Pseudogenes, resulting from duplications of functional genes, contribute to the 
functional complexity of their parental genes. The glucocerebrosidase gene 
(GBA), located in a gene-rich region on chromosome 1q 21, is mutated in Gaucher 
disease. The presence of contiguous, highly homologous pseudogenes for both GBA 
and metaxin 1 at this locus increases the likelihood of DNA rearrangement. We 
describe a facile method to identify and analyze recombinant alleles in patients 
with Gaucher disease. Genomic DNA from 20 patients with recombinant GBA alleles 
and five controls was evaluated to identify DNA rearrangements or copy number 
variation using six probes specific for either the GBA gene or pseudogene. 
Quantitative real-time PCR was performed on genomic DNA, and Southern blot 
analyses using HincII together with sequencing confirmed the real-time results. 
Both GBA fusions and duplications could be detected. Different sites of 
crossover were identified, and alleles resulting from gene conversion could be 
distinguished from reciprocal recombinant alleles. Quantitative real-time PCR is 
a sensitive and rapid method to detect fusions and duplications in patients with 
recombinant GBA alleles. This technique is more sensitive, faster, and cheaper 
than Southern blot analysis, and can be used in diagnostic laboratories, and to 
detect other recombinant alleles within the genome.