Facile and Scalable Synthesis Method for High-Quality Few-Layer Graphene through Solution-Based Exfoliation of Graphite.

Here we describe a facile and scalable method for preparing defect-free graphene sheets exfoliated from graphite using the positively charged polyelectrolyte precursor poly(p-phenylenevinylene) (PPV-pre) as a stabilizer in an aqueous solution. The graphene exfoliated by PPV-pre was apparently stabilized in the solution as a form of graphene/PPV-pre (denoted to GPPV-pre), which remains in a homogeneous dispersion over a year. The thickness values of 300 selected 76% GPPV-pre flakes ranged from 1 to 10 nm, corresponding to between one and a few layers of graphene in the lateral dimensions of 1 to 2 µm. Furthermore, this approach was expected to yield a marked decrease in the density of defects in the electronic conjugation of graphene compared to that of graphene oxide (GO) obtained by Hummers' method. The positively charged GPPV-pre was employed to fabricate a poly(ethylene terephthalate) (PET) electrode layer-by-layer with negatively charged GO, yielding (GPPV-pre/GO)n film electrode. The PPV-pre and GO in the (GPPV-pre/GO)n films were simultaneously converted using hydroiodic acid vapor to fully conjugated PPV and reduced graphene oxide (RGO), respectively. The electrical conductivity of (GPPV/RGO)23 multilayer films was 483 S/cm, about three times greater than that of the (PPV/RGO)23 multilayer films (166 S/cm) comprising RGO (prepared by Hummers method). Furthermore, the superior electrical properties of GPPV were made evident, when comparing the capacitive performances of two supercapacitor systems; (polyaniline PANi/RGO)30/(GPPV/RGO)23/PET (volumetric capacitance = 216 F/cm3; energy density = 19 mWh/cm3; maximum power density = 498 W/cm3) and (PANi/RGO)30/(PPV/RGO)23/PET (152 F/cm3; 9 mWh/cm3; 80 W/cm3).

[Psychomotor retardation and intermitent convulsions for 8 months in an infant].

This study reports a boy with psychomotor retardation and epilepsy due to maternal phenylketonuria (PKU). The boy was admitted at the age of 20 months because of psychomotor retardation and epilepsy. He had seizures from the age of 1 year. His development quotient was 43. He presented with microcephaly, normal skin and hair color. Brain MRI scan showed mild cerebral white matter demyelination, broadening bilateral lateral ventricle and foramen magnum stricture. Chromosome karyotype, urine organic acids, blood amino acids and acylcarnitines were normal. His mother had mental retardation from her childhood. She presented with learning difficulties and yellow hair. Her premarriage health examinations were normal. She married a healthy man at age of 26 years. When she visited us at 28 years old, PKU was found by markedly elevated blood phenylalanine (916.54 µmol/L vs normal range 20-120 µmol/L). On her phenylalanine hydroxylase (PAH) gene, a homozygous mutations c.611A>G (p.Y204C) was identified, which confirmed the diagnosis of PAH-deficient PKU. Her child carries a heterozygous mutation c.611A>G with normal blood phenylalanine. Her husband had no any mutation on PAH. It is concluded that family investigation is very important for the etiological diagnosis of the children with mental retardation and epilepsy. Carefully clinical and metabolic survey should be performed for the parents with mental problems to identify parental diseases-associated child brain damage, such as maternal PKU.

[Acute brainstem encephalitis and myelitis in a girl with isolated methylmalonic aciduria due to MUT gene defect].

Methylmalonyl CoA mutase deficiency due to MUT gene defect has been known as the main cause of isolated methylmalonic acidemia in Mainland China. This study reported a patient with isolated methylmalonic aciduria (MUT type) characterized as acute brainstem encephalitis and myelitis. The previously healthy girl presented with fever, lethargy and progressive weakness in her extremities at the age of 3 years and 2 months. Three day later, she had respiratory distress and consciousness. Cranial MRI revealed bilateral symmetrical lesion of pallidum, brain stem and spinal cord, indicating acute brainstem encephalitis and myelitis. Her blood propionylcarnitine (6.83 µmol/L vs normal range 1.0 to 5.0 µmol/L) and urinary methylmalonic acid (133.22 mmol/mol creatinine vs normal range 0.2 to 3.6 mmol/mol creatinine) increased significantly. Plasma total homocysteine was normal. On her MUT gene, a reported mutation (c.1630_1631GG>TA) and a novel mutation (c.1663C>T, p.A555T) were identified, which confirmed the diagnosis of methylmalonic aciduria (MUT type). After cobalamin injection, protein-restricted diet with the supplements of special formula and L-carnitine, progressive improvement has been observed. The clinical manifestation of patients with methylmalonic aciduria is complex. Metabolic study and gene analysis are keys for the diagnosis and treatment of the disorder.

[A Chinese boy with methylmalonic aciduria cblB type and a novel mutation in the MMAB gene].

cblB defect is a rare type of methylmalonic aciduria. In this study, a Chinese boy was diagnosed with methylmalonic aciduria cblB type and a novel mutation in the MMAB gene. The clinical presentations, blood acylcarnitines profiles, urine organic acids and genetic features of the patient were reported. The boy presented with fever, feeding difficulty and lethargy at the age of 2 months. Seven days later, he had coma, cold limb, thrombocytopenia, metabolic acidosis and liver damage. His blood propionylcarnitine and urinary methylmalonic acid levels increased significantly, but the plasma total homocysteine level was in the normal range, which supported the diagnosis of isolated methylmalonic aciduria. Gene analysis was performed by direct sequencing. No mutation in the MUT gene was found. However, a reported mutation c.577G>A (p.E193K) and a novel mutation c.562G>A (p.V188M) in the MMAB gene were identified, which confirmed the diagnosis of methylmalonic aciduria cblB type. Progressive clinical and biochemical improvement has been observed after hydroxylcobalamin injection, protein-restricted diet with the supplements of special formula and L-carnitine. He is currently 3 years and 11 months old and has a normal development condition. The phenotypes of the patients with cblB defect are nonspecific. Metabolic analysis and MMAB gene analysis are keys for the diagnosis of the disorder.

Dopamine-melanin nanofilms for biomimetic structural coloration.

This article describes the formation of dopamine-melanin thin films (50-200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8-11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.

[Clinical and ATP7A gene analysis of three infants with Menkes disease and prenatal diagnosis for a fetus at risk].

Menkes disease is a rare X-linked recessive disorder characterized by multi-systemic disorder of copper deficiency caused by ATP7A gene mutation. In this study, the clinical and laboratory features of three patients with Menkes disease were analyzed. Prenatal diagnosis had been performed for a fetus of a family. Three patients were admitted at the age of 8-9 months due to severe epilepsies and marked delayed psychomotor development. Significantly light complexion, pudgy cheeks and sparse fuzzy wooly hair were observed. On their cranial MR imaging, cortical atrophy, leukoencephalopathy, basal ganglia damage and tormesity of the intracranial vessels were found. Their plasma ceruloplasmin decreased to 70.2, 73.5 and 81 mg/L, significantly lower than normal range (210-530 mg/L). c.3914A>G (p. D1305G) was detected on ATP7A gene of case 1 and 2. A novel mutation, c.3265G>T (p.G1089X) was found in case 3. Both of them were firstly found in Chinese patients of Menkes disease. The mother of case 1 was tested at 20 weeks of pregnancy. Karyotype and ATP7A gene studies of the amniocytes were performed for the prenatal diagnosis of her fetus. Normal male karyotypes without c.3914A>G mutation on ATP7A gene was showed. Postnatal genetic analysis and normal development confirmed the prenatal diagnosis.

[Methylenetetrahydrofolate reductase deficiency-induced schizophrenia in a school-age boy].

Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. It is known that MTHFR deficiency may result in hyperhomocysteinemia, but MTHFR deficiency-induced schizophrenia has been rarely reported. Here we present the clinical course, biochemical and genetic characteristics of schizophrenia resulted from MTHFR deficiency in a school-age boy. He was 13 years old. He was admitted with a two-year history of fear, auditory hallucination, learning difficulty, sleeping problems, irascibility, drowsing and giggling. At admission, he had significantly elevated plasma and urine levels of total homocysteine, significantly decreased levels of folate in serum and cerebrospinal fluid, and a normal blood concentration of methionine. Further DNA sequencing analysis showed 665C>T homozygous mutations in the MTHFR gene. The patient was diagnosed with MTHFR deficiency-associated schizophrenia and treatment with calcium folinate, vitamin B12, vitamin B6, and betaine was initiated. After the treatment for 1 week, his plasma and urine levels of homocysteine were decreased to a normal range and the clinical symptoms were significantly improved. After 3 months of treatment, the patient returned to school. He is now living with normal school life. In summary, children with late-onset MTHFR deficiency and secondary cerebral folate deficiency may lead to schizophrenia. This rare condition can be early diagnosed through analyses of blood and urine total homocysteine, amino acids in blood and folate in blood and cerebral fluid and successfully treated with folinic acid, vitamin B6, vitamin B12 and betaine.

Prenatal diagnosis of citrullinemia type 1: a Chinese family with a novel mutation of the ASS1 gene.

BACKGROUND: Argininosuccinate synthetase deficiency (citrullinemia type 1) is a rare autosomal recessive disorder of the urea cycle characterized by elevated concentrations of citrulline, ammonia, and orotic acid, manifesting with acute hyperammonemic crises, usually early in life, with concurrent neurologic deterioration. Only a few cases of citrullinemia type 1 have been documented from mainland China. Prenatal diagnosis has not been performed. METHODS: A Chinese family affected by citrullinemia type 1 was studied. The proband, a girl, was the second child born to a non-consanguineous couple. Her elder brother died at 19months due to coma and liver dysfunction of unknown cause. The proband was admitted because of severe mental retardation and lethargy at the age of 15months. Initial laboratory results revealed hyperammonaemia, hypercitrullinemia (928.771µmol/L, normal 5.0-25.0µmol/L) and orotic aciduria, supporting the diagnosis of citrullinemia type 1. Subsequently, the mother presented at 15weeks of pregnancy seeking for genetic counseling and prenatal diagnosis. ASS1 gene in the blood leukocytes of the family members and amniocytes was performed by direct sequencing. RESULTS: On the ASS1 gene of the proband, a novel mutation, T1009C (C337R), and a previously reported mutation G847A (E283K) were identified. Each parent carries one of two mutations. G847A and T1009C mutations were detected in amniocytes, as same as the proband of the family. The result revealed that the fetus was affected by argininosuccinate synthetase deficiency. The parents chose to have a termination of the pregnancy. CONCLUSIONS: Prenatal diagnosis for citrullinemia type 1 was performed in a Chinese family using gene analysis. T1009C (C337R), a novel mutation of ASS1, was identified.

Two compound frame-shift mutations in succinate dehydrogenase gene of a Chinese boy with encephalopathy.

OBJECTIVE: To investigate respiratory chain complex II deficiency resulted from mutation in succinate dehydrogenase gene (SDH) encoding complex II subunits in China. METHODS: An 11-year-old boy was admitted to our hospital. He had a history of progressive psychomotor regression and weakness since the age of 4years. His cranial magnetic resonance imaging revealed focal, bilaterally symmetrical lesions in the basal ganglia and thalamus, indicating mitochondrial encephalopathy. The activities of mitochondrial respiratory chain enzymes I-V in peripheral leukocytes were determined via spectrophotometry. Mitochondrial DNA and the succinate dehydrogenase A (SDHA) gene were analyzed by direct sequencing. RESULTS: Complex II activity in the leukocytes had decreased to 33.07nmol/min/mg mitochondrial protein (normal control 71.8±12.9); the activities of complexes I, III, IV and V were normal. The entire sequence of the mitochondrial DNA was normal. The SDHA gene showed two heterozygous frame-shift mutations: c.G117G/del in exon 2 and c.T220T/insT in exon 3, which resulted in stop codons at residues 56 and 81, respectively. CONCLUSIONS: We have described the first Chinese case of mitochondrial respiratory chain complex II deficiency, which was diagnosed using enzyme assays and gene analysis. Two novel, compound, frame-shift mutations, c.G117G/del in exon 2 and c.T220T/insT in exon 3 of the SDHA gene, were found in our patient.

[Advances in clinical and molecular genetics studies on argininemia].

Argininemia is a rare, autosomal recessive, metabolic disorder caused by an hereditary deficiency of hepatocytes arginase due to ARG1 gene defect. Arginase is the final enzyme in the urea cycle, catalyzing the hydrolysis of arginine to ornithine and urea. Research advances in the clinical manifestations, diagnosis, treatment, prenatal diagnosis and genetics of argininemia were reviewed in this paper. The clinical manifestations of patients with argininemia are complicated and nonspecific so that clinical diagnosis is usually difficult and delayed. Progressive spastic tetraplegia, seizures and cerebella atrophy are common clinical features of the disease. Blood amino acids analysis, arginase assay and ARG1 gene analysis are important to the diagnosis of argininemia. Early diagnosis and a protein-restricted diet with citrulline and benzoate supplements can contribute a lot to improve patient prognosis. With the application of liquid chromatography-tandem mass spectrometry in selective screening and newborn screening for inborn errors of metabolism, an ever-increasing number of patients with argininemia are detected at the asymptomatic or early stages.

Genetic and biochemical findings in Chinese children with Leigh syndrome.

This study investigated the genetic and enzymological features of Leigh syndrome due to respiratory chain complex deficiency in Chinese patients. The clinical features of 75 patients were recorded. Mitochondrial respiratory chain enzyme activities were determined via spectrophotometry. Mitochondrial gene sequence analysis was performed in 23 patients. Five core pedigrees were investigated via restriction fragment length polymorphism and gene sequencing. Psychomotor retardation (55%), motor regression (20%), weakness (29%), and epilepsy (25%) were the most frequent manifestations. Sixty-four patients (85.3%) had isolated respiratory complex deficiencies: complex I was seen in 28 patients (37.3%); complex II, seven (9.3%); complex III, six (8%); complex IV, ten (13.3%); and complex V, 13 patients (17.3%). Eleven patients (14.7%) had combined complex deficiencies. Mitochondrial DNA mutations were detected in 10 patients. Eight point mutations were found in mitochondrial structural genes: m.4833A>G in ND2, m.10191T>C in ND3, m.12338T>C and m.13513G>A in ND5, m.14502T>C and m.14487T>C in ND6, m.8108A>G in COXII, and m.8993T>G in ATPase6. Three mutations were found in tRNA genes: m.4395A>G in tRNA-Gln, m.10454T>C in tRNA-Arg, and m.5587T>C in tRNA-Ala. One patient and their mother both had the m.12338T>C and m.8993T>C mutations. In conclusion, mitochondrial respiratory chain complex I deficiency and structural gene mutations frequently occur in Chinese Leigh syndrome patients.

Five novel mutations in ARG1 gene in Chinese patients of argininemia.

BACKGROUND: Argininemia is an autosomal recessive genetic disorder caused by hepatocyte arginase deficiency. It could be detected by blood amino acids analysis (high arginine) and confirmed by molecular diagnosis. The clinical manifestations in patients are similar to cerebral palsy so the diagnosis is usually much delayed. Reports of argininemia from mainland China are few, and genetic analyses have not been reported. PATIENTS AND METHODS: Five Chinese patients with argininemia were investigated. They had progressive spastic tetraplegia, poor physical growth from 1 month to 4 years. When argininemia was found at the ages of 4 to 12 years, four of patients had mental retardation, and three had seizures. RESULTS: Elevated blood arginine and significantly decreased erythrocyte arginase activity in five patients confirmed the diagnosis of arginase deficiency. Liver dysfunction was found in four patients, two of whom had mildly elevated blood ammonia levels. Cranial magnetic resonance imaging showed progressive cerebral atrophy in three patients. Six mutations in the ARG1 gene were identified, of which only one (c.703 G>A, p.G235R) in exon 7 has been reported before; c.34 G>T (p.G12X) in exon 1, c.67delG (p.G23fsX31) in exon 2, c.539G>C (p.R180 T) in exon 5, c.374C>T (p.A125 V) in exon 4, and c.646-649del CTCA (p.T215fsX219) in exon 6 were novel mutations. CONCLUSIONS: Argininemia is one of the few treatable causes of pediatric spastic paraparesis. Early metabolic investigation is very important to reach a diagnosis and better outcome. Five Chinese patients with late-diagnosed argininemia were reported. The mutation spectrum of ARG1 gene should be different from other populations.

[A boy with Fabry disease with the onset at the age of four].

Fabry disease is an X-linked recessive lysosomal storage disorder caused by a deficiency of α-galactosidase A (GLA). Intracellular accumulation of globotriaosylceramide, the glycolipid substrate of this enzyme, leads to severe painful neuropathy with progressive renal, cardiovascular, and cerebrovascular dysfunction. Patients of severe cases die young. It has been proved that enzyme replacement therapy is a useful method to treat patients with Fabry disease. But the clinical diagnosis of the patients may often be difficult because of the lack of specific symptoms. In this study, a Chinese boy was diagnosed as Fabry disease at the age of 11 years with episodic pain for 7 years. The boy described the onset, at the age of 4 years, of episodic burning pain in the toes. Generalized aching and pain in the feet became progressive in the past two years and his hands were also affected. Divers analgesics were tried without effects. When he was admitted at the age of 11 years, none of complications was found in his heart, brain, kidneys, skin and eyes by routine laboratory examinations. Significantly decreased GLA activity of peripheral leucocytes [1.0 nmol/(h×mg protein) vs. normal control 24.5 to 86.1 nmol/(h×mg protein)] supported the diagnosis of Fabry disease. A splicing mutation IVS6+2 T>C was identified on his GLA gene. But it was not found in his mother and younger sister. The incidence of Fabry disease is not clear in Mainland China. The patients usually have insidious onset with complex and non-specific clinical manifestations. Stroke, uremia, cardiomyopathy and multiple organ dysfunctions are common at the late stage. Early diagnosis is the key point to reduce the mortality and handicap. GLA enzyme activity is important to the diagnosis of Fabry disease. The mutation analysis of GLA gene is helpful for genetic counseling.

Heterogeneity of six children and their mothers with mitochondrial DNA 3243 A>G mutation.

To study the clinical, biochemical, and genetic heterogeneity of six Chinese patients and their mothers with the 3243 A>G mutation, six patients (ranging from 5 to 11 years) were hospitalized. All the mothers were healthy. Mitochondrial respiratory chain enzyme activities were determined by spectrophotometry. Mitochondrial gene was analyzed in all patients. Six core pedigrees were investigated. Two patients had mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome and one had Leigh syndrome. The common initial symptoms were headache, vomiting, blurred vision, and epilepsy. m.3243A>G mutation was detected in all patients and their mothers. The mutation loads ranged from 43.6% to 58% and those of their mothers ranged from 14.1% to 28.6%. Varied respiratory chain deficiencies were observed in all patients and two mothers. m.3243A>G mutation can result in a wide spectrum of respiratory chain complex deficiencies. Mitochondrial DNA mutation detected in blood may be likely to transmit to offspring, and the mutation load may increase.

Mitochondrial respiratory chain enzyme assay and DNA analysis in peripheral blood leukocytes for the etiological study of Chinese children with Leigh syndrome due to complex I deficiency.

Mitochondrial respiratory chain complex I enzyme deficiency is the most commonly seen mitochondrial respiratory chain disorder. Although screening and diagnostic methods are available overseas, clinically feasible diagnostic methods have not yet been established in China. In this study, four Chinese boys with Leigh syndrome due to complex I deficiency were diagnosed by mitochondrial respiratory chain enzyme assay and DNA analysis using peripheral blood leukocytes. Four patients were admitted at the age of 5-14 years because of unexplained progressive neuromuscular symptoms, including motor developmental delay or regression, weakness, and seizures. Their cranial magnetic resonance imaging revealed typical finding as Leigh syndrome. Peripheral leukocyte mitochondrial respiratory chain complex I activities were found decreased to 9.6-33.1 nmol/min/mg mitochondrial protein(control 44.0 ± 5.4 nmol/min/mg). The ratios of complex I to citrate synthase activity were also decreased (8.9-19.8% in patients vs. control 48 ± 11%). Three mtDNA mutations were identified from three out of four patients, supporting the diagnosis of complex I deficiency. Point mutations m.10191T>C in mitochondrial ND3 gene, m.13513G>A in ND5 gene and m.14,453G>A in ND6 gene were detected in three patients.

[Clinical, biochemical and genetic analysis of the mitochondrial disorders presenting with cardiac damage].

OBJECTIVE: Mitochondrial disease is a group of energy metabolic disorders, characterized by involvement of multisystem with high energy requirements. Encephalomyopathies are common clinical findings of the mitochondrial diseases. However, mitochondrial cardiac damage is not rare. In this study, the clinical, biological, and genetic analyses were performed in three patients with mitochondrial cardiac damage, in order to understand the characteristics of mitochondrial diseases. METHOD: Three girls presented with arrhythmia and cardiac enlargement from the age of 3, 4 and 8 years respectively. They were admitted into the Peking University First Hospital. Infection, autoimmune diseases, aminoacidopathies, organic acidurias, mitochondrial-fatty acid oxidation defects, and lysosomal storage disease were excluded by routine laboratory examinations and metabolic analysis for blood amino acids, acylcarnitines, urinary organic acids, and lysosome activity assay. Peripheral leukocytes mitochondrial respiratory chain enzyme I to V activities were measured by spectrophotometry. The entire sequence of the mitochondrial DNA was analyzed. RESULT: In two patients (case 1 and case 3), hypertrophic cardiomyopathy and grade I to grade II of cardiac function were found. One patient (case 2) was diagnosed with arrhythmia and grade I of cardiac function. Increased creatine phosphokinase and creatine kinase isoenzyme MB were observed. Mitochondrial respiratory chain complex deficiencies were indentified in the three patients. Patient 1 had combined deficiencies of complex III and V. The activity of complex I+III was 18.7 nmol/(min·mg mitochondrial protein) (control 84.4 ± 28.5). The activity of complex V was 20.4 nmol/(min·mg mitochondrial protein) (control 103.7 ± 29.2). In her mitochondrial gene, A14693G on tRNA(Glu) and T16519C on D-loop were found. Patient 2 had an isolated complex I deficiency. The activity was 22.0 nmol/(min·mg mitochondrial protein) (control 44.0 ± 5.4). A16183C, T16189C and G15043A mutations on D-loop were found. Patient 3 had a combined deficiency of complex IV and V. The activity of complex IV was 21.0 nmol/(min·mg mitochondrial protein) (control 54.1 ± 12.3). The activity of complex V was 23.2 nmol/(min·mg mitochondrial protein) (control 103.7 ± 29.2). C253T and C16187T mutations on D-loop were detected. Haplotype analysis showed that three patients belong to H2a2a. Improvement was observed after the treatment with L-carnitine, coenzyme Q10, vitamin C and E. At present, the patients are 7, 5 and 8 years old. Although excise intolerance still persists, they had a good general condition with normal school life. CONCLUSION: The mitochondrial diseases with cardiac damage show cardiomyopathy, arrhythmia and exercise intolerance. Many kinds of mitochondrial respiratory chain deficiency were observed. A14693G in mitochondrial tRNA(Glu) gene is probably one of the causes in China.

[Abnormal findings during newborn period of 160 patients with early-onset methylmalonic aciduria].

OBJECTIVE: Methylmalonic aciduria is the most common disorder of organic acidurias in the mainland of China. It is also the one of treatable metabolic disorders. The clinical spectrum of the patients varies from severe neonatal-onset forms with neonatal brain injury and high mortality to milder forms with adult-onset. The clinical manifestations of neonates with methylmalonic aciduria are non-specific. Early diagnosis and adequate treatment contribute a lot to improving the prognosis of the patients. In this study, the abnormal clinical and laboratory findings in neonatal period of 160 Chinese patients with early-onset methylmalonic aciduria were investigated. METHOD: From 1996 to 2011, a total of 398 patients with methylmalonic aciduria were diagnosed in our hospital; 286 (71.9%) patients had early-onset before 1 year of age. Among 286 patients, 160 (55.9%) presented symptoms in neonatal period. Their urine organic acids were analyzed by gas chromatography-mass spectrometry. Blood amino acids and acylcarnitine profiles were determined by liquid chromatography tandem mass spectrometry. Serum and urine total homocysteine were measured using a fluorescence polarization immunoassay. In some patients, gene analysis was performed. Based on the disease types and general condition, individual dietary and medical interventions were started soon after diagnosis. RESULT: Out of the 160 patients, 131 (81.9%) had combined methylmalonic aciduria and homocysteinemia. Isolated methylmalonic aciduria was found in 29 cases (18.1%). The common presentations in neonatal period were feeding difficulty, seizures, lethargy and dyspnea. Megaloblastic anemia, liver dysfunction, hyperammonemia and metabolic acidosis were the frequent findings in the routine laboratory test. The most common initial clinical diagnosis was suspected hypoxic-ischemic encephalopathy. Even in 36 cases with abnormal family history, only 3 patients were admitted with suspected inborn errors of metabolism. Five cases (3.1%) were diagnosed by postmortem metabolic examination; 7 cases (4.4%) were detected by newborn screening. In 148 cases (92.5%), the diagnosis was much delayed to the age of one month to 8 years and 5 months (mean 13 months). Methylmalonic aciduria combined with homocysteinemia (MMACHC) gene analyses were performed in 31 cases with combined methylmalonic aciduria. CblC defect was confirmed. The patients with isolated methylmalonic aciduria were treated with protein-restricted diet, cobalamin and L-carnitine. The patients of methylmalonic aciduria combined with homocysteinemia were treated with cobalamin, L-carnitine, calcium folinate, betaine and common diet. Seven patients died without treatment. Clinical improvement was observed in 153 patients. Only 2 patients detected by newborn screening had normal mental and physical development. Mild to severe psychomotor retardation was observed in 151 cases. CONCLUSION: High mortality and disability rates were observed in the patients with early-onset methylmalonic aciduria. Combined methylmalonic aciduria and homocysteinemia is the common type of methylmalonic aciduria. The clinical manifestation in neonatal period of the patients with early-onset methylmalonic aciduria is complex. Feeding difficulty, seizures, lethargy and dyspnea are the common symptoms in neonatal period of the patients. Megaloblastic anemia, liver dysfunction, hyperammonemia and metabolic acidosis were the frequent laboratory findings.

[Mitochondrial respiratory chain complex I deficiency due to 10191T>C mutation in ND3 gene].

This study reviews a case of mitochondrial respiratory chain complex I deficiency due to the 10191T>C mutation in mitochondrial ND3 gene. The previously healthy boy progressively presented with blepharoptosis, weakness, epilepsy and motor regression at age 6 years. Elevated blood lactate and pyruvate were observed. Brain magnetic resonance imaging showed symmetrical lesions in the basal ganglia. Leigh syndrome was thus confirmed. The protein from the mitochondria and genomic DNA of the boy and his parents was collected from peripheral blood leucocytes for the activity test for mitochondrial complex I to V and genetic analysis. The results showed the activity of complex I (33.1 nmol /min in 1 milligram mitochondrial protein) was lower than normal reference value (44.0±5.4 nmol /min in 1 milligram mitochondrial protein). The ratio of complex I to citrate synthase (19.8%) was also lower than normal reference value (48%±11%). The activities of complexes II to V were normal. 10191T>C mutation in ND3 gene of mitochondria was identified in the boy. 10191T>C mutation and complex I deficiency were not detected in his parents. At present, he is 16 years old, and of normal intelligence with spastic paralysis in both lower extremities after treatment. It is concluded that a Chinese boy with isolated complex I deficiency due to 10191T>C mutation in ND3 gene was firstly diagnosed by peripheral leukocytes mitochondrial respiratory chain enzyme assay and gene analysis. This study can provide clinical data for the nosogenesis of Leigh syndrome.

[Intrahepatic cholestasis due to mitochondrial respiratory chain complex I deficiency in a Chinese boy].

Mitochondrial respiratory chain deficiency is a common cause of mitochondrial disease in children. This study aimed to review the clinical, enzymatic and genetic characteristics of a Chinese boy with progressive intrahepatic cholestasis due to mitochondrial respiratory chain complex I deficiency. The boy developed diarrhea from the age of 13 months, followed by progressive body weight loss, jaundice and weakness. His urine organic acids, blood amino acids and acylcarnitines profiles were normal. Mitochondrial respiratory chain complexes I to V activities in peripheral leukocytes were measured using spectrophotometric assay. Complex I activity was reduced. 5821G>A mutation was indentified by gene sequencing on tRNA-cys of mitochondrial gene in the patient and his mother. Vitamin supplements, liver protection, antibiotics and plasma infusion were not effective in the patient. Unfortunately, the boy died at the age of 17 months. Mitochondrial respiratory chain complex I deficiency is the most common mitochondrial respiratory chain disorder. This was the first case of intrahepatic cholestasis due to complex I deficiency confirmed by mitochondrial respiratory chain enzyme activity assay and gene analysis in China. It was concluded that mitochondrial hepatopathy is one of major causes of metabolic hepatopathy. Biochemical assay, mitochondrial respiratory chain complex activities assay and genetic analysis are crucial for the etiological diagnosis of metabolic hepatopathy.