12. This p.L483P (L444P) mutation was found in four different
haplotypes (Table 4).
Two novel mutations were identified. A novel non-synonymous
variant, c.1204T4C (p.Y402H), in exon 8 was found in patient 4
(Figure 1b middle panel and lower panel) and a novel termination
codon mutation, c.1609T4C (p.X537A) (Figure 1c middle panel and
lower panel), was found in patient 5. The boy was heterozygous for a
splice site mutation, IVS6-1G4C. Sequencing of his cDNA revealed
only the sequence of the p.X537A allele with no detectable level of the
IVS6-1G4C transcript (Figure 1c lower panel). Expression of the
p.X537A mutant and the wild-type clones in COS-7 cells demonstrated
that the mutation reduced the residual glucocerebrosidase
enzyme activity with respect to controls (Figure 2) and reduced the
protein expression level (Figure 3), but did not significantly change
the protein subcellular localization in mammalian cells (Figure 4).