Phenylketonuria is a human metabolic disease caused by mutat

Phenylketonuria is a human metabolic disease caused by mutations in the gene encoding the enzyme phcnylalanincammonia hydrolase (PAH). About 20% of mutant alleles for the human gene PAH have a CGG-to-TGG transition at bases 1222 - 1224 of the coding region. What is the proper designation of this PAH allelic variant? A. ARG408TRP B. ARG1222TRP C. CGG408TGG D. TGG408CGG E. C1222T

Solution

Option B.

CGG in coding region codes for arginine amino acid. TGG in coding region gives UGG in mRNA, which codes for tryptophan amino acid.

According to Mutation nomenclature, the designation should be \'original amino acid>nucleotide number in the coding sequence>new version of amino acid.

Therefore, Arg1222Trp