Table 4. Contribution of HLA class II and non-HLA genes towards heritability of antibody responses to blood stage antigens in adult twins.
| Antibody | Antigens | r, HLA identical MZ (n = 58) | r, HLA identical DZ (n = 38) | r, HLA non-identical MZ (n = 117) | Contribution by non-HLA class II genes h 2 (95% CI) | Contribution by HLA class II genes h 2 (95% CI) |
| IgG1 | AMA1 | 0.70 | 0.61 | 0.55 | 0.18 (0.0–0.65) | 0.17 (0.0–0.55) |
| MSP1-19 | 0.61 | 0.24 | 0.41 | 0.63 (0.24–0.76) | 0 (0.0–0.27) | |
| MSP3A | 0.77 | 0.33 | 0.35 | 0.77 (0.42–0.85) | 0 (0.0–0.50) | |
| MSP3B | 0.68 | 0.37 | 0.53 | 0.68 (0.17–0.80) | 0 (0.0–0.24) | |
| IgG2 | MSP2A | 0.70 | 0.48 | 0.39 | 0.67 (0.13–0.77) | 0 (0.0–0.35) |
| MSP3B | 0.64 | 0.05 | 0.31 | 0.55 (0.0–68) | 0 (0.0–0.54) | |
| IgG3 | AMA1 | 0.53 | 0.41 | 0.34 | 0.53 (0.0–0.75) | 0.05 (0.0–0.55) |
| MSP2A | 0.72 | 0.53 | 0.35 | 0.27 (0.0–0.76) | 0.33 (0.0–0.68) | |
| MSP3A | 0.62 | 0.25 | 0.33 | 0.58 (0.0–0.72) | 0 (0.0–0.53) | |
| IgG4 | AMA1 | 0.44 | 0.21 | 0.11 | 0.46 (0.0–0.65) | 0.28 (0.0–0.55) |
| MSP2A | 0.58 | 0.60 | 0.33 | 0.11 (0.0–0.66) | 0.47 (0.0–0.71) | |
| MSP2B | 0.72 | 0.02 | 0.48 | 0.73 (0.52–0.83) | 0 (0.0–0.16) | |
| MSP3A | 0.58 | 0.36 | 0.55 | 0.63 (0.14–0.75) | 0 (0.0–0.23) | |
| IgA | AMA1 | 0.55 | 0.35 | 0.14 | 0.60 (0.03–0.74) | 0.30 (0.0–0.51) |
| MSP2A | 0.65 | 0.28 | 0.14 | 0.56 (0.01–0.71) | 0.28 (0.0–0.49) | |
| MSP2B | 0.54 | 0.23 | 0.38 | 0.58 (0.16–0.73) | 0 (0.0–0.42) | |
| IgE | AMA1 | 0.43 | 0.03 | 0.14 | 0.88 (0.78–0.93) | 0 (0.0–0.21) |
| MSP1-19 | 0.66 | 0.29 | 0 | 0.68 (0.43–0.81) | 0 (0.0–0.35) | |
| MSP2B | 0.50 | 0.36 | 0.28 | 0.49 (0.0–0.69) | 0.54 (0.0–0.71) | |
| MSP3B | 0.47 | 0.08 | 0.09 | 0.72 (0.44–0.84) | 0.01 (0.0–0.35) |
h 2, heritability estimates; r, Pearson's correlation coefficient; n, number of twin pairs; CI, confidence interval; MZ, monozygous twins; DZ, dizygous twins; those having a significant contribution by non-HLA genes are shown in bold. Analysis of IgE involved 56 MZ pairs.