<unk>  is caused by a mutation in the<unk> 1 gene, located at human chromosome 8q21. The disease is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome (chromosome 8 is an autosome), and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder. Two adult siblings, both heterozygous for two particular<unk> 1 nonsense mutations displayed cellular sensitivity to radiation, chromosome instability and fertility defects, but not the developmental defects that are typically found in other<unk>  patients. These individuals appear to be primarily defective in homologous recombination, a process that accurately repairs double-strand breaks, both in somatic cells and during meiosis.
Nijmegen breakage syndrome
Peutz–Jeghers syndrome
Mismatch repair cancer syndrome
Warsaw breakage syndrome
MUTYH-associated polyposis
Letterer–Siwe disease
Sturge–Weber syndrome
Van Den Bosch syndrome