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 |
| SYNJ1 | 21q22.11 | 604297 | A | Parkinson disease 20, early-onset, 615530 (3) | 615530 | 3 |
| SYNJ1 | 21q22.11 | 604297 | A | Epileptic encephalopathy, early infantile, 53, 617389 (3) | 617389 | 3 |