Objective To investigate the clinical features of one pair of twin neonates with maple syrup urine disease(MSUD) in the Chinese Han population and pathogenic mutations in related genes,and to provide guidance for the early diagnosis and treatment of MSUD.Methods The clinical and imaging data of the twin neonates were collected.The peripheral blood samples were collected from the twin neonates and their parents to detect the genes related to MSUD(BCKDHA,BCKDHB,DBT,and DLD).The loci with gene mutations were i...