Increased frequency of homozygosity of abnormal mannan-binding-protein alleles in patients with suspected immunodeficiency

Garred, Peter
Madsen, Hans O
Hofmann, Bo
Svejgaard, Arne

Tissue Typing Laboratory, Department of Clinical Immunology, National University Hospital (Rigshospitalet), DK-2200 Copenhagen, Denmark (P Garred MD, H O Madsen M Sci, B Hofmann MD, Prof A Svejgaard MD)
Correspondence to: Dr Peter Garred

The Lancet 346(8980):p 941-943, October 7, 1995.

A low plasma concentration of mannan-binding protein (MBP) impairs opsonisation and phagocytosis. Three different mutations in the MBP gene have a dominant effect on MBP concentration. We investigated the frequency of the abnormal MBP alleles in 228 unrelated patients suspected of various non-HIV-related immunodeficiencies. The frequency of heterozygotes for the abnormal alleles was not different from that in the background population (36.0 percent and 37.4 percent, respectively). By contrast, the frequency of homozygotes for the abnormal alleles was significantly increased (8.3 percent and 0.8 percent, respectively; p=0.0017). This finding implies that homozygotes for abnormal MBP alleles are predisposed to recurrent infections.

Lancet 1995; 346

941-43