Inherited disorders caused by deficient DNA-repair enzymes

Ataxia-telangiectasia = DNA hypersensitivity to ionizing radiation = cerebellar atrophy, repeated infections, increased malignancy

Xeroderma pigmentosum = DNA = hypersensitive to UV radiation due to failed nucleotide excision repair. Increased for all types of skin cancer: basal, squamous, melanoma

Fanconi anemia = DNA can't repair damage from cross-linking agent exposure

Bloom Syndrome = generalized chromosoma instability. Increased risk of neoplasma.

Hereditary Nonpolyposis colorectal cancer (HNPCC), defect in DNA mismatch repair = leads to colon cancer