Homozygosity mapping of Portuguese and Japanese forms of ataxia-oculomotor apraxia to 9p13, and evidence for genetic heterogeneity.

ABSTRACT: Ataxia with oculomotor apraxia (AOA) is characterized by early-onset cerebellar ataxia, ocular apraxia, early areflexia, late peripheral neuropathy, slow progression, severe motor handicap, and absence of both telangiectasias and immunodeficiency. We studied 13 Portuguese families with AOA and found that the two largest families show linkage to 9p, with LOD scores of 4.13 and 3.82, respectively, at a recombination fraction of 0. These and three smaller families, all from northern Portugal, showed homozygosity and haplotype sharing over a 2-cM region on 9p13, demonstrating the existence of both a founding event and linkage to this locus, AOA1, in the five families. Three other families were excluded from this locus, demonstrating nonallelic heterogeneity in AOA. Early-onset cerebellar ataxi

SUBMITTER: Moreira MC 

PROVIDER: S-EPMC1235299 | biostudies-literature | 2001 Feb

REPOSITORIES: biostudies-literature