A Case of Pallister–Killian Syndrome in a Newborn

Background: Pallister-Killian syndrome (PKS) is a rare disorder caused by tissue-limited mosaicism tetrasomy of chromosome 12p. Affected newborns show a typical dysmorphic pattern: macrosomia, coarse facies, hypertelorism, small nose with long philtrum, V-shaped upper lip, low set ears, frontotemporal alopecia, and patchy pigmentary skin and hair anomalies. Seizures and developmental delay, cardiac defects, diaphragmatic hernia, and renal/anal malformations may be associated. Case: Here, we report the case of a newborn with multiple congenital malformations, later diagnosed with PKS. Conclusions: Phenotypic and cytogenetic variability of PKS, together with the lack of correlation between tetrasomic cells' proportion and disease severity, may be challenging for diagnosis. Therefore, a detailed physical examination is mandatory for early clinical suspicion and to guide further investigations. The usefulness of array-CGH performed on peripheral blood should also be emphasized as a sensitive diagnostic tool.