The effect of a single base pair deletion (ΔT525) and a C1634T missense mutation (pro545leu) on the expression of lysosomal α-glucosidase in patients with glycogen storage disease type II

Glycogen storage disease type II (GSDII, Pompe's disease) is caused by an autosomal recessive inheritance of lysosomal α-glucosidase deficiency. By sequence analysis we have identified the mutations in the lysosomal α-glucosidase gene (GAA) of two unrelated patients, who have one and two copies, respectively, of the same missense mutation. The milder affected adult patient was found to be homozygous for a C1634T transition resulting in the substitution of pro545 by leu. The more severely attected adolescent patient had this same mutant allele combined with a 1 base pair deletion (ΔT525) in the second allele causing premature termination at nucleotide positions 658-660