Table 1.
The three-residue grip model of susceptibility to immune mediated diabetes
| allele | β9 | β37 | Non-Asp β57 | score | T1D |
| DRB1*0101 | Hydrophobic W | Polar S | No | 1 | No |
| DRB1*0301 | Polar E | Polar N | No | 2 | Yes |
| DRB1*0401 | Polar E | Polar Y | No | 2 | Yes |
| DRB1*0402 | Polar E | Polar Y | No | 2 | Yes |
| DRB1*0403 | Polar E | Polar Y | No | 2 | No |
| DRB1*0404 | Polar E | Polar Y | No | 2 | Yes |
| DRB1*0405 | Polar E | Polar Y | Yes S | 3 | Yes |
| DRB1*0406 | Polar E | Polar S | No | 2 | No |
| DRB1*0407 | Polar E | Polar Y | No | 2 | Yes |
| DRB1*0408 | Polar E | Polar E | No | 2 | Yes |
| DRB1*0409 | Polar E | Polar Y | Yes S | 3 | Yes |
| DRB1*07 | Hydrophobic W | Hydrophobic F | Yes V | 1 | No |
| DRB1*0801 | Polar E | Polar Y | Yes S | 3 | Yes |
| DRB1*0901 | Charged K | Polar N | Yes V | 3 | Yes |
| DRB1*1001 | Polar E | Polar Y | No | 2 | No |
| DRB1*11 | Polar E | Polar Y/N/S/D | No | 2 | Yes |
| DRB1*11 | Polar E | Hydrophobic, F | No | 1 | No |
| DRB1*12 | Polar E | Hydrophobic L/F | Yes V | 2 | No |
| DRB1*1301 | Polar E | Polar N | No | 2 | Yes |
| DRB1*1303 | Polar E | Polar Y | Yes S | 3 | Yes |
| DRB1*1401 | Polar E | Hydrophobic F | Yes A | 2 | No |
| DRB1*1402 | Polar E | Polar N | No | 2 | No |
| DRB1*15 | Hydrophobic W | Polar S | No | 1 | No |
| DRB1*16 | Hydrophobic W | Polar S | No | 1 | No |
| DRB3*0101 | Polar E | Hydrophobic F | Yes V | 2 | No |
| DRB3*0200 | Polar E | Polar Y | No | 2 | Yes |
| DRB5*0202 | Polar Q | Polar D/N | No | 2 | Yes |
| DQB1*05 | Polar Y | Polar Y | Yes V | 3 | Yes |
| DQB1*0201 | Polar Y | Hydrophobic I | Yes A | 2 | Yes |
| DQB1*0301 | Polar Y | Polar Y | No | 2 | Yes |
| DQB1*0302 | Polar Y | Polar Y | Yes A | 3 | Yes |
| DQB1*0303 | Polar Y | Polar Y | No | 2 | Yes |
| DQB1*0601 | Hydrophobic L | Polar D | No | 1 | No |
| DQB1*0602 | Hydrophobic F | Polar Y | No | 1 | No |
| DQB1*0603 | Polar Y | Polar Y | No | 2 | No |
| DQB1*0604 | Polar Y | Polar Y | Yes V | 3 | Yes |
Polymorphic residues within pocket P9 of class II MHC alleles are scored according to whether they are polar/charged (+1), hydrophobic (0) or whether the conserved β57 aspartic acid is replaced (+1). A replacement at β57 Asp leaves α76 Arg free to coordinate an acidic peptide anchor in P9, or when the pocket is hydrophobic move out of the pocket. Two polar residues in the pocket or a polar residue and β57 aspartic acid mutation distinguishes between alleles that predispose to diabetes and those that do not with few exceptions. Diabetes association in column 6 is culled from the published literature. DR11 is listed both as a susceptibility allele and as a resistant (neutral) allele. Typing was to two significant figures; this obscures the nature of residue at β37.