title: Chromosome-12 mapping of late-onset Alzheimer disease among Caribbean Hispanics.
abstract: Linkage to chromosome 12p for familial Alzheimer disease (AD) has been inconsistent. Using 35 markers near the centromere of chromosome 12, we investigated 79 Caribbean Hispanic families with AD. Two-point linkage analysis using affected sib pairs yielded LOD scores of 3.15 at D12S1623 and 1.43 at D12S1042. The LOD score at D12S1623 decreased to 1.62 in families with late-onset (age >65 years) AD (LOAD), but the LOD score at D12S1042 was unchanged. Among families negative for the apolipoprotein E (APOE-epsilon 4) allele, the LOD score for D12S1623 was lower (1.01), whereas that for D12S1042 increased to 1.73. Among families positive for the APOE-epsilon 4 allele, none of the LOD scores reached 1. Multipoint affected-relative-pair analysis showed peaks at D12S1623 (nonparametric linkage [NPL] score 1.52; P=.028) and near D12S1042, at D12S1057 (NPL score 1.57; P=.027). NPL scores for both D12S1623 and D12S1057 increased in families affected with LOAD, but, in APOE-epsilon 4-negative families, only scores for the region flanking D12S1623 remained elevated (NPL score 1.74; P=.013). This study of Caribbean Hispanics with familial AD extends and provides modest evidence of linkage to loci on chromosome 12p. Linkage varied by age at onset of AD and by the presence or absence of the APOE-epsilon 4 allele.
authors.affiliation: The Taub Institute on Alzheimer's Disease and the Aging Brain, The Gertrude H. Sergievsky Center and Department of Neurology, School of Public Health, Columbia University, New York, NY 10032, USA. rpm2@columbia.edu
authors.forename: R
authors.initials: R
authors.lastname: Mayeux
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: S N
authors.initials: SN
authors.lastname: Romas
authors.forename: D
authors.initials: D
authors.lastname: Mayo
authors.forename: V
authors.initials: V
authors.lastname: Santana
authors.forename: J
authors.initials: J
authors.lastname: Williamson
authors.forename: A
authors.initials: A
authors.lastname: Ciappa
authors.forename: H Z
authors.initials: HZ
authors.lastname: Rondon
authors.forename: P
authors.initials: P
authors.lastname: Estevez
authors.forename: R
authors.initials: R
authors.lastname: Lantigua
authors.forename: M
authors.initials: M
authors.lastname: Medrano
authors.forename: M
authors.initials: M
authors.lastname: Torres
authors.forename: Y
authors.initials: Y
authors.lastname: Stern
authors.forename: B
authors.initials: B
authors.lastname: Tycko
authors.forename: J A
authors.initials: JA
authors.lastname: Knowles
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000483:Alleles; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics*; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000235:genetics; D017691:Caribbean Region / Q000453:epidemiology; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D008126:Lod Score; D018895:Microsatellite Repeats / Q000235:genetics
chemical_list: D053327:Apolipoprotein E4; D001057:Apolipoproteins E