title: Epilepsy and neurological findings in 11 individuals with 1p36 deletion syndrome.
abstract: The 1p36 deletion syndrome is a newly delineated multiple congenital anomalies/mental retardation syndrome characterized by mental retardation, growth delay, epilepsy, congenital heart defects, characteristic facial appearance, and precocious puberty. We analyzed 11 patients by fluorescence in situ hybridization (FISH) using commercially available bacterial artificial chromosome and P1-derived artificial chromosome genomic clones to define the chromosomal deletion responsible for the 1p36 deletion syndrome. Cytogenetic investigation revealed two cases with a terminal deletion of 1p36. Nine patients had an apparently normal karyotype with standard G-bands by trypsin using Giemsa (GTG), but FISH screening with the highly polymorphic genetic marker D1Z2, which is mapped to 1p36.3 and contains an unusual reiterated 40-bp variable number tandem repeat, revealed a submicroscopic deletion. All patients had severe to profound mental retardation. Based on the University of California Santa Cruz Genome Browser, we constructed a deletion map and analyzed the relationship between neurological findings and chromosomal deletions for the 11 cases. Six cases had intractable epilepsy and three had no seizures. The common deletion interval was about 1 million base pairs (Mbp) located between RP11-82D16 and RP4-785P20 (Rho guanine exchange factor (GEF) 16). The severity of clinical symptoms correlates with the size of the deletion. This is demonstrated by the 3 patients with at least 8Mbp deletions that display profound mental retardation and congenital heart defects. Although haploinsufficiency of the potassium channel beta-subunit (KCNAB2) is thought to be responsible for intractable seizures in the 1p36 deletion syndrome, this was not the case for 3 of the 11 patients in this study. Further investigation of the 1p36 region is necessary to allow identification of genes responsible for the 1p36 deletion syndrome.
authors: Division of Medical Genetics, Clinical Research Institute, Kanagawa Children's Medical Center, Yokohama, Kanagawa 232-8555, Japan. kkuros@bekkoame.ne.jp
authors: Kenji
authors: K
authors: Kurosawa
authors: Hiroshi
authors: H
authors: Kawame
authors: Nobuhiko
authors: N
authors: Okamoto
authors: Yukikatsu
authors: Y
authors: Ochiai
authors: Akira
authors: A
authors: Akatsuka
authors: Masahisa
authors: M
authors: Kobayashi
authors: Masayuki
authors: M
authors: Shimohira
authors: Seiji
authors: S
authors: Mizuno
authors: Kazuko
authors: K
authors: Wada
authors: Yoshimitsu
authors: Y
authors: Fukushima
authors: Hisashi
authors: H
authors: Kawawaki
authors: Toshiyuki
authors: T
authors: Yamamoto
authors: Mitsuo
authors: M
authors: Masuno
authors: Kiyoshi
authors: K
authors: Imaizumi
authors: Yoshikazu
authors: Y
authors: Kuroki
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics* / Q000503:physiopathology*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D025063:Chromosome Disorders / Q000235:genetics* / Q000503:physiopathology*; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics / Q000503:physiopathology; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics / Q000503:physiopathology; D008297:Male