were negative for
Costello syndrome. In conclusion, we confirm the wide spectrum of mental function in patients with
Costello syndrome, which ranges from severe to mild. During infancy
Costello syndrome showed remarkable irritability with severe feeding problems, which attributes significant difficulties to the parents of affected children.