| Disease | Symptoms | Genetic defect |
|---|---|---|
| Xeroderma pigmentosum | Freckle-like spots on skin, sensitivity to sunlight, predisposition to skin cancer | Defects in nucleotide-excision repair |
| Cockayne syndrome | Dwarfism, sensitivity to sunlight, premature aging, deafness, intellectual disability | Defects in nucleotide-excision repair |
| Trichothiodystrophy | Brittle hair, skin abnormalities, short stature, immature sexual development, characteristic facial features | Defects in nucleotide-excision repair |
| Hereditary nonpolyposis colon cancer | Predisposition to colon cancer | Defects in mismatch repair |
| Fanconi anemia | Increased skin pigmentation, abnormalities of skeleton, heart, and kidneys, predisposition to leukemia | Possibly defects in the repair of inter-strand cross-links |
| Li–Fraumeni syndrome | Predisposition to cancer in many different tissues | Defects in DNA damage response |
| Werner syndrome | Premature aging, predisposition to cancer | Defect in homologous recombination |