Methenyltetrahydrofolate synthease deficiency (MTHFS deficiency): Novel mutation and brain MRI findings: A case report and glance to other cases.

This is a case report of Methenyl Tetrahydrofolate synthetase deficiency (MTHFS deficiency) characterized by global developmental delay, cerebral hypomyelination, severe spastic tonicity in extremities, and microcephaly. Mutation in the MTHFS gene was reported in the Whole Exome Sequencing (WES) and confirmed with Sanger sequencing of parents. It is of great significance to report since it would be the first case of MTHFS mutation reported from Iran and the fourth throughout the world with novel mutation and brain imaging.