| A hereditary disorder associated with impaired DNA double-strand break repair mechanisms with characteristics of microcephaly, unusual facial features, growth and developmental delay, skin anomalies, and pancytopenia, which is associated with combined immunodeficiency. Caused by mutations in the LIG4 gene (13q22-q34). The resulting defect of DNA ligase IV, a component of the classical non-homologous end-joining (NHEJ) pathway, affects the major mechanism of DNA double-strand break repair. Transmission is autosomal recessive. |
