BTKBASE, MUTATION DATABASE FOR X-LINKED AGAMMAGLOBULINEMIA (XLA)

X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by mut ations in the gene coding for Bruton's agammaglobulinemia tyrosine kin ase (BTK). A database (BTKbase) of BTK mutations has been compiled and the recent update lists 225 entries from 189 unrelated families showi ng 148 unique molecular events. Each patient is given a unique patient identity number (PIN). Information is included regarding the phenotyp e including symptoms. Mutations in all the five domains of BTK have be en noticed to cause the disease, the most common event being missense mutations. The mutations appear almost uniformly throughout the molecu le and frequently affect CpG sites forming arginine residues. A decrea sed frequency of missense mutations was found in the TH, SH3 and upper lobe of the kinase domain. The putative structural implications of al l the missense mutations are given in the database.