Pallister–Killian syndrome is a dis

Pallister–Killian syndrome is a disorder associated with global developmental delay, multiple congenital anomalies, and mosaicism for isochromosome 12p. Our five patients exhibited typical phenotypes of PKS, including classic dysmorphic features, global developmental delay, receptive or conductive hearing impairment, strabismus, and gastroesophageal reflux disease ([GERD] Table ​Table2;2; Wilkens et al., 2012). In our series, no patients manifested CDH since the latter associates with complications leading to fetal demise, or it could be diagnosed prenatally and subsequent a termination of pregnancy (Blyth et al., 2015). One patient demonstrated cardiac anomalies which are frequently observed in PKS patients. Epilepsy in PKS usually occurs in the first 4 years of life (Blyth et al., 2015; Wilkens et al., 2012). We observed epilepsy in three of five patients starting between 4 and 7 years; the other two patients are young (3 years and 4 and half years) and therefore a long‐term follow‐up will be needed in order to completely rule out the possibility of manifesting epilepsy. One patient showed optic nerve hypoplasia which has rarely been reported in PKS (Blyth et al., 2015).