The clinical and molecular characteristics of MOCS2 deficiency

Background: We explored the clinical and molecular characteristics of molybdenum cofactor deficiency due to MOCS2 muations. Methods: We summarize the genetic and clinical findings of previously reported patients with a MOCS2 mutation. We also present a new patient with novel neuroradiological findings associated with molybdenum cofactor deficiency due to a novel homozygous variant in the 5' untranslated region of the MOM gene. Results: The study population comprised 35 patients with a MOCS2 gene mutation. All reported children had delayed motor milestones. The major initial symptom was seizures in neonatal period. Facial dysmorphism was present in 61% of the patients. Only one patient had ectopia lentis. Agenesis of the corpus callosum and an associated interhemispheric cyst in our case are novel neuroradiological findings. Conclusions: The occurrence of neonatal seizures and feeding difficulties can be the first clinical signs of molybdenum cofactor deficiency. Although there is no effective therapy for this condition, early diagnosis and genetic analysis of these lethal disorders facilitate adequate genetic counseling. (C) 2019 Elsevier Inc. All rights reserved.