title: What is Pi (proteinase inhibitor) null or PiQO?: a problem highlighted by the alpha 1 antitrypsin Mheerlen mutation.
abstract: alpha 1 antitrypsin deficiency is associated with predisposition to the development of pulmonary emphysema and childhood cirrhosis. There are two common deficiency alleles in the European population, proteinase inhibitor (Pi) Z and S. In addition, there are rare Pinull or QO variants which can be difficult to diagnose. A family assigned as having the PiQO allele by AAT protein quantification and isoelectric focusing was shown by DNA sequencing to have the PiMheerlen mutation (Pro369-Leu). This highlights the difficulties of diagnosis of PiQO.
authors.affiliation: Department of Medical Biochemistry, University of Wales College of Medicine, Royal Infirmary, Cardiff.
authors.forename: N
authors.initials: N
authors.lastname: Kalsheker
authors.forename: K
authors.initials: K
authors.lastname: Hayes
authors.forename: S
authors.initials: S
authors.lastname: Weidinger
authors.forename: A
authors.initials: A
authors.lastname: Graham
mesh_terms: D000483:Alleles; D003062:Codon / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D000515:alpha 1-Antitrypsin / Q000235:genetics*; D019896:alpha 1-Antitrypsin Deficiency
chemical_list: D003062:Codon; D000515:alpha 1-Antitrypsin