Objective　To explore the clinical and genetic characteristics of peroxisome biogenic disorders (PBD) caused by peroxin 1 (PEX1) complex heterozygous mutation. Method　The clinical data of PBD in a child were retrospectively analyzed and the related literature was reviewed. Results　A 4-years- and 6-months-old boy had mental retardation and no other obvious abnormalities. Gene detection found that there were two unreported heterozygous mutations in PBD related PEX1 gene in children, c.539A> c (p.lys180thr) and c.2704_2708delTTTAT (p.phe902fs), which were consistent with the autosomal recessive genetic pattern. The child was therefore diagnosed with PBD1B. Conclusions　The clinical phenotype of patients with PBD was diverse, and its severity was related to the mutation type of PEX1 gene. Genetic testing could confirm the diagnosis.