A premature infant with Costello syndrome due to a rare G13C HRAS mutation

Costello syndrome is caused by mutations in the HRAS proto‐oncogene whose clinical features in the first year of life include fetal and neonatal macrosomia with subsequent growth impairment due to severe feeding difficulties. We report on a premature male with Costello syndrome due to a rare G13C HRAS mutation and describe his clinical features and evolution during the first year of life. The diagnosis of Costello syndrome may be difficult at birth, especially in very preterm infants in whom feeding difficulties, reduced subcutaneous adipose tissue and failure to thrive are also part of their typical presentation. © 2009 Wiley‐Liss, Inc.