Description and analysis of the Alpha 1 antitrypsin deficitary genotypes in the southwest area of Galicia (Spain)

Introduction: Alpha 1 antitrypsin deficiency (AATD) is a genetic condition that predisposes to the development of pulmonary emphysema and liver disease. Objectives: The aim of this study was to assess the characteristics of patients with AATD and the distribution of genotypes analyzed in the CHUVI Genetics Laboratory. Methods: Retrospective analysis of patients who underwent AAT levels determination between 2012-2017. Analysis of deficient alleles, frequency and distribution. Genetic study was performed in those cases with serum concentration of Alpha-1 antitrypsin ≤ 120 mg/dl and RCP ≤ 3 mg/dl (according to laboratory protocol). Results: 491 patients. Pi*ZZ genotype was found in 18 (3.7%), Pi*SZ in 100 (20.4%), Pi*MZ in 143 (29.1%), Pi*SS in 26 (5.3%) and No-Sno-Z in 174 (35,4%): 14 rare or null variants (6 Mmalton/M, 2 Mmalton/Z, 1 Mmalton/S, 1 S/QOurem, 1 S/MHerleen, 1 I/Z, 1 PLowell/S and 1 PLowell/Z), which were diagnosed by sequencing the gene. Serum levels were ZZ: 32 mg/dl (20-64), SZ: 66 mg/dl (42-120), MZ: 83 mg/dl (21-147), SS: 88 mg/dl (56-127) and No-S No-Z: 101 mg/dl (18-390). Conclusions: Genotypes associated with severe deficiency showed worse pulmonary function. Galicia is an area of relatively high prevalence of AATD, so this diagnostic possibility should be considered in the study of patients with diseases related to this genetic condition and in relatives of affected individuals.