Abstract: Maple syrup urine disease, a rare hereditary disease, is due to the lack of branched-chain α-ketoaciddehydrogenase complex caused by abnormal gene expression. It occurs mostly in neonates or infants, and brain is the main organ involved, often manifested as mental or neurological symptoms. Severe cases can cause death of children. The clinical treatment is extremely difficult. Therefore, this disease seriously affects the outcomes of women reproductive health. This paper reports the outcomes of multiple pregnancy in a couple who both carried maple syrup urine disease gene, while reviews the literatures related to maple syrup urine disease. The discussion of the etiology, pathogenesis, clinical manifestations, diagnosis and treatment of the disease is very useful for us to broaden the vision, to be alert to this disease in future, and to do the early genetic testing and accurate genetic counseling for suspicious pregnant women in clinical work.

Key words: Maple syrup urine disease, Genes, Pregnancy outcome, Case report