Apart from typical stigmata, patients with DNA ligase IV deficiency are characterized by progressive bone marrow failure and a predisposition to malignancy.
DNA Ligase 4-deficient patients suffer from a wide range of clinical manifestations since early in life, including: microcephaly, dysmorphic facial features, growth failure, developmental delay, mental retardation; hip dysplasia, and other skeletal malformations; as well as a severe combined immunodeficiency, radiosensitivity, and progressive bone marrow failure; or, they may present later in life with hematological neoplasias that respond catastrophically to chemo- and radiotherapy; or, they could be asymptomatic.
Such growth failure is therefore sufficient to consider a diagnosis of LIG4 deficiency and early recognition of such cases is important as bone marrow failure, immunodeficiency, and sometimes malignancy are long term sequelae of this disorder.