Hypomelanosis of Ito and a ‘mirror image’ whole chromosome duplication resulting in trisomy 14 mosaicism

Abstract

We describe a female infant with multiple congenital anomalies including unusual hyperpigmentation, tetralogy of Fallot, absent corpus callosum and wide prominent nasal bridge. The infant was initially seen for genetic consultation on day one after birth. Chromosome analysis from cultured lymphocytes showed a normal 46,XX karyotype. However, cultured skin fibroblasts showed mosaicism with 46,XX,add(14)(q32).ish psu dic dup(14)(q32p13)(wcp14+)/46,XX complements. A review of the published report with chromosome mosaicism and hypomelanosis of Ito (HMI) is included. We suggest that the trisomy 14 mosaicism seen in fibroblast cultures has importance in the expression of pigmentation dysplasias in this patient. Pigmentary anomaly may be due to loss or gain of specific genes that influence pigmentation located on the long arm of chromosome 14 in this patient.