Prenatally identified Pallister–Killian syndrome: Ultrasound pattern and diagnostic considerations

Introduction Pallister – Killian syndrome (PKS; OMIM #601803) is a sporadic rare chromosomal disorder (1: 25,000) (Pallister et al. 1977; Srinivasan and Wright 2014). Th is syndrome may comprise webbed neck, low-set ears, lower jaw tooth bud, left simian crease, shield chest, streaks of hypo (hyper)pigmentation or focal aplasia cutis, diaphragmatic hernia, hypoplastic lungs, agenesis of pericardium, Meckel ’ s diverticulum, severe mental retardation, hypotonia, seizures, heart defects and other systemic abnormalities (Mourali et al. 2010). Th e facial dysmorphism is characterised by coarse and fl at facies, macroglossia, prognathia and everted lower lip, which is a pattern similar to that observed in Fryns syndrome (Rodr í guez et al. 1994). PKS is caused by mosaicism for isochromosome 12p. Th is mosaicism is usually limited to skin fi broblasts, which have 47 chromosomes with an extra small metacentric chromosome, while lymphocytes display a normal karyotype (Ozl ü et al. 2014). Here we report a case of prenatally diagnosed PKS. Th is case report is in accordance with the Helsinki Declaration, COPE guidelines (http://publicationethics.org/), Uniform Requirements for Manuscripts Submitted to Biomedical Journals, the CARE guideline available through the EQUATOR network (http:// www.equator-network.org/), and approved by an independent Institutional Review Board or IRB.