1 => The disorder is placed on the map based on its association with a gene, but the underlying defect is not known
2 => The disorder has been placed on the map by linkage; no mutation has been found
3 => The molecular basis for the disorder is known; a mutation has been found in the gene
4 => A contiguous gene deletion or duplication syndrome, multiple genes are deleted or duplicated causing the phenotype
| Gene Symbol | Chromosomal Location | Gene MIM number | Mapping Method | Phenotype | Phenotype MIM number | Phenotype Mapping Key |
| GAD1 | 2q31.1 | 605363 | REa, H, A, Psh, Fd, LD | ?Cerebral palsy, spastic quadriplegic, 1, 603513 (3) | 603513 | 3 |