HbVar (http://globin.bx.psu.edu/hbvar) is one of the oldest and most appreciated 
locus-specific databases launched in 2001 by a multi-center academic effort to 
provide timely information on the genomic alterations leading to hemoglobin 
variants and all types of thalassemia and hemoglobinopathies. Database records 
include extensive phenotypic descriptions, biochemical and hematological 
effects, associated pathology and ethnic occurrence, accompanied by mutation 
frequencies and references. Here, we report updates to >600 HbVar entries, 
inclusion of population-specific data for 28 populations and 27 ethnic groups 
for α-, and β-thalassemias and additional querying options in the HbVar query 
page. HbVar content was also inter-connected with two other established genetic 
databases, namely FINDbase (http://www.findbase.org) and Leiden Open-Access 
Variation database (http://www.lovd.nl), which allows comparative data querying 
and analysis. HbVar data content has contributed to the realization of two 
collaborative projects to identify genomic variants that lie on different globin 
paralogs. Most importantly, HbVar data content has contributed to demonstrate 
the microattribution concept in practice. These updates significantly enriched 
the database content and querying potential, enhanced the database profile and 
data quality and broadened the inter-relation of HbVar with other databases, 
which should increase the already high impact of this resource to the globin and 
genetic database community.