Linkage relationship between the genes for adenosine deaminase and S-adenosyl-homocysteine hydrolase on human chromosome 20.

The genes for adenosine deaminase (ADA) and S-adenosyl homocysteine hydrolase (AHCY or SAHH) are known to be syntenic and within measurable distance from each other, on chromosome 20 in man. In the present study an informative family is described in which the recombination fraction (theta) between the respective genes is estimated to be about 0.18. Together with the published finding of theta = 0.15 (Eiberg and Mohr 1985) in informative Danish families, the recombination fraction for the pooled data is calculated to be theta = 0.14 (in men), theta = 0.08 (in women) and theta = 0.13 (both sexes taken together).