Supernumerary Ring Chromosome: An Etiology for Pallister-Killian Syndrome?

• Published in: Fetal diagnosis and therapy Vol. 34; no. 3; pp. 172 - 175
• Main Authors: Lloveras, E., Canellas, A., Cirigliano, V., Català, V., Cerdan, C., Plaja, A.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland Karger 01.10.2013; S. Karger AG
• Subjects: Adult; Biological and medical sciences; Chromosome Disorders - genetics; Chromosomes, Human, Pair 12 - genetics; Comparative Genomic Hybridization; Female; Gynecology. Andrology. Obstetrics; Humans; Isochromosomes; Karyotype; Medical sciences; Mosaicism; Novel Insights from Clinical Practice; Pregnancy; Pregnancy. Fetus. Placenta; Prenatal Diagnosis; Tissue-limited mosaicism; Prenatal diagnosis; Ring chromosome; Pallister-Killian syndrome; Array CGH; Chromosomal aberration; Aneuploidy; Pallister syndrome; Genetic disease; Tissue; Malformation; Etiology; Supernumerary chromosome; Ulnar mammary syndrome; Abnormal chromosome; Mosaicism; Limit; Complex syndrome
• ISSN: 1015-3837; 1421-9964
• DOI: 10.1159/000347049

Characterization of marker chromosomes before the introduction of array CGH (aCGH) assays was only based on their banding patterns (G, C, and NOR staining) and fluorescent in situ hybridization techniques. The use of aCGH greatly improves the identification of marker chromosomes in some cases. We describe an atypical case of Pallister-Killian syndrome (PKS) detected at prenatal diagnosis with a very unusual cytogenetic presentation: a supernumerary ring chromosome including two copies of 12p. A similar anomaly described in a postnatal patient suggests ring chromosome as a possible cause of PKS. Extra ring chromosomes might be a more common etiology for PKS than previously thought, given the difficulty in their characterization before the advent of aCGH.