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 |
| SMAD1 | 4q31.21 | 601595 | Psh | NA | NA | NA |
| SMAD1 | 7p14.3 | 600287 | A, Fd | Charcot-Marie-Tooth disease, type 2D, 601472 (3) | 601472 | 3 |
| SMAD1 | 7p14.3 | 600287 | A, Fd | Neuropathy, distal hereditary motor, type VA, 600794 (3) | 600794 | 3 |