A benign polymorphism in the aspartoacylase gene may cause misinterpretation of Canavan gene testing.
We found normal individuals whose aspartoacylase gene Y231X mutation site consistently gave no signal in a primer extension assay. We determined the nucleotide sequence of the relevant region of the gene in those individuals, and found a new allele with a thymidine residue at the mutation site instead of a cytidine. Since both TAC and TAT code for tyrosine, this sequence polymorphism has no effect on the amino acid sequence of the ASPA protein. We found the relative frequencies of the 693C and the 693T alleles in the tested population to be 0.75 and 0.25 respectively.
Propheta
O
O
GamidaGen Ltd, Nes Tsiona, Israel.
Magal
N
N
Shohat
M
M
Eyal
N
N
Navot
N
N
Horowitz
M
M
D000581:Amidohydrolases / Q000235:genetics*; D017825:Canavan Disease / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D009154:Mutation; D011110:Polymorphism, Genetic; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic; D000581:Amidohydrolases; C019751:aspartoacylase