On the basis of structural homology it has been proposed that the product of<unk> D gene, the<unk> D protein, is a membrane transport protein of uncertain specificity (CO2 or NH3) and unknown physiological role. The three-dimensional structure of the related<unk> CG protein and biochemical analysis of the<unk> D protein complex indicates that the<unk> D protein is one of three subunits of an ammonia transporter. Three recent studies have reported a protective effect of the<unk> D-positive phenotype, especially<unk> D heterozygosity, against the negative effect of latent toxoplasmosis on psychomotor performance in infected subjects.<unk> D-negative compared to<unk> D-positive subjects without anamnestic titres of anti-Toxoplasma antibodies have shorter reaction times in tests of simple reaction times. And conversely,<unk> D-negative subjects with anamnestic titres (i.e. with latent toxoplasmosis) exhibited much longer reaction times than their<unk> D-positive counterparts. The published data suggested that only the protection of<unk> D-positive heterozygotes was long term in nature; the protection of<unk> D-positive homozygotes decreased with duration of the infection while the performance of<unk> D-negative homozygotes decreased immediately after the infection. The overall change in reaction times was always larger in the<unk> D-negative group than in the<unk> D-positive.
Rh blood group system
Junior blood group system
Vel blood group
Hh blood group
Sid blood group system
Augustine blood group system
Lan blood group system
Indian blood group system