Detection of large deletions in the LDL receptor gene with quantitative PCR methods

BACKGROUND: Familial Hypercholesterolemia (FH) is a common genetic disease and at the molecular level most often due to mutations in the LDL receptor gene. In genetically heterogeneous populations, major structural rearrangements account for about 5% of patients with LDL receptor gene mutations. METHODS: In this study we tested the ability of two different quantitative PCR methods, i.e. Real-Time PCR and Multiplex Ligation-Dependent Probe Amplification (MLPA), to detect deletions in the LDL receptor gene. We also reassessed the contribution of major structural rearrangements to the mutational spectrum of the LDL receptor gene in Denmark. RESULTS: With both methods it was possible to discriminate between one and two copies of the LDL receptor gene exon 5, but the MLPA method was cheaper, and it was far more accurate and precise than Real-Time PCR. In five of 318 patients with an FH phenotype, MLPA analysis revealed five different deletions in the LDL receptor gene. CONCLUSION: The MLPA method was accurate, precise and at the same time effective in screening a large number of FH patients for large deletions in the LDL receptor gene

Genomic characterization of five deletions in the LDL receptor gene in Danish Familial Hypercholesterolemic subjects

BACKGROUND: Familial Hypercholesterolemia is a common autosomal dominantly inherited disease that is most frequently caused by mutations in the gene encoding the receptor for low density lipoproteins (LDLR). Deletions and other major structural rearrangements of the LDLR gene account for approximately 5% of the mutations in many populations. METHODS: Five genomic deletions in the LDLR gene were characterized by amplification of mutated alleles and sequencing to identify genomic breakpoints. A diagnostic assay based on duplex PCR for the exon 7 – 8 deletion was developed to discriminate between heterozygotes and normals, and bioinformatic analyses were used to identify interspersed repeats flanking the deletions. RESULTS: In one case 15 bp had been inserted at the site of the deleted DNA, and, in all five cases, Alu elements flanked the sites where deletions had occurred. An assay developed to discriminate the wildtype and the deletion allele in a simple duplex PCR detected three FH patients as heterozygotes, and two individuals with normal lipid values were detected as normal homozygotes. CONCLUSION: The identification of the breakpoints should make it possible to develop specific tests for these mutations, and the data provide further evidence for the role of Alu repeats in intragenic deletions

Detection of large deletions in the LDL receptor gene with quantitative PCR methods-2

<p><b>Copyright information:</b></p><p>Taken from "Detection of large deletions in the LDL receptor gene with quantitative PCR methods"</p><p>BMC Medical Genetics 2005;6():15-15.</p><p>Published online 20 Apr 2005</p><p>PMCID:PMC1087844.</p><p>Copyright © 2005 Damgaard et al; licensee BioMed Central Ltd.</p> with the deletions described in the results section

Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia-0

<p><b>Copyright information:</b></p><p>Taken from "Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia"</p><p>BMC Medical Genetics 2005;6():6-6.</p><p>Published online 8 Feb 2005</p><p>PMCID:PMC551615.</p><p>Copyright © 2005 Zakharova et al; licensee BioMed Central Ltd.</p>t allele is shown at the bottom

Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia-1

<p><b>Copyright information:</b></p><p>Taken from "Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia"</p><p>BMC Medical Genetics 2005;6():6-6.</p><p>Published online 8 Feb 2005</p><p>PMCID:PMC551615.</p><p>Copyright © 2005 Zakharova et al; licensee BioMed Central Ltd.</p>ion. restriction enzyme test enables to confirm the presence of mutation Q12X identified by DNA sequencing in the proband (12-1) and in her son (12-2) and to exclude presence of the mutation in other relatives of the proband, including daughter (12-4) and grandchildren (12-3 and 12-5). Lengths of DNA restriction fragment are given at the left in bp and *total blood serum cholesterol figures of the patients – at the bottom of the gel in mg/dl

Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia-2

<p><b>Copyright information:</b></p><p>Taken from "Familial hypercholesterolemia in St.-Petersburg: the known and novel mutations found in the low density lipoprotein receptor gene in Russia"</p><p>BMC Medical Genetics 2005;6():6-6.</p><p>Published online 8 Feb 2005</p><p>PMCID:PMC551615.</p><p>Copyright © 2005 Zakharova et al; licensee BioMed Central Ltd.</p>fragment and in formation of specific heteroduplexes (indicated by A). Letter B indicates the PCR product of normal size. Current gel supports the presence of c.1291-1331del41 mutation in two children (3-2, 3-3) of the proband (3-1) and absence of this mutation in his daughter and grandson (3–4, 3–5). *total blood serum cholesterol figures of the patients – at the bottom of the gel in mg/dl