Clinical implications of the SERPINA1 variant, MPalermo, and alpha-1 antitrypsin deficiency in Türkiye

Abstract

Background: Alpha-1 antitrypsin deficiency (AATD) is associated with increased susceptibility to chronic obstructive pulmonary disease (COPD). AATD results from mutations in the SERPINA1 gene and over 500 rare mutations have been identified. Despite these findings and recommendations from major healthcare organizations, testing of COPD patients and their family members for AATD remains inadequate. Methods: We examined genotypes and clinical characteristics of COPD patients (index cases; n = 14) treated at Recep Tayyip Erdoğan University Chest Diseases Department and their relatives (n = 17). Results: When index cases were compared with screened relatives positive for AATD (n = 14), index cases were older and more predominantly male than screened relatives. Both groups had extensive smoking histories. All of the index cases and one of the screened relatives had been diagnosed with COPD. Clinical characterization of the COPD cases (14 index cases; 1 screened relative) showed that they had moderate to severe COPD with pre-treatment AAT levels of 0.59 ± 0.40 g/L (mean ± SD) and a COPD Assessment Test (CAT) score of 16.0 ± 8.12. The majority of these patients (73.3%) had panlobular emphysema. Five of the patients were treated with AAT augmentation which led to a decrease in the number of COPD exacerbations. Genotyping revealed that the most common rare allele identified in this population was MPalermo (c.227_229delTCT mutation on the M1(Val213) allelic background). Conclusions: More testing and research need to be done to identify the relative prevalence of rare AATD variants. Earlier identification could lead to more effective treatment of affected individuals and improvement in their quality of life.