Identification of deletions and duplications in the low density lipoprotein receptor gene by MLPA

Background: Familial hypercholesterolemia (FH) is caused by mutations in the low density lipoprotein (LDL) receptor gene. In this study we have compared multiplex ligation-dependent probe amplification (MLPA) and long-range PCR to detect large deletions/duplications in the LDL receptor gene. Method: DNA from 431 unrelated FH patients without mutations in the LDL receptor gene detectable by DNA sequencing and who had total serum cholesterol levels above 10.0 mmol/l, was subjected to analyses by MLPA and by five long-range PCRs. Result: Eleven deletions and two duplications were detected by MLPA. Six of the deletions and one of the duplications were also detected by long-range PCR. A total of 44 of the 431 (10.2%) FH patients possessed a deletion or a duplication. Conclusion: MLPA has a higher sensitivity than five long-range PCRs to detect large deletions/duplications in the LDL receptor gene. Even though the direct cost of MLPA is twice that of five long-range PCRs, it has replaced long-range PCR for routine diagnostics in our laboratory because of the higher sensitivity and the 30-50% reduction in hands-on time. (c) 2005 Elsevier B.V. All rights reserved.