D1024 Nucleic Acids Research, 2012, Vol. 40, Database issue immunological reaction. The use of transfusion being ubi- quitous in the practice of medicine, populations world- wide are serologically tested and variant antigens and their genes, in contrast to many other variant genes are being documented in a large number of diverse popula- tions. Although some variants occur rarely and, may only be observed in a single individual or family, others appear in unexpectedly large populations, such as the MiIII phenotype encoded by the MiIII GYPA gene, in Taiwan (incidence can be as high as 88% among Ami tribes) (2). For many alleles, the database also provides information on the geographic or ethnic origin of alleles and/or their associated serological phenotypes when such information was presented in the publications describing the alleles. This may be of use to those interested in population migrations. HISTORY AND CURRENT STATE BGMUT was developed in 1999 as a locus-speciﬁc gene mutation database under the aegis of the Human Variation Genome Society. It was curated under the dir- ection of one of the authors (OOB) with original informa- tion contributed by more than a dozen blood group system experts. The database was hosted online by the Department of Biochemistry at the Albert Einstein College of Medicine, New York. BGMUT was identiﬁed as one of three model locus-speciﬁc databases from more than 200 in a scholarly review (3). In 2006, BGMUT became a part of the dbRBC resource of the NCBI. At dbRBC, curatorship and direction for maintenance of the database has been provided by another of the authors (WH). The number of alleles in BGMUT has ap- proximately doubled since 2004 when the database was ﬁrst described in a scholarly publication (4). This publica- tion has been referred to many times in the scientiﬁc lit- erature indicating that BGMUT has been a useful resource. Links to BGMUT database records are available on relevant pages of the Wikipedia online encyclopedia, and on many of NCBI’s online resources. BGMUT is also a part of the PhenCode project which attempts to inte- grate genetic variation data with the UCSC Genome Browser (5). As of August 2011, BGMUT had 1251 alleles belonging to 40 genes that are together responsible for 30 human blood group systems (Table 1). Alleles of some genes, such as ABO and RHCE/D which are, respectively, re- sponsible for the ABO and Rh blood group systems most frequently examined in the populations, are more numerous than those of others (Table 1). As per the International Society for Blood Transfusion, there are 30 human blood group systems (http://ibgrl.blood.co.uk/ ISBT%20Pages/ISBT%20Terminology%20Pages/Table %20of%20blood%20group%20systems.htm), all of which are covered by BGMUT. The Globoside (GLOB) system is currently considered a part of the P1PK system in BGMUT, which additionally considers the system of T and Tn antigens as a separate blood group system. DATABASE ARCHITECTURE BGMUT is accessible online for view, search or for ad- ministration as a website in the form of HTML (hyper-text markup language) pages (Figures 1 and 2). A Microsoft SQL Server relational database is used for data storage. Programmatic code in SQL (structured query language), C++ and XSLT (extensible structured language transformations) languages is used for inter- action with the SQL Server database and for rendering BGMUT’s web-based interface. Raw data on all or a subset of the alleles described in BGMUT can be down- loaded as tab-delimited or comma-separated (CSV) text formats from the BGMUT website. Compilations of allelic sequences for the ABO, H, MNS and Rh systems in the Microsoft Excel format are also available for download. DATABASE CURATION AND ALLELE SUBMISSION The BGMUT database is curated manually. Allelic infor- mation is periodically collated from scientiﬁc literature, as is the case for a majority of the alleles listed in BGMUT, or is obtained as direct submissions from researchers through the database website. During the process of curation, good quality of methods used in a study is as- certained. The new candidate allele’s sequence that has been published and/or submitted to a publicly available repository such as NCBI’s GenBank is compared to BGMUT’s reference allele for the gene sequence. The sequence positions and the kinds of the deduced amino acid changes are also veriﬁed. Authors are consulted in case of a question or disagreement. For direct submission of information on a new allele for inclusion in the database, a scientiﬁc publication describing the allele is not required. However, submitters are encouraged to deposit the allele’s sequence in a publicly available reposi- tory. In the absence of a scientiﬁc publication, this is a requirement. ALLELES IN BGMUT Alleles in BGMUT are grouped by the blood group system that the genes they belong to affect. For each allele in the database, BGMUT provides details on the nucleotide changes and the deduced amino acid changes in the protein encoded by the gene the allele belongs to. These changes are in context of a ‘reference’ allele that itself is included in BGMUT, and is the same for all alleles of a gene. Besides the information on the sequence changes, BGMUT also details for an allele the frequency of occur- rence, the associated blood group phenotype, references to the studies that identiﬁed and characterized the allele and accession numbers of the relevant sequences in NCBI GenBank when such information is available. GenBank accession numbers, however, are not available for many alleles because though they have been described in pub- lished literature, their sequences were not deposited in the repository by the authors. When known, the regions of the gene or cDNA that were sequenced to identify the allele, the prevalence of the allele in different geographical