Application of enzyme assay and gene analysis in the prenatal diagnosis for a family with glycogen storage disease type II / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To carry out prenatal diagnosis for a glycogen storage disease type II (GSD II ) affected family.</p><p><b>METHODS</b>The acid-α -glucosidase (GAA) activity was measured in whole leukocytes and cultured amniocytes with 4-methylumbelliferyl-α -D-glucopyranoside as substrate and with acarbose as inhibitor. The coding regions of GAA gene were amplified by polymerase chain reaction and analyzed by direct DNA sequencing.</p><p><b>RESULTS</b>The proband and the fetus had low GAA activity (12.3% and 1.1% of the average normal range, respectively). Mutation analysis of the GAA gene revealed a novel nonsense mutation p.W738X and a reported nonsense mutation p.E888X in both the proband and the fetus; the reported pseudodeficiency allele c.[1726G to A 2065G to A] was found in the proband, the mother and the fetus.</p><p><b>CONCLUSION</b>The proband and the fetus were both GSD II affected. A combination of GAA activity analysis and mutation analysis is efficient for the prenatal diagnosis of GSD II. Mutation analysis should be a routine method in the prenatal diagnosis of GSD II in Asian population, where pseudodeficiency allele can cause low GAA activity in normal individuals which is relatively common in Asian.</p>