Abstract:A 15-day-old boy was admitted to the hospital due to repeated convulsions for 14 days. The main clinical manifestations were uncontrolled seizures, hypoergia, feeding difficulties, limb hypotonia, and bilateral hearing impairment. Clinical neurophysiology showed reduced brainstem auditory evoked potential on both sides and burst-suppression pattern on electroencephalogram. Measurement of very-long-chain fatty acids in serum showed that C26:0 was significantly increased. Genetic testing showed a pathogenic compound heterozygous mutation, c.101C>T(p.Ala34Val) and c.1448_1460del(p.Ala483Aspfs*37), in the HSD17B4 gene. This article reports a case of D-bifunctional protein deficiency caused by HSD17B4 gene mutation and summarizes the epidemiological and clinical features, diagnosis, and treatment of this disease, with a focus on the differential diagnosis of this disease from Ohtahara syndrome.