In Gaucher disease patients, over 100 disease-causing mutations have been i
dentified. For identification of the 1504C --> T (R463C) mutation it is com
mon to use PCR-restriction fragmentation analysis using the restriction enz
yme MspI. In the present study we investigated the reliability of this appr
oach because accurate determination of genotypes is important in genotype-p
henotype correlations. A simple modification, i.e. using the restriction en
zyme HphI instead of MspI, revealed that type I and II Gaucher disease pati
ents who had previously been identified as carrying the 1504C --> T mutatio
n in fact carried the 1505G --> A (IVS10(-1) G --> A) mutation. Sequencing
of the appropriate fragment confirmed this. The PCR method easily different
iates between these two mutations in Gaucher disease patients, thus circumv
enting the need for sequencing procedures. The phenotypes of the patients f
ound to be carrying the 1505G-->A mutation are also described. (C) 2001 Els
evier Science B.V. All rights reserved.