A two-base deletion in exon 6 of the 3-hydroxy-3- methylglutaryl coenzyme A lyase (HL) gene producing the skipping of exons 5 and 6 determines 3- hydroxy-3-methylglutaric aciduria
Author
Casals i Farré, Núria
Pié, Juan
Casale, César H.
Zapater, Núria
Ribes, Antònia
Castro-Gago, Manuel
Rodriguez-Segade, Santiago
Wanders, Ronald J. R.
Hegardt, Fausto G.
Publication date
1997ISSN
0022-2275
Abstract
A novel two-base deletion in the 3-hydroxy-3-methylglutaryl coenzyme A lyase (HL) gene was found in a Spanish patient with homozygous 3-hydroxy-3-methylglutaric aciduria. Amplification by RT-PCR of the mRNAs showed that the gene was transcribed into three different mRNAs. One showed the complete deletion of exons 5 and 6 located between nucleotides 348 and 561 of the HL cDNA. The second transcript showed deletion of exon 6 only, and the third contained a two-base deletion CT in exon 6, corresponding to nucleotides 504 and 505 of the HL cDNA. These aberrant mRNAs are predicted to encode three abnormal HMG-CoA lyase proteins; the first (from skipped exons 5 and 6) lacks 71 amino acids, which represents 24% of the mature protein; the second, (from the skipping of exon 6, producing a frameshift) contains only 192 amino acids, the last 26 of which are missense amino acids preceding a stop codon; the third contains only 175 amino acids, the last 7 of which are missense. Northern blot analysis showed that the HL mRNA levels of the patient were 4% of the control. PCR quantitative analysis indicated that the mRNA lacking exons 5 and 6 was the most abundant, representing 88% of the total. The other two mRNAs represented 8% and 4%, respectively. In the genomic DNA only one CT deletion was found at positions +7 and +8 at beginning of exon 6. No mutations were observed in the splice donor, splice acceptor, or pyrimidine-rich sequences of the intronic regions flanking exons 5 and 6. All three aberrant mRNAs resulted only from the deletion of nucleotides CT. We suggest that this deletion may affect the interaction between the small nuclear ribonucleoproteins (snRNPs) and exon 6, and that, as a result, the abnormal splicing of the pre-mRNA produces two different aberrant transcripts.
Document Type
Article
Document version
Published version
Language
English
Subject (CDU)
61 - Medical sciences
Keywords
Mutació (Biologia)
Genomes
Nucleòtids
Mutación (Biología)
Genomas
Nucleótidos
Mutation
Genomes
Nucleotides
Pages
11
Publisher
Elsevier
Collection
38; 11
Is part of
Journal of Lipid Research
Citation
Casals i Farré, Núria Pié, Juan Casale, Cesar H. [et al.]. A two-base deletion in exon 6 of the 3-hydroxy-3- methylglutaryl coenzyme A lyase (HL) gene producing the skipping of exons 5 and 6 determines 3- hydroxy-3-methylglutaric aciduria. Journal of Lipid Research, 1997, 38(11), p. 2303-2313. Disponible en: <https://www.jlr.org/article/S0022-2275(20)34944-0/abstract?sid=c436dc1d-3ad0-437d-9d41-155a0ac65bf5>. Fecha de acceso: 19 abr. 2021. DOI: 10.1016/S0022-2275(20)34944-0
This item appears in the following Collection(s)
- Ciències de la Salut [745]
Rights
This is an Open Access article under the CC BY license.
Except where otherwise noted, this item's license is described as https://creativecommons.org/licenses/by/4.0/