"With this knowledge in hand, we hope to screen our patients and identify the genomic mechanism underlying this important disease," says Morrow.
Bernice Morrow, Ph.D.
Professor, Albert Einstein College of Medicine
Looking for genes in all the right places
Geneticists rely on variation, or alterations in DNA sequence, for disease-association studies. Hereditary traits such as heart disease, arthritis, and Alzheimer's can be assigned to specific genomic regions based on their association with DNA markers.
The success of disease-association studies is dependent upon several characteristics of the DNA markers, including allelic frequency and genomic coverage. In some cases, a particular variant at one locus is perfectly associated with a specific variant at another locus; in other words, the two markers are "genetically indistinguishable."
Dr. Lon Cardon and his colleagues describe in this month's issue of Genome Research how these "genetically indistinguishable" polymorphisms can complicate the identification of disease-related genes. "Although they should pose few difficulties when they are located close together on the same chromosome, they often occur on different chromosomes, where it is quite another story," explains Cardon. When this is the case, true disease genes cannot be distinguished from their anonymous genetic 'twins.'
"Research in human genetic variation is rapidly moving towards realizing our aims of improving diagnosis of comm
Source:Cold Spring Harbor Laboratory