Trisomy 14 mosaicism in a 5-year-old boy.

We report on a 5-year-old boy with failure to thrive, mental retardation, a broad nose, hypertelorism, slight antimongoloid slant palpebral fissures, mild ptosis, microphthalmia, short and wide neck, apparently acyanotic tetralogy of Fallot, dislocation of the left hip, generalized linear and patchy hyperpigmentation, micropenis, and undescended testes. He had mosaicism of 46,XY/47,XY, + 14 in a ratio of 3:1. Comparisons are made with the other reports of trisomy 14 mosaicism and relationship to incontinentia pigmenti.