Pallister-Killian syndrome: report of one case.

Pallister-Killian Syndrome (PKS) is a rare sporadic congenital anomaly disorder, characterized by multiple congenital anomalies, especially craniofacial dysmorphism. It is also associated with mental retardation, seizure, skin pigmentation, and visceral malformations such as congenital diaphragmatic hernia, congenital heart defect, anorectal anomalies, and genital malformation. This syndrome usually presents with tissue-limited mosaicism of supernumerary 12p isochromosome i (12p). Moreover, diagnosis of Pallister-Killian Syndrome (PKS) is difficult because the ratio of abnormal to normal karyotyping is much lower in peripheral lymphocytes than in skin fibroblasts. We report the first case in Taiwan, who has tetrasomy 12p mosaic in peripheral lymphocytes.