MVarallo: A New MLike Alpha 1-Antitrypsin-Deficient Allele

A 73-year-old never-smoker woman with chronic bronchitis, increasing dyspnoea, and airflow limitation with a FEV1 of 49% of predicted value had low serum level of alpha-1-antitrypsin (69 mg/dL, normal range 150–350). Isoelectric focusing showed an Mlike pattern. Direct sequencing showed, in the second exon, a particular DNA alteration localized between codon 41 and codon 51a region of 30 base pairs (bp) was completely deleted and substituted by a 22-bp sequence. The resulting loss of 8 bp yields, in the second exon, a 70–71 stop codon. This new Mlike variant was denominated MVarallo from the site where it was discovered.