Scientists have classified which alleles of a mutated enzyme can benefit from changes in diet, in a new yeast study published last week (April 1) in Genetics. Mutations in the cystathionine-ß-synthase (CBS) enzyme can lead to a variety of diseases, such as mental retardation and homocystinuria. Some patients benefit from supplementing their diet with vitamin B6, a cofactor that aids CBS’s enzymatic activity, but it depends on which mutation they carry.
To identify the CBS mutations whose resulting diseases could be aided by diet, scientists from the University of California, Berkeley, expressed different alleles of the human CBS gene in yeast that were missing the CBS ortholog Cys4p. They then measured yeast growth and enzyme activity with and without vitamin B6 or heme, another CBS cofactor.
The researchers were able to successfully sort alleles based on response to cofactor supplementation, which will help doctors identify which patients will respond well to early dietary interventions.
“This study moves us a step closer toward better understanding the genetic variability among people,” Mark Johnston, editor-in-chief of the journal Genetics, said in a press release. “More immediately, knowledge of these gene mutations will help physicians prescribe treatment based on genotype rather than outward symptoms or trial and error.”