Genetic characterization of myeloperoxidase deficiency in Italy

Hum Mutat. 2004 May;23(5):496-505. doi: 10.1002/humu.20027.

Abstract

Hereditary myeloperoxidase (MPO) deficiency (MPOD) is the most common neutrophil biochemical defect, and is characterized by a lack of peroxidase activity. In order to extend the epidemiological studies on hereditary MPOD in Italy, a population screening was carried out to detect mutations in the MPO gene. Of approximately 40,000 individuals analyzed, seven partial and eight total MPO-deficient subjects were identified. The genetic characterization of the subjects showed the presence of three already-known mutations (c.752T>C, c.1705C>T, and c.1566_1579del14) and six novel mutations: four missense mutations (c.995C>T, c.1112A>G, c.1715T>G, and c.1927T>C), then a deletion of an adenine within exon 3 (c.325delA) and a mutation within the 3' splice site of intron 11 (c.2031-2A>C). The novel missense mutations cause the substitution of the residues p.A332V, p.D371G, p.L572W, and p.W643R, respectively, and the potential structural changes are discussed. The c.325delA deletion causes a shift of the reading frame with the occurrence of a premature stop codon within the propeptide. Then, considering the difficulty in obtaining bone marrow samples from MPO-deficient subjects to study MPO mRNA splicing in vivo, we set up an eukaryotic expression system to investigate how the c.2031-2A>C mutation alters the MPO pre-mRNA splicing. The activation of a cryptic 3' splice site located 109nt upstream of the authentic 3' splice site was observed. The 109nt-insertion causes a shift in the reading frame that should lead to the generation of an abnormal MPO precursor lacking the enzymatic activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acid Substitution
  • Base Sequence
  • Deficiency Diseases / diagnosis
  • Female
  • Humans
  • Italy
  • Male
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation*
  • Mutation, Missense
  • Peroxidase / chemistry
  • Peroxidase / deficiency*
  • Peroxidase / genetics*
  • Point Mutation
  • RNA Splicing

Substances

  • Peroxidase

Associated data

  • OMIM/254600
  • OMIM/606989