A Patient With Mutations In DNA Ligase â…£: Clinical And Genetic Analysis

Objective: To investigate the clinical, immunological and geneticcharacteristics of a patient with mutation in DNA ligase IV, providingsuggestions for diagnosis and differential diagnosis.Methods: This study enrolled a2-year-old girl who presented withchronic diarrhea, microcephaly，growth delay, autoimmune cytopenia, andrecurrent infections. Sequencing of the LIG4gene, analysis of TCR-Vβdiversity and T lymphocyte proliferation were performed.Results: Sequencing of the patient’s LIG4gene revealed compoundheterozygote mutations (c.26C>T，T9I；c.833G>T，A278L), which hadbeen reported previously in patients with LIG4deficiency, the parents werecarriers for these mutations. Most of the TCR-Vβ subfamilies showedmonoclonal or oligoclonal peaks. T lymphocyte proliferation suggested thedysfunction of T cells proliferation.Conclusion: The present study identified the first patient with LIG4deficiency in China. Patient with radiosensitive combined immunodeficiency, micro-cephaly，growth delay and autoimmune disease should be suspected as LIG4deficiency, gene analysis should be perfor med for accurate diagnosis.