Abstract
Molybdenum cofactor deficiency (MoCD) is an autosomal recessive disease which leads to a combined deficiency of molybdenum cofactor dependent enzymes. There are four different genes in molybdenum cofactor biosynthesis, MOCS1, MOCS2, MOCS3, GEPH. The patients with MOCS2 homozygous mutation who onset in the neonatal period always have severe seizures, feeding difficulties, progressive neurological deterioration. The incidence of the disease is low, and certain types have never been reported in China. Here, we present a Chinese term infant with MOCS2 who presented seizure, intolerance to feed and hypotonia on the third day after birth. Treatment included intravenous nutrition, antibiotic, and anticonvulsant therapy. The seizure can't be controlled and her encephalopathy progressed. A homozygous mutation in exon 4 in MOSC2 gene was found and the mutation of the patient has not been reported before. In conclusion, the patients with MOCS2 who onset in neonatal period often shows uncontrolled seizure, feeding difficulties, hypotonia and early death. And the MRI of them shows severe encephalomalacia. There is no treatment for the disease by now, but early diagnosis and genetic detection can give the family genetic counseling.