Increased frequency of homozygosity of abnormal mannan-binding-protein alleles in patients with suspected immunodeficiency.
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% and 37.4%, respectively). By contrast, the frequency of homozygotes for the abnormal alleles was significantly increased (8.3% and 0.8%, respectively; p = 0.0017). This finding implies that homozygotes for abnormal MBP alleles are predisposed to recurrent infections.
Garred
P
P
Department of Clinical Immunology, National University Hospital (Rigshospitalet), Copenhagen, Denmark.
Madsen
H O
HO
Hofmann
B
B
Svejgaard
A
A
D000483:Alleles; D002352:Carrier Proteins / Q000097:blood / Q000235:genetics*; D002675:Child, Preschool; D037222:Collectins; D005260:Female; D005787:Gene Frequency; D006720:Homozygote; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000097:blood / Q000235:genetics*; D007223:Infant; D008297:Male
D002352:Carrier Proteins; D037222:Collectins