A novel ARH splice site mutation in a Mexican kindred with autosomal recessive hypercholesterolemia.
Autosomal recessive hypercholesterolemia (ARH) is characterized by elevated LDL serum levels, xanthomatosis, and premature coronary artery disease. Three loci have been described for this condition (1p35, 15q25-q26 and 13q). Recently, the responsible gene at the 1p35 locus, encoding an LDL receptor adaptor protein (ARH) has been identified. We studied a Mexican ARH family with two affected siblings. Sequence analysis of the ARH gene (1p35 locus) revealed that the affected siblings are homozygous for a novel mutation (IVS4+2T>G) affecting the donor splice site in intron 4, whereas both the parents and an unaffected sister are heterozygous for this mutation. The IVS4+2T>G mutation results in a major alternative transcript derived from a cryptic splice site, which carries an in-frame deletion of 78 nucleotides in the mature mRNA. The translation of this mRNA yields a mutant protein product (ARH-26) lacking 26 amino acids, resulting in the loss of beta-strands beta6 and beta7 from the PTB domain. This is the first case where a naturally occurring mutant with an altered PTB domain has been identified.
Canizales-Quinteros
Samuel
S
Instituto de Investigaciones Biomédicas de la Universidad Nacional Autónoma de México e Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán", Vasco de Quiroga #15 Colonia Sección 16, Mexico City, 14000 Tlalpan, Mexico. cani@servidor.unam.mx
Aguilar-Salinas
Carlos A
CA
Huertas-Vázquez
Adriana
A
Ordóñez-Sánchez
María L
ML
Rodríguez-Torres
Maribel
M
Venturas-Gallegos
José L
JL
Riba
Laura
L
Ramírez-Jimenez
Salvador
S
Salas-Montiel
Rocío
R
Medina-Palacios
Giovani
G
Robles-Osorio
Ludivina
L
Miliar-García
Angel
A
Rosales-León
Luis
L
Ruiz-Ordaz
Blanca H
BH
Zentella-Dehesa
Alejandro
A
Ferré-D'Amare
Adrian
A
Gómez-Pérez
Francisco J
FJ
Tusié-Luna
Ma Teresa
MT
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000328:Adult; D000595:Amino Acid Sequence; D003241:Consanguinity; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D006937:Hypercholesterolemia / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008800:Mexico; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D017434:Protein Structure, Tertiary; D022821:RNA Splice Sites / Q000235:genetics*; D014973:Xanthomatosis / Q000235:genetics / Q000503:physiopathology
D048868:Adaptor Proteins, Signal Transducing; C469745:LDLRAP1 protein, human; D022821:RNA Splice Sites