Functional analysis of LDLR promoter and 5′ UTR mutations in subjects with clinical diagnosis of familial hypercholesterolemia

• Published in: Human mutation Vol. 32; no. 8; pp. 868 - 872
• Main Authors: De Castro-Orós, Isabel, Pampín, Sandra, Bolado-Carrancio, Alfonso, De Cubas, Aguirre, Palacios, Lourdes, Plana, Nuria, Puzo, Jose, Martorell, Esperanza, Stef, Marianne, Masana, Luis, Civeira, Fernando, Rodríguez-Rey, Jose Carlos, Pocoví, Miguel
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.08.2011; John Wiley & Sons, Inc
• Subjects: 5' Untranslated Regions - genetics; 5′ UTR; Base Sequence; Cell Line, Tumor; Consensus Sequence - genetics; Data processing; Electrophoretic Mobility Shift Assay; familial hypercholesterolemia; Hep G2 Cells; Hereditary diseases; Humans; Hypercholesterolemia; Hyperlipoproteinemia Type II - genetics; LDLR; LDLR gene; Lipoprotein (low density) receptors; Molecular Sequence Data; Mutation; Mutation - genetics; promoter; Promoter Regions, Genetic - genetics; Promoters; Receptors, LDL - genetics; Regulatory sequences
• ISSN: 1059-7794; 1098-1004; 1098-1004
• DOI: 10.1002/humu.21520

Familial hypercholesterolemia (FH) is a dominant disorder due to mutations in the LDLR gene. Several mutations in the LDLR promoter are associated with FH. Screening of 3,705 Spanish FH patients identified 10 variants in the promoter and 5′ UTR. Here, we analyse the functionality of six newly identified LDLR variants. Mutations located in the LDLR promoter regulatory elements R2 and R3 (c.−155_‐150delACCCCinsTTCTGCAAACTCCTCCC, c.−136C>G, c.−140C>G, and c.−140C>T) resulted in 6 to 15% residual activity in reporter expression experiments and changes in nuclear protein binding affinity compared to wild type. No reduction was observed when cells were transfected with c.−208T, c.−88A, and c.−36G mutant fragments. Our results indicate that mutations localized in R2 and R3 are associated with hypercholesterolemia, whereas mutations outside the LDLR response elements are not a cause of FH. This data emphasizes the importance of functional analysis of variants in the LDLR promoter to determine their association with the FH phenotype.Hum Mutat 32:1–5, 2011. © 2011 Wiley‐Liss, Inc.