Interviewee: Matt Ridley. Alzheimer disease (AD) has been linked with mutations in four genes that are situated on chromosomes 1, 14, 19 and 21. Although Alzheimer disease appears to be caused by mutations in genes on chromosomes 14 and 21, an interesting association to the APOE gene has been linked with Alzheimer disease. (DNAi Location: Genome > Tour > Genome spots > Chromosome 19: Alzheimer disease > A chromosome 19 story)

On chromosome 19 there's a gene of enormous medical significance; it's called the APOE gene. It's 897 letters of DNA text long, and the 334th letter is usually an A, but in some of us it's a G. In those people with that single tiny change, there is a greater likelihood that they will get Alzheimer's in later life." +" Now how do we handle this kind of information? It doesn't mean that these people will definitely get Alzheimer's, so giving the genetic test to such people in the hope of predicting their fate, would perhaps be misleading. It's only a small proportion of them that will get the disease. It's very difficult to know when diagnosis is running ahead of cure in this way and how to deal with these kind of medical dilemmas.

apoe gene,matt ridley,dna text,chromosome 1,medical dilemmas,apolipoprotein e,medical significance,alzheimer disease,tiny change,dnai,ad4,genetic test,ad3,gene name,interviewee,chromosomes,mutations,ps1,susceptibility,genes