Table 5. Linkage disequilibrium (LD) for pairs of KIR genes in HIV-1 negative and HIV-1 positive women, by placental malaria (PM) Status.
KIR2DL2 | KIR2DL3 | KIR2DS2 | ||||||||||||||
HIV+ | HIV− | African* | HIV+ | HIV− | African* | HIV+ | HIV | African* | ||||||||
PM− | PM+ | PM− | PM+ | PM− | PM+ | PM− | PM+ | PM− | PM+ | PM− | PM+ | |||||
KIR2DL1 | D | −0.0130 | −0.0160 | −0.0280 | – | −0.1900 | 0.0180 | 0.0290 | 0.0540 | – | 0.2100 | −0.0150 | −0.0100 | −0.0330 | – | −0.3400 |
D′ | −1.0000 | −1.0000 | −1.0000 | – | 0.7720 | 1.0000 | 1.0000 | – | −1.0000 | −0.5050 | −1.0000 | – | ||||
p | 0.0020 | 0.0830 | 0.0280 | – | <0.0001 | 0.0001 | 0.0004 | 0.0001 | – | <0.0001 | 0.0002 | 0.2990 | 0.0110 | – | <0.0001 | |
KIR2DL2 | D | −0.0570 | −0.1040 | −0.0690 | −0.0220 | −0.2700 | 0.1930 | 0.1980 | 0.1910 | 0.1930 | 0.1600 | |||||
D′ | −0.9550 | −1.0000 | −1.0000 | −1.0000 | 0.9230 | 0.9540 | 0.8990 | 0.9570 | ||||||||
p | 0.0001 | 0.0001 | 0.0001 | 0.0200 | <0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0100 | ||||||
KIR2DL3 | D | −0.0540 | −0.0870 | −0.0820 | −0.0260 | −0.2800 | ||||||||||
D′ | −0.7710 | −0.6950 | −1.0000 | −1.0000 | ||||||||||||
p | 0.0001 | 0.0001 | 0.0001 | 0.0050 | <0.0001 |
Classical coefficient D measures deviation from random association between the gene pairs, and D′ is given by D with the maximum value it can have [54]. ‘–’ denotes D value not determined due to monomorphism in one gene. LD was significant at P<0.002. African* is linkage disequilibrium cited from a previous population study [49].