Mgem. Ausems et al., Frequency of glycogen storage disease type II in The Netherlands: implications for diagnosis and genetic counselling, EUR J HUM G, 7(6), 1999, pp. 713-716
Glycogen storage disease type II (GSD II) is an autosomal recessive myopath
y, Early and late-onset phenotypes are distinguished - infantile, juvenile
and adult, Three mutations in the acid a-glucosidase gene are common in the
Dutch patient population: IVS1(-13F-->G), 525delT and delexon18 63% of Dut
ch GSD II patients carry one or two of these mutations, and the genotype-ph
enotype correlation is known, To determine the frequency of GSD II, we have
screened an unselected sample of neonates for the occurrence of these thre
e mutations. Based on the calculated carrier frequencies, the predicted fre
quency of the disease is 1 in 40 000 divided by 1 in 138 000 for infantile
G SD II and 1 in 57 000 for adult GSD II. This is about two to four times h
igher than previously suggested, which is a reason to become more familiar
with the presentation of GSD II in its different clinical forms and to adju
st the risk assessment for genetic counselling.