Functionally defective germline variants of sialic acid acetylesterase in autoimmunity
Ira Surolia, Stephan P. Pirnie, Vasant Chellappa, Kendra N. Taylor, Annaiah Cariappa, Jesse Moya, Haoyuan Liu, Daphne W. Bell, David R. Driscoll, Sven Diederichs, Khaleda Haider, Ilka Netravali, Sheila Le, Roberto Elia, Ethan Dow, Annette Lee, Jan Freudenberg, Philip L. De Jager, Yves Chretien, Ajit Varki, Marcy E. MacDonald, Tammy Gillis, Timothy W. Behrens, Donald Bloch, Deborah Collier, Joshua Korzenik, Daniel K. Podolsky, David Hafler, Mandakolathur Murali, Bruce Sands, John H. Stone, Peter K. Gregersen & Shiv Pillai
Nature (2010) Published online 16 June 2010 doi:10.1038/nature09115
Sialic acid acetylesterase (SIAE) is an enzyme that negatively regulates B lymphocyte antigen receptor signalling and is required for the maintenance of immunological tolerance in mice. Heterozygous loss-of-function germline rare variants and a homozygous defective polymorphic variant of SIAE were identified in 24/923 subjects of European origin with relatively common autoimmune disorders and in 2/648 controls of European origin. All heterozygous loss-of-function SIAE mutations tested were capable of functioning in a dominant negative manner. A homozygous secretion-defective polymorphic variant of SIAE was catalytically active, lacked the ability to function in a dominant negative manner, and was seen in eight autoimmune subjects but in no control subjects. The odds ratio for inheriting defective SIAE alleles was 8.6 in all autoimmune subjects, 8.3 in subjects with rheumatoid arthritis, and 7.9 in subjects with type I diabetes. Functionally defective SIAE rare and polymorphic variants represent a strong genetic link to susceptibility in relatively common human autoimmune disorders.