CASE REPORT

The male patient was born to a non-consanguineous Japanese couple. The mother was 28 and the father was 29 years old at the time of his birth. The mother had a healthy boy from a previous pregnancy. A review of the family history was unremarkable. The pregnancy was uneventful, except for the presence of polyhydramnios from 27 weeks of gestation. The patient was born by spontaneous vaginal delivery at 35 weeks' gestation with Apgar scores of 6 at one minute and 8 at five minutes. Birth weight was 3622 g (above the 99th centile), height 46.5 cm (60th centile), and head circumference 37.0 cm (above the 99th centile). He was noted to have hypotonia, macrocephaly, a coarse facial appearance, low set ears with thick lobes, downward slanting palpebral fissures, epicanthic folds, depressed nasal bridge, micrognathia, macroglossia, short neck, redundant skin on the neck, kyphosis, bell shaped thorax, widely spaced nipples, loose skin, deep creases on the palms and soles, hyperpigmentation of the skin, and sparse hair. He had poor feeding and failure to thrive, and his psychomotor development was severely retarded; he smiled at 11 months, gained head control at 2 years 10 months, and crawled at 3 years 8 months. The diagnosis of Costello syndrome was made at 1 year of age based on the history of growth failure, psychomotor …