Abstract: 【Abstract】 A male patient， who was aged 3 months and 12 days, presented with well-circumscribed erythema and scales on the scrotum, perineum, buttocks and perianal region at 1 month after birth. The lesions gradually involved the perioral and axillary regions, flexor aspect of the elbow, popliteal fossa and neck. Shortness of breath, crying, dysphoria and vomiting occurred without fever and cough 3 days before hospitalization. Laboratory examinations at admission showed metabolic acidosis, hyperlactacidemia, hyperammonemia and organic aciduria. Second-generation sequencing and Sanger sequencing of the holocarboxylase synthetase gene revealed a known mutation c.1522C>T in exon 9 and a novel mutation c.1796_1814del in exon 11. According to a guideline from the American College of Medical Genetics and Genomics, this novel mutation was ranked as a pathogenic mutation. The patient was diagnosed as multiple carboxylase deficiency. His clinical symptoms were improved after oral biotin treatment, no neurological symptoms or signs were observed.

Key words: Multiple carboxylase deficiency, Skin manifestations, Biotin, Holocarboxylase synthetase gene, Mutation