α1-Antitrypsin (Alpha-1-Proteinase-Inhibitor) (1-point-calibration) ELISA Kit

We report the development of a flexible database management system, based on a relational database format, for locus-specific database development and curation and its implementation for the development of a new locus-specific database, namely A(1)ATVar, for SERPINA1 gene variants, leading to alpha(1)-antitrypsin deficiency (available from http://www.goldenhelix.org/a1atvar). This tool allows data entry and display of mutation summaries in a tabular format, while user-generated queries can be formulated based on fields in the database table. A separate module, linked to FINDbase database for frequencies of inherited disorders allows the user to access relevant allele frequency information in different populations worldwide. Available experimental protocols to detect variant alleles at the protein and DNA levels can also be archived in a searchable format. A visualization tool, called VariVis, is implemented to combine variant information with gene sequence and annotation data. Finally, a direct data submission tool allows registered users to submit data on novel variant alleles as well as experimental protocols via a password-protected interface. Implementation of this tool is free of charge and there are no registration requirements for data querying. This database management system can serve as an example for an all-in-one solution for locus-specific database development and curation.

Background: Alpha-1 antitrypsin (AAT) is the most abundant circulating antiprotease and is a member of the serine protease inhibitor (SERPIN) superfamily. The gene encoding AAT is the highly polymorphic SERPINA1 gene, found at 14q32.1. Mutations in the SERPINA1 gene can lead to AAT deficiency (AATD) which is associated with a substantially increased risk of lung and liver disease. The most common pathogenic AAT variant is Z (Glu342Lys) which causes AAT to misfold and polymerise within hepatocytes and other AAT-producing cells. A group of rare mutations causing AATD, termed Null or Q0, are characterised by a complete absence of AAT in the plasma. While ultra rare, these mutations confer a particularly high risk of emphysema. Methods: We performed the determination of AAT serum levels by a rate immune nephelometric method or by immune turbidimetry. The phenotype was determined by isoelectric focusing analysis on agarose gel with specific immunological detection. DNA was isolated from whole peripheral blood or dried blood spot (DBS) samples using a commercial extraction kit. The new mutations were identified by sequencing all coding exons (II-V) of the SERPINA1 gene. Results: We have found eight previously unidentified SERPINA1 Null mutations, named: Q0(cork), Q0(perugia), Q0(brescia), Q0(torino), Q0(cosenza), Q0(pordenone), Q0(lampedusa), and Q0(dublin). Analysis of clinical characteristics revealed evidence of the recurrence of lung symptoms (dyspnoea, cough) and lung diseases (emphysema, asthma, chronic bronchitis) in M/Null subjects, over 45 years-old, irrespective of smoking. Conclusions: We have added eight more mutations to the list of SERPINA1 Null alleles. This study underlines that the laboratory diagnosis of AATD is not just a matter of degree, because the precise determination of the deficiency and Null alleles carried by an AATD individual may help to evaluate the risk for the lung disease.