Mitochondrial complex II (CII, succinate dehydrogenase complex) deficiency is a rare cause of mitochondrial respiratory chain defects. CII functions in the TCA cycle and in the mitochondrial electron transport chain (ETC). Four structural subunits (SDHA, SDHB, SDHC and SDHD) and two known assembly factor genes (SDHAF1 and SDHAF2) are all nuclear-encoded. Mutations in SDHA, SDHD, and SDHAF1 have been found in patients. CII deficiency has a variable phenotype. Brain imaging is abnormal in majority of the patients and consists of leukoencephalopathy, Leigh syndrome or cerebellar atrophy.
Human diseases in ICD-11 classification [BR:br08403]
05 Endocrine, nutritional or metabolic diseases
Metabolic disorders
Inborn errors of metabolism
5C53 Inborn errors of energy metabolism
H02005 Mitochondrial complex II deficiency
Pathway-based classification of diseases [BR:br08402]
Carbohydrate metabolism
nt06031 Citrate cycle and pyruvate metabolism
H02005 Mitochondrial complex II deficiency
Cellular process
nt06529 Thermogenesis
H02005 Mitochondrial complex II deficiency
Alston CL, Davison JE, Meloni F, van der Westhuizen FH, He L, Hornig-Do HT, Peet AC, Gissen P, Goffrini P, Ferrero I, Wassmer E, McFarland R, Taylor RW
Title
Recessive germline SDHA and SDHB mutations causing leukodystrophy and isolated mitochondrial complex II deficiency.
