Abstract: A 12-year-old adolescent female with chronic kidney disease for more than 6 years. During this period, she was diagnosed with methylmalonic acidemia with hyperhomocysteinemia. The patient discontinued drug therapy six months ago.Renal biopsy indicated thrombotic microangiopathy (TMA) and genetic testing revealed compound heterozygous mutations in the MMACHC gene. The patients condition improved after receiving treatment with cobalamin, folic acid, betaine, levocarnitine, and fosinopril. There are few cases of MMA with renal injury. The aim is to expanded clinicians understanding of this disease.

Key words: methylmalonic acidemia, thrombotic microangiopathy, hyperhomocysteinemia, MMACHC gene