Monarch Disease Ontology id MONDO_0011686 (DNA ligase IV deficiency) can be described as follows. LIG4 syndrome is a hereditary disorder associated with impaired DNA double-strand break repair mechanisms and characterized by microcephaly, unusual facial features, growth and developmental delay, skin anomalies, and pancytopenia, which is associated with combined immunodeficiency (CID). Also known as: LIG4 syndrome, ligase 4 syndrome.