Rapidly Progressive Spastic Paraplegia Due to Hyperhomocysteinemia in Child with Gene Mutation and Mitochondrial Complex I Deficiency: A Rare Association.

MTHFR enzyme deficiency is an autosomal-recessive inborn error of folate metabolism. The deficiency cause defect in the remethylation of homocysteine to methionine leading to increased blood levels of homocysteine. Hyperhomocysteinemia in infants cause seizures, hypotonia, apnoea, microcephaly, progressing to coma and death if untreated whereas in childhood onset it causes developmental delay, seizures, psychiatric disturbances, spastic gait, and ataxia.