Abstract: Objective　To investigate the pathogenesis, clinical features, diagnosis and treatment of diseases caused by NBAS gene deficiency. Methods　Retrospectively analyze the clinical features, laboratory tests, genetic diagnosis, treatments and prognosis of two children with NBAS gene deficiency. Results　The proband is a 14 years and 6-months old boy, and his younger sister is 7-years and 11-months old. Both patients have progeroid face, optic atrophy, achromatopsia, short stature, liver dysfunction, hyperammonemia and hyperlactemia. Blood smear staining suggested abnormal Pelger-Hu?t granulocytes. The gene detection showed both the proband and his younger sister had c.5752A>C and c.1599+1G>C compound heterozygous mutations in NBAS gene inherited from their parents. c.5752A>C was already reported while c.1599+1G>C is a novel splicing mutation. Even without special treatment, the liver function of both patients has improved significantly with age. Conclusions　NBAS gene deficiency is a rare disease affecting optic nerves, liver and skeletal system. Patients mainly presented with progeroid face, optic atrophy, short stature and hepatic dysfunction. Genetic analysis was helpful for diagnosis. Currently, there is no specific treatment of this disease, and usually symptomatic treatment was applied.

Key words: 　NBAS gene;　progeroid face;　optic atrophy;　acute liver failure;　Pelger-Hu?t anomaly