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Objective:To analyze the clinical features and genotypes of mitochondrial complex Ⅰ deficiency due to NDUFAF5 gene mutations.Methods:Clinical data of 2 cases with mitochondrial complex Ⅰ deficiency due to NDUFAF5 gene mutations admitted in the Department of Pediatrics, Peking University First Hospital from February 2015 to July 2018 were retrospectively reviewed and followed up.Reported cases of mitochondrial complex Ⅰ deficiency due to NDUFAF5 gene mutations were searched in online databases, including the PubMed, Wanfang, Chinese Journal Full-Text Database and VIP database from January 1975 to February 2020 with " NDUFAF5" as the key word.Through literature review, clinical features and genotypes of mitochondrial complex Ⅰ deficiency due to NDUFAF5 gene mutations were summarized.Results:Case 1 showed mentor and mental regression after infection at the age of 1 year and 4 months.The condition of case 1 remained stable at the age of 5 year and 6 months at the last follow-up.Brain magnetic resonance imaging (MRI) showed multiple lesions in the white matter of the frontal and parieto-occipital lobes, basal ganglia, thalamus, cerebellum, brain stem and corpus callosum.Case 2 showed rapidly bilateral visual impairment at the age of 7 years and 4 months.The patient′s vision moderately recovered at the age of 8 years and 8 months.Brain MRI showed midbrain, periaqueductal gray, medulla oblongata and putamen lesions.Spinal MRI showed continuous lesions in the cervical cord 1-4.Genetic test showed NDUFAF5 gene c. 764C>T (p.Ala255Val) and c. 508C>T (p.Arg170Trp), homozygous c. 836T>G (p.Met279Arg) mutations in case 1 and case 2 respectively.Through online searching, 6 reports involving 14 cases were retrieved.The most common clinical phenotype was Leigh syndrome.Two cases had disease onset during the neonatal period, and their disease progressed rapidly and died within 1 year old.Eleven cases had onset during the infantile period, and 72.7% (8/11 cases) of them had a normal development.The common initial symptoms were mental or motor regression, feeding difficulty and dystonia.Seventy-two point seven percent (8/11 cases) had acute/subacute onset after infection, showing paroxysmal deterioration, and died in infancy or childhood.One patient developed dystonia in childhood and visual impairment in adulthood.Conclusions:The onset age ranged from neonatal period to childhood in patients with NDUFAF5 gene mutations, and their clinical phenotypes vary a lot.The main clinical phenotype is Leigh syndrome.Disease onset during the infantile period is frequent, and mostly presents paroxysmal deterioration after infection, while disease onset in childhood is rare.
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Objective To analyze the clinical and imaging features of 2 siblings with leukoencephalopathy due to NADH dehydrogenase (ubiquinone)flavoprotein 2 (NDUFV2) gene mutation,in order to better understand and diagnose it earlier.Methods Clinical and follow-up data of the proband and his brother were collected.Clinical features including symptoms,signs and cranial magnetic resonance imaging (MRI) were analyzed,and 2 patients were followed up for a long time.Sanger sequencing,targeted next generation sequencing,and whole exome sequencing were performed to identify potential genetic variations in the 2 patients and their parents.Results (1) Clinical characteristics and follow-up:ages of onset were 4 months and 1 year respectively.Both of the patients presented rapid motor regression hyperinyotonia,positive pathological character.During the follow-up the condition became stable,motor function and cognition improved gradually after cocktail therapy.(2) Brain MRI of the 2 patients showed prominent abnormalities in deep cerebral white matter,presenting T1 hypointense,T2 and fluid attenuated inversion recovery (FLAIR) hyperintense in the periventricular area.FLAIR images revealed that the abnormal white matter was partially rarefied and cavitated.Diffusion weighted images (DWI) showed high signals along the periphery of the involved areas.The follow-up MRI showed the cavitation still existed and even expanded,and DWI showed regional linear or spotty high signals around the original lesions.(3) Novel mutations in NDUFV2 gene,c.467T>A and c.404G>C,were identified in proband and his brother.The former inherited from his father,while the latter inherited from his mother,which was the new mutation not reported in the international.Conclusions The clinical features of the brothers presented subacute leukoencephalopathy with relatively stable or improved outcome.This was distinctive from the phenotypic features reported in 12 cases with hypertrophic cardiomyopathy or Leigh syndrome.The finding expanded the phenotypic spectrum of NDUFV2 mutations.Pathogenic gene of these patients which is the basis of genetic counseling for this family was determined.
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Objective To study the effects of repeated hypoxic exposures (HEs) on glycolysis, mitochondrial oxi-dative phosphorylation and energy charge in mouse brain. Methods Adult BALB/c mice were repeatedly exposed to hypoxia for 5 times and the standard tolerant time and body temperature were recorded. The activities of PFK, PK and mitochondrial complex Ⅰ in the brain were assayed. Phosphoadenosines and energy charge were measured. Results Repeated HEs prolonged the hypoxic tolerance and reduced the body temperature. The activities of PFK and PK experienced regular changes, with an increase in 1st and 3rd HEs and a decline to control levels in 5th HE. The complex Ⅰ activity continued to decrease during HEs. The energy charge was stable. Conclusion HEs lead to a regular change of glycolysis, a continued inhibition of mitochondrial oxidative phosphorylation, and a main-tained energy charge in the brains of mouse.