Bifid cardiac apex in Pallister Killian syndrome: case report

Background: Pallister-Killian syndrome (PKS) is a sporadic, rare chromosomal disorder, caused by tissue-limited mosaicism for an isochromosome 12p (i12p). Prenatal diagnosis of PKS is generally incidental at karyotyping in case of fetal anomaly detection or advanced maternal age. Although clinical presentation of PKS varies, cytogenetic findings are constant, and include a tetrasomy of chromosome 12p diagnosed by chorionic villus sampling, amniocentesis or cordocentesis. We report a case of prenatally diagnosed PKS with unique dysmorphic feature: bifid cardiac apex, a type of morphology that has not been documented ever before in the literature. Case report:. Our patient is the 38-year-old pregnant woman who underwent amniocentesis at 18 weeks and 1 days’ gestation upon of an ultrasonographic imaging of fetal cleft lip and advanced maternal age. Cytogenetic analysis of amniotic fluid detected a male mosaic karyotype with a supernumerary chromosome (SMC) in 18/28 (64%) of fetal amniocytes. To determine the chromosomal origin of SMC, fluorescence in situ hybridization (FISH) was performed on metaphase spread chromosomes and mosaicism of tetrasomy 12p was confirmed: mos 47, XY, +mar[18]/46, XY[10].ish i(12p)(8M16/SP6++, CEP12+, VIJyRM2196-). Ultrasound examination showed a male fetus with abnormal facial profile, an echogenic focus in the left ventricle of the heart and shortened fetal long bones. After receiving a genetic counseling for established diagnosis of PKS, the woman requested a termination of pregnancy due to medical reasons. A postmortem inspection and autopsy of the fetus revealed a complex heart anomaly that includes bifid cardiac apex and ventricular septal defect. Conclusion: This report expands the clinical manifestations of PKS with a unique feature of bifid cardiac apex, and highlights the targeted diagnosis of Pallister-Killian syndrome in a second and third trimester of pregnancy if specific ultrasound markers are present.