dear editor analysis of the phenylalanine hydroxylase (pah mckusick 261600) gene in different populations has revealed more than 320 different mutations associated with phenylketonuria (pku). one of these mutations, ivs10nt546, results in severe pah deficiency due to defective mrna splicing. it accounts for about 40 percent of all mutant alleles in turkish and between 10 to 20 percent of all mu...

Disorder in re-methylation process of homocysteine to methionine due to mutation in betaine homocysteine methyltransferase enzyme (BHMT) coding gene, leads to decrease in S-adenosyl methionine (SAM) synthesis which takes part in DNA methylation as a methyl donor. As a result, it can promote hypo-methylation of DNA, chromosome instability, and chromosome missegregation, which in turn is one of t...