A novel missense mutation in human lactate dehydrogenase B-subunit gene

Mol Genet Metab. 2001 Aug;73(4):344-8. doi: 10.1006/mgme.2001.3203.

Abstract

Reduced activity of serum lactate dehydrogenase (LDH; EC 1.1.1.27) was found in a male medical student during practical examinations of his own blood. Serum LDH isoenzyme pattern showed reductions in activities of the isoenzymes with lower subunit A/B ratios such as LDH1 and LDH2. These findings were indicative of a partial LDH-B subunit deficiency, which was confirmed in erythrocyte hemolysates by Western blotting. Polymerase chain reaction (PCR)-based DNA sequence analysis of the LDH-B subunit gene revealed a heterozygous nucleotide change: a guanine to adenine substitution in codon 69 (GGG --> GAG) at the third exon of the LDH-B subunit gene that resulted in a glycine to glutamic acid substitution (G69E). The mutation was confirmed by PCR-restriction fragment length polymorphism (RFLP) analysis using a mismatched primer to introduce a new NcoI restriction site. The same heterozygous mutation was found in his mother but not in other family members. This mutation involves a residue belonging to alphaC helix in LDH-B subunit protein molecule that functions as an interface for other subunits.

MeSH terms

  • Adult
  • Base Sequence
  • Blotting, Western
  • Heterozygote
  • Humans
  • Isoenzymes / blood
  • Isoenzymes / chemistry
  • Isoenzymes / deficiency
  • Isoenzymes / genetics
  • L-Lactate Dehydrogenase / blood
  • L-Lactate Dehydrogenase / chemistry*
  • L-Lactate Dehydrogenase / deficiency
  • L-Lactate Dehydrogenase / genetics*
  • Male
  • Mutation, Missense / genetics*
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Protein Subunits

Substances

  • Isoenzymes
  • Protein Subunits
  • L-Lactate Dehydrogenase