부산대학교 도서관

Considerable research evidence has been amassed that implicates human chromosome 21 in Alzheimer's disease (AD), a progressive neurological disorder leading to complete cognitive loss, but the aberrant gene has yet to be identified. Although the gene that encodes the amyloid precursor protein (APP), a protein from which beta-amyloid protein (an abnormal substance found in the brains of people with AD) is made, has been suspected, evidence that recombination events take place between the APP gene and the probable AD locus argues against this. A series of experiments is reported in which APP DNA from a family member with early-onset AD was analyzed along its entire length to determine the AD locus. A point mutation (a mutation in a single base) was found in exon 17, a region chosen first for sequencing because it encodes part of the beta-amyloid protein and is known to contain a mutation in another hereditary cerebral disease. The same mutation was found in other members of the same kindred, and in another unrelated family with early-onset disease. No such mutation was found in 100 normal individuals, or in families with late-onset disease. If these results are valid, the APP gene in other families should show a similar mutation. (Consumer Summary produced by Reliance Medical Information, Inc.)