title: New diagnostic method for Pallister-Killian syndrome: detection of i(12p) in interphase nuclei of buccal mucosa by fluorescence in situ hybridization.
abstract: Detection of the supernumerary isochromosome 12p [i(12p)] was performed on buccal smear preparations from 2 patients with Pallister-Killian syndrome, 21 (patient 1) and 15 months (patient 2) old, by interphase fluorescence in situ hybridization (FISH) using a chromosome 12-specific alpha satellite probe. Isochromosome 12p-positive cells were identified by observing 3 signals over the nucleus, while diploid cells had 2 signals. The proportion of i(12p)-positive cells thus identified was high in the epithelial cells of buccal mucosa at 68 and 53% from patients 1 and 2, respectively. Further, the frequencies of i(12p)-positive cells were also studied in PHA-stimulated peripheral lymphocytes, cultured skin fibroblasts (both patients), and directly harvested T and B-cells (patient 1). Of these tissues, buccal mucosa showed the highest proportion of i(12p)-positive cells. These findings indicate that epithelial cells of buccal mucosa are likely to retain i(12p)-positive cells. Detection of i(12p) using direct buccal smear preparations by interphase FISH is a rapid, effective and non-invasive method for confirming the diagnosis of the Pallister-Killian syndrome.
authors.affiliation: Division of Medical Genetics, Saitama Children's Medical Center, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ohashi
authors.forename: S
authors.initials: S
authors.lastname: Ishikiriyama
authors.forename: Y
authors.initials: Y
authors.lastname: Fukushima
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics / Q000473:pathology*; D002467:Cell Nucleus / Q000473:pathology; D002881:Chromosomes, Human, Pair 12; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics / Q000473:pathology*; D007399:Interphase / Q000235:genetics; D008297:Male; D009061:Mouth Mucosa / Q000473:pathology / Q000648:ultrastructure; D013577:Syndrome