Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum

Susana Seixas,1,2 Patricia Isabel Marques1,2 1i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; 2Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, PortugalCor...

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Main Authors: Seixas S, Marques PI
Format: Article
Language:English
Published: Dove Medical Press 2021-03-01
Series:The Application of Clinical Genetics
Subjects:
Online Access:https://www.dovepress.com/known-mutations-at-the-cause-of-alpha-1-antitrypsin-deficiency-an-upda-peer-reviewed-article-TACG
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author Seixas S
Marques PI
author_facet Seixas S
Marques PI
author_sort Seixas S
collection DOAJ
description Susana Seixas,1,2 Patricia Isabel Marques1,2 1i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; 2Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, PortugalCorrespondence: Susana Seixasi3S, Rua Alfredo Allen, 208, Porto, 4200-135, PortugalTel +351 220408806Email sseixas@ipatimup.ptAbstract: Alpha-1-Antitrypsin deficiency (AATD), caused by SERPINA1 mutations, is one of the most prevalent Mendelian disorders among individuals of European descend. However, this condition, which is characterized by reduced serum levels of alpha-1-antitrypsin (AAT) and associated with increased risks of pulmonary emphysema and liver disease in both children and adults, remains frequently underdiagnosed. AATD clinical manifestations are often correlated with two pathogenic variants, the Z allele (p.Glu342Lys) and the S allele (p.Glu264Val), which can be combined in severe ZZ or moderate SZ risk genotypes. Yet, screenings of AATD cases and large sequencing efforts carried out in both control and disease populations are disclosing outstanding numbers of rare SERPINA1 variants (> 500), including many pathogenic and other likely deleterious mutations. Generally speaking, pathogenic variants can be subdivided into either loss- or gain-of-function according to their pathophysiological effects. In AATD, the loss-of-function is correlated with an uncontrolled activity of elastase by its natural inhibitor, the AAT. This phenomenon can result from the absence of circulating AAT (null alleles), poor AAT secretion from hepatocytes (deficiency alleles) or even from a modified inhibitory activity (dysfunctional alleles). On the other hand, the gain-of-function is connected with the formation of AAT polymers and their switching on of cellular stress and inflammatory responses (deficiency alleles). Less frequently, the gain-of-function is related to a modified protease affinity (dysfunctional alleles). Here, we revisit SERPINA1 mutation spectrum, its origins and population history with a greater emphasis on variants fitting the aforementioned processes of AATD pathogenesis. Those were selected based on their clinical significance and wider geographic distribution. Moreover, we also provide some directions for future studies of AATD clinically heterogeneity and comprehensive diagnosis.Keywords: SERPINA1 variants, Z allele, S allele, MMalton allele and QOurém allele
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spelling doaj.art-5fd9af389795481b89512de3f960ba2c2022-12-21T21:56:26ZengDove Medical PressThe Application of Clinical Genetics1178-704X2021-03-01Volume 1417319463290Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation SpectrumSeixas SMarques PISusana Seixas,1,2 Patricia Isabel Marques1,2 1i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; 2Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, PortugalCorrespondence: Susana Seixasi3S, Rua Alfredo Allen, 208, Porto, 4200-135, PortugalTel +351 220408806Email sseixas@ipatimup.ptAbstract: Alpha-1-Antitrypsin deficiency (AATD), caused by SERPINA1 mutations, is one of the most prevalent Mendelian disorders among individuals of European descend. However, this condition, which is characterized by reduced serum levels of alpha-1-antitrypsin (AAT) and associated with increased risks of pulmonary emphysema and liver disease in both children and adults, remains frequently underdiagnosed. AATD clinical manifestations are often correlated with two pathogenic variants, the Z allele (p.Glu342Lys) and the S allele (p.Glu264Val), which can be combined in severe ZZ or moderate SZ risk genotypes. Yet, screenings of AATD cases and large sequencing efforts carried out in both control and disease populations are disclosing outstanding numbers of rare SERPINA1 variants (> 500), including many pathogenic and other likely deleterious mutations. Generally speaking, pathogenic variants can be subdivided into either loss- or gain-of-function according to their pathophysiological effects. In AATD, the loss-of-function is correlated with an uncontrolled activity of elastase by its natural inhibitor, the AAT. This phenomenon can result from the absence of circulating AAT (null alleles), poor AAT secretion from hepatocytes (deficiency alleles) or even from a modified inhibitory activity (dysfunctional alleles). On the other hand, the gain-of-function is connected with the formation of AAT polymers and their switching on of cellular stress and inflammatory responses (deficiency alleles). Less frequently, the gain-of-function is related to a modified protease affinity (dysfunctional alleles). Here, we revisit SERPINA1 mutation spectrum, its origins and population history with a greater emphasis on variants fitting the aforementioned processes of AATD pathogenesis. Those were selected based on their clinical significance and wider geographic distribution. Moreover, we also provide some directions for future studies of AATD clinically heterogeneity and comprehensive diagnosis.Keywords: SERPINA1 variants, Z allele, S allele, MMalton allele and QOurém allelehttps://www.dovepress.com/known-mutations-at-the-cause-of-alpha-1-antitrypsin-deficiency-an-upda-peer-reviewed-article-TACGserpina1 variantsz alleles allelemmalton allele and qourém allele
spellingShingle Seixas S
Marques PI
Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
The Application of Clinical Genetics
serpina1 variants
z allele
s allele
mmalton allele and qourém allele
title Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
title_full Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
title_fullStr Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
title_full_unstemmed Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
title_short Known Mutations at the Cause of Alpha-1 Antitrypsin Deficiency an Updated Overview of SERPINA1 Variation Spectrum
title_sort known mutations at the cause of alpha 1 antitrypsin deficiency an updated overview of serpina1 variation spectrum
topic serpina1 variants
z allele
s allele
mmalton allele and qourém allele
url https://www.dovepress.com/known-mutations-at-the-cause-of-alpha-1-antitrypsin-deficiency-an-upda-peer-reviewed-article-TACG
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