Ligase IV syndrome (MIM #606593) is a disorder of DNA damage repair, with cellular hypersensitivity to ionizing radiation, caused by mutations in LIG4 (MIM #601837).
In particular, telomerase-deficient mice display hypersensitivity to ionizing radiation and delays in DSB repair that may reflect a defect in HR [37].
Such mutations result in radioresistant DNA synthesis (RDS) and hypersensitivity to ionizing radiation [ 10- 12].
Ataxia-telangiectasia (A-T) is a neurodegenerative, autosomal recessive disorder characterized by cerebellar ataxia, telangiectases (damaged small blood vessels) in the conjunctiva and skin, immunological deficiency, hypersensitivity to ionizing radiation and increased risk of cancer [ 1].
Cells lacking NHEJ exhibit variable proliferative defects, hypersensitivity to ionizing radiation and other clastogens and spontaneous chromosomal instability.
Already, hypersensitivity to ionizing radiation proved to be about four times higher in the group of patients than that observed in the groups of parents and controls.
Ataxia-telangiectasia is an autosomal-recessive disease that affects neuro-immunological functions, associated with increased susceptibility to malignancy, chromosomal instability and hypersensitivity to ionizing radiation.
Inactivation of Arabidopsis RAD50 or MRE11 leads to hypersensitivity to ionizing radiation or radiomimetics and reduced plant health and even sterility.
Ataxia-telangiectasia is an autosomal-recessive disease that affects neuro-immunologic functions, and is associated with increased susceptibility to malignancy, chromosomal instability and hypersensitivity to ionizing radiation [ 1, 2].
A-T patients manifest both cellular and clinical hypersensitivity to ionizing radiation, which results from disruption of the nuclear function of ATM in the recognition and response to DNA double-strand breaks (DSBs).
