Granularity of SERPINA1 alleles by DNA sequencing in CanCOLD

Gupta, Nisha, et al. European Respiratory Journal, 2020.

Key findings:

Poor sleep quality in individuals with COPD is associated with risk of symptom-based (dyspnea or sputum change ≥ 48 h) and event-based (symptoms plus medication or unscheduled health services use) COPD exacerbations.

Background: Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited condition characterized by low AAT serum concentrations and is associated with an accelerated rate of lung function decline, early onset emphysema and an increased risk of Chronic Obstructive Pulmonary Disease (COPD). AATD is caused by genetic mutations in the SERPINA1 gene. DNA sequencing provides a complete assessment of the mutated gene by detecting its conventional mutated alleles and its rare and novel genetic variants. Little is known about how common these deficient alleles are in the Canadian population and their individual and cumulative impacts on COPD phenotypes including lung function decline and emphysema.

What this study adds: This study shows that 15.5% of individuals of the CanCOLD cohort were carriers of at least one deficient allele affecting AAT serum levels. CanCOLD participants with genotypes resulting in severe AATD were more susceptible to develop airway obstruction, as demonstrated by lower lung function and greater emphysema. This study also shows the feasibility of DNA sequencing on a large scale to provide an accurate and definitive diagnosis for AATD. Results emphasize the advantages of genotype screening, which include allowing clinicians to make more informed treatment decisions based on more personalized risk prediction and helping to reduce the reported under-diagnosing of alpha-1-antitrypsin deficiency.