title: Identification of a region of homozygous deletion on 8p22-23.1 in medulloblastoma.
abstract: To identify critical tumor suppressor loci that are associated with the development of medulloblastoma, we performed a comprehensive genome-wide allelotype analysis in a series of 12 medulloblastomas. Non-random allelic imbalances were identified on chromosomes 7q (58.3%), 8p (66.7%), 16q (58.3%), 17p (58.3%) and 17q (66.7%). Comparative genomic hybridization analysis confirmed that allelic imbalances on 8p, 16q and 17p were due to loss of genetic materials. Finer deletion mapping in an expanded series of 23 medulloblastomas localized the common deletion region on 8p to an interval of 18.14 cM on 8p22-23.2. We then searched within the region of loss on 8p for loci that might contain homozygous deletion using comparative duplex PCR. An overlapping homozygous deletion region was identified in a 1.8 cM interval on 8p22-23.1, between markers D8S520 and D8S1130, in two medulloblastomas. This region of homozygous deletion also encompasses the 1.4 cM minimal deletion region detected on 8p in ductal carcinoma in situ of breast. In conclusion, we reported for the first time a detailed deletion mapping on 8p in medulloblastoma and have identified a region of homozygous deletion on 8p22-23.1 that is likely to contain a critical tumor suppressor gene involved in the development of medulloblastoma.
authors.affiliation: Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Xiao-lu
authors.initials: XL
authors.lastname: Yin
authors.forename: Jesse Chung-sean
authors.initials: JC
authors.lastname: Pang
authors.forename: Ho-keung
authors.initials: HK
authors.lastname: Ng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D022981:Allelic Imbalance / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons / Q000235:genetics; D005260:Female; D020690:GTPase-Activating Proteins; D017353:Gene Deletion; D006720:Homozygote; D006801:Humans; D008297:Male; D008527:Medulloblastoma / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D009690:Nucleic Acid Conformation; D020161:Physical Chromosome Mapping; D016133:Polymerase Chain Reaction; D025521:Tumor Suppressor Proteins / Q000235:genetics
chemical_list: C112352:DLC1 protein, human; D020690:GTPase-Activating Proteins; D025521:Tumor Suppressor Proteins