[Clinical features and follow-up study on 55 patients with adolescence-onset methylmalonic acidemia].

Objective: To investigate the clinical features and outcomes of adolescence-onset methylmalonic acidemia (MMA) and explore preventive strategies. Methods: This was a retrospective case analysis of the phenotypes, genotypes and prognoses of adolescence-onset MMA patients. There were 55 patients diagnosed in Peking University First Hospital from January 2002 to June 2023, the data of symptoms, signs, laboratory results, gene variations, and outcomes was collected. The follow-ups were done through WeChat, telephone, or clinic visits every 3 to 6 months. Results: Among the 55 patients, 31 were males and 24 were females. The age of onset was 12 years old (range 10-18 years old). They visited clinics at Tanner stages 2 to 5 with typical secondary sexual characteristics. Nine cases (16%) were trigged by infection and 5 cases (9%) were triggered by insidious exercises. The period from onset to diagnosis was between 2 months and 6 years. Forty-five cases (82%) had neuropsychiatric symptoms as the main symptoms, followed by cardiovascular symptoms in 12 cases (22%), kidney damage in 7 cases (13%), and eye disease in 12 cases (22%). Fifty-four cases (98%) had the biochemical characteristics of methylmalonic acidemia combined with homocysteinemia, and 1 case (2%) had the isolated methylmalonic acidemia. Genetic diagnosis was obtained in 54 cases, with 20 variants identified in MMACHC gene and 2 in MMUT gene. In 53 children with MMACHC gene mutation,1 case had dual gene variants of PRDX1 and MMACHC, with 105 alleles. The top 5 frequent variants in MMACHC were c.482G>A in 39 alleles (37%), c.609G>A in 17 alleles (16%), c.658_660delAAG in 11 alleles (10%), c.80A>G in 10 alleles (10%), c.567dupT and c.394C>T both are 4 alleles (4%). All patients recovered using cobalamin, L-carnitine, betaine, and symptomatic therapy, and 54 patients (98%) returned to school or work. Conclusions: Patients with adolescence-onset MMA may triggered by fatigue or infection. The diagnosis is often delayed due to non-specific symptoms. Metabolic and genetic tests are crucial for a definite diagnosis. Treatment with cobalamin, L-carnitine, and betaine can effectively reverse the prognosis of MMA in adolescence-onset patients.

[Analysis of 9 patients with adolescence-onset methylenetetrahydrofolate reductase deficiency].

Objective: To explore the diagnosis and treatment of adolescence-onset methylenetetrahydrofolate reductase (MTHFR) deficiency. Methods: This was a retrospective case study. Nine patients with adolescence-onset MTHFR deficiency were diagnosed at Peking University First Hospital from January 2016 to December 2022, and followed up for more than 1 year. Their general information, clinical manifestations, laboratory tests, cranial images, MTHFR gene variants, diagnosis, treatment, and outcome were analyzed retrospectively. Results: The 9 patients came from 8 families. They had symptoms at age of 8.0 years to 17.0 years and diagnosed at 9.0 years to 17.5 years. Eight were male and 1 was female. Two patients were brothers, the elder brother developed abnormal gait at 17.0 years; and the younger brother was then diagnosed at 15.0 years of age and treated at the asymptomatic stage, who was 18.0 years old with normal condition during this study. The main manifestations of the 8 symptomatic patients included progressive dyskinesia and spastic paralysis of the lower limbs, with or without intellectual decline, cognitive impairment and behavioral abnormalities. Totally, 15 variants of MTHFR gene were identified in the 9 patients, including 8 novel variants. Five patients had brain image abnormalities. Increased plasma total homocysteine level (65-221 µmol/L) was found in all patients, and decreased to 20-70 µmol/L after treatment with betaine and calcium folinate. Besides, the 8 symptomatic patients had their behavior and cognitive problems significantly improved, with a legacy of lower limb motor disorders. Conclusions: Late-onset MTHFR deficiency can occur in adolescence. The diagnosis is usually delayed because of non-specific clinical symptoms. The test of blood total homocysteine could be used as a selective screening test. Eight novel varients of MTHFR gene were identified. Timely treatment can improve clinical condition significantly, and pre-symptomatic treatment may prevent brain damage.

[Phenotypes and genotypes of 78 patients with propionic acidemia].

Objective: Propionic acidemia is a rare inherited metabolic disorder caused by propionyl CoA carboxylase (PCC) deficiency. This study aims to analyze the clinical characteristics and gene variations of Chinese patients with propionic acidemia, and to explore the correlation between clinical phenotypes and genotypes. Methods: Single-center, retrospective and observational study. Seventy-eight patients of propionic acidemia (46 males and 32 females) from 20 provinces and autonomous regions were admitted from January 2007 to April 2022. Their age of initial diagnosis ranged from 7 days to 15 years. The clinical manifestations, biochemical and metabolic abnormalities, genetic variations, diagnosis, treatment and outcome were studied. Chi-Square test or Mann-Whitney U test were used for statistical analysis. Results: Among 78 cases, 6 (7.7%) were identified by newborn screening; 72 (92.3%) were clinically diagnosed after onset, and the age of onset was 2 hours after birth to 15 years old; 32 cases had early-onset disease and 40 cases had late-onset disease. The initial manifestations included lethargy, hypotonia, vomiting, feeding difficulties, developmental delay, epilepsy, and coma. Among the 74 cases who accepted gene analysis, 35 (47.3%) had PCCA variants and 39 (52.7%) had PCCB variants. A total of 39 PCCA variants and 32 PCCB variants were detected, among which c.2002G>A and c.229C>T in PCCA and c.838dupC and c.1087T>C in PCCB were the most common variants in this cohort. The variants c.1228C>T and c.1283C>T in PCCB may be related to early-onset type. The variants c.838dupC, c.1127G>T and c.1316A>G in PCCB, and c.2002G>A in PCCA may be related to late-onset disease. Six patients detected by newborn screening and treated at asymptomatic stage developed normal. The clinically diagnosed 72 cases had varied complications. 10 (12.8%) cases of them died. 62 patients improved after metabolic therapy by L-carnitine and diet. Six patients received liver transplantation because of recurrent metabolic crisis. Their clinical symptoms were markedly improved. Conclusion: The clinical manifestations of propionic acidemia are complex and lack of specificity. Newborn screening and high-risk screening are keys for early treatment and better outcome. The correlation between the genotype and phenotype of propionic acidemia is unclear, but certain variants may be associated with early-onset or late-onset propionic acidemia.

[Clinical characteristics and CBS gene analysis of 13 cases with classic homocystinuria].

Objective: To analyze the clinical features and CBS gene variants of 13 patients with classic homocystinuria, and the strategies of individual treatment and prevention were explored. Methods: The general information, clinical manifestations, laboratory tests, cranial images, CBS gene variants, diagnosis and therapeutic strategies of 13 patients with classic homocystinuria admitted to the Department of Pediatrics of Children's Hospital Affiliated to Zhengzhou University and Peking University First Hospital from November 2013 to June 2021 were analyzed retrospectively. Results: There were 13 patients diagnosed at the age of 10 days to 14 years, 6 were male and 7 were female. There were 3 patients detected by newborn screening and received treatment at the asymptomatic stage. There were 10 patients clinically diagnosed at the age of 5 to 14 years. Their symptoms appeared at age of 1 to 6 years. The major clinical manifestations were marfanoid features, lens dislocation and (or) myopia, developmental delay, osteoporosis, and cardiovascular diseases. Brain magnetic resonance imaging showed asymmetric infarcts in 4 patients and hypomyelination in 1 case. Increased blood methionine, plasma total homocysteine and urinary total homocysteine with normal urinary methylmalonic acid were found in 13 patients. The biochemical features were consistent with classic homocystinuria. Totally 18 variants were identified in CBS gene of 13 patients, 10 variants were novel and 8 were reported. only 1 patient was partially responsive to vitamin B6 treatment, while 12 cases were non-responsive. They were mainly treated with low methionine diet and betaine supplement. Three vitamin B6 non-responsive cases received liver transplantation at age of 3, 8 and 8 years, respectively. Their blood methionine and total homocysteine returned to normal within a week after liver transplantation. One patient died. Prenatal diagnosis was performed for a fetus when the mother was pregnant again. Two pathogenic CBS gene variants were identified from the amniocytes as same as the proband. Conclusions: The clinical manifestations of classic homocystinuria are complex and variable. Blood amino acid analysis, serum or urine total homocysteine assay and gene analysis are critical for its diagnosis. There were 10 novel CBS gene varients were identified expanding the CBS gene varient spectrum. Liver transplantation is an effective treatment. Prenatal diagnosis is important to prevent classic homocysteinuria.

[Molecular epidemiological investigation on Theileria in yellow cattle from Xiangxi Autonomous Prefecture of Hunan Province].

OBJECTIVE: To investigate the prevalence and genetic variation of Theileria in yellow cattle in Xiangxi Autonomous Prefecture of Hunan Province. METHODS: A total of 184 blood specimens were collected from Fenghuang, Huanyuan and Baojing counties of Xiangxi Autonomous Prefecture during the period from August 2018 through August 2019, and were detect using PCR assay with the specific 18S ribosomal rRNA (18S rRNA) gene targeting Theileria. The gene sequences of positive specimens were aligned with the sequences recorded in GenBank, and a phylogenetic tree was created with Plasmodium ovale 18S rRNA as an outgroup. RESULTS: A total of 143 blood samples were positive for Theileria, with a mean detection rate of 77.7%. Theileria was prevalent in the blood samples from yellow cattle in all three counties, with detection rates of 85.0% in Fenghuang County, 88.3% in Huayuan County and 61.0% in Baojing County, respectively. There was no significant difference in the detection rate of Theileria between Xiangxi yellow cattle and normal yellow cattle (77.2% vs. 79.5%; χ2 = 0.08, P > 0.05), while the detection of Theileria was significantly lower in the housed yellow cattle than in free-range cattle (68.9% vs. 89.7%; χ2 = 22.36, P < 0.01). A total of 18 PCR positive samples were randomly selected for sequencing and analysis, and all samples showed more than 99.0% homology with T. luwenshuni isolates. Phylogenetic analysis showed that the 18 positive samples were clustered into the same branch with T. luwenshuni, but were far away from other isolates. CONCLUSIONS: The prevalence of Theileria is high in yellow cattle from Xiangxi Autonomous Prefecture of Hunan Province, and T. luwenshuni may be the dominant parasite species.

[Clinical and genetic studies on 76 patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria].

Objective: To analyze the clinical features, genetic characteristics, treatment and follow-up results of patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria, and to discuss the optimal strategies for assessing and treating such patients. Methods: From January 1998 to December 2020, 76 patients with hydrocephalus due to methylmalonic acidemia combined with homocysteinuria in the Department of Pediatrics in 11 hospitals including Peking University First Hospital were diagnosed by biochemical, genetic analysis and brain imaging examination. The patients were divided into operation-group and non-operation-group according to whether they underwent ventriculoperitoneal shunt. The clinical features, laboratory examinations, genotype, and follow-up data were retrospectively analyzed. Data were compared between the two groups using rank sum test, and categorical data were compared using χ2 test. Results: Among the 76 patients (51 male, 25 female), 5 were detected by newborn screening, while 71 were diagnosed after clinical onset, 68 cases (96%) had early-onset, 3 cases (4%) had late-onset. The most common clinical manifestations of 74 cases with complete data were psychomotor retardation in 74 cases (100%), visual impairment in 74 cases (100%), epilepsy in 44 cases (59%), anemia in 31 cases (42%), hypotonia or hypertonia in 21 cases (28%), feeding difficulties in 19 cases (26%) and disturbance of consciousness in 17 cases (23%). Genetic analysis was performed in 76 cases, all of whom had MMACHC gene variations, including 30 homozygous variations of MMACHC c.609G>A. The most common variations were c.609G>A (94, 62.7%), followed by c.658_660del (18, 12.0%), c.567dupT (9, 6.0%) and c.217C>T (8, 5.3%). Therapy including cobalamin intramuscular injection, L-carnitine and betaine were initiated immediately after diagnosis. A ventriculoperitoneal shunt operation was performed in 41 cases (operation group), and 31 patients improved after metabolic intervention (non-operation group). There was no significant difference in the age of onset, the age of diagnosis, the blood total homocysteine, methionine, and urinary methylmalonic acid concentration between the two groups (all P>0.05). The symptoms of psychomotor development, epilepsy, and visual impairments improved gradually after a long-term follow-up in the operation group. Conclusions: Hydrocephalus is a severe complication of methylmalonic acidemia combined with homocysteinuria. The most common clinical manifestations are psychomotor retardation, visual impairment, and epilepsy. It usually occurs in early-onset patients. Early diagnosis and etiological treatment are very important. Hydrocephalus may improve after metabolic intervention in some patients. For patients with severe ventricular dilatation, prompt surgical intervention can improve the prognosis.

[Clinical efficacy of two-staged Fowler-Stephens laparoscopic orchidopexy in the treatment of children with high cryptorchidism].

Objective: To Evaluate the clinic effect of two-staged laparoscopic Fowler-Stephens orchiopexy in the treatment of high cryptorchidism, and compare it with laparoscopic orchiopexy treatment without disconnecting spermatic vessels. Methods: A retrospective analysis was conducted on 20 cases of children with high cryptorchidism who were treated with two-staged Fowler-Stephens orchiopexy from January 2015 to April 2019 (F-S group). All the children in this group had unilateral cryptorchidism, age 6 to 18 months. The average age was 13.5 months. Seven cases were on the left side, and 13 cases were on the right side. There were 20 control children in the same age group who were treated with testicular fixation without disconnecting spermatic vessels, age 6 to 18 months. The average age was 12.5 months. Six cases were on the left side, and 14 cases were on the right side. Testicular ultrasonography and sex hormone examination were conducted before operation. F-S group met the indications for Fowler-Stephens surgical. In the first stage, the testicular vessels were doubly clipped at a site away from the testis in laparoscopic, and the second stage was scheduled about 6 months after the first stage. The children in the control group were treated with laparoscopic orchiopexy without disconnect spermatic vessels. The two groups were followed up to 6 months after the operation, and the testicular volume and sex hormone indexes of the two groups were measured. The testicular volume and sex hormones before and after the operation of the F-S group and the control group were respectively subjected to a self-control study, and a hormone comparison study was carried out between the two groups of children. Results: Both the F-S group and the control group successfully fixed the testes in the scrotum without tension during the operation. In both groups, 20 cases of testicular positions were reexamined 6 months after the operation without retraction. All the patients had a viable testis in scrotum after operation. Two of F-S group had an atrophic testis in the scrotum, and the others had a good vascularization detected on echo color doppler ultrasound. The average testicular volume of F-S group was (0.34±0.16) ml before operation and the postoperative one was (0.38±0.13) ml, P=0.089, P>0.05. In control group, the preoperative average testicular volume was (0.40±0.14) ml, and postoperative one was (0.40±0.15) ml, P=0.933, P>0.05. The testicular volume of two group had no significant difference. Sex hormone reexamination: Testosterone (T), estradiol (E2) and luteinizing hormone (LH) did not change after operation. Prolactin (PRL) in F-S group was 13.44 µg/L before operation and 12.3 µg/L after operation, PRL in control group was from 15.45 µg/L to 10.34 µg/L, P=0.732, the change of prolactin (PRL) has no significant difference. The median preoperative follicle stimulating hormone (FSH) in the F-S group was 1.18 U/L preoperatively and 1.61 U/L postoperatively; the median FSH of the control group was 1.21 U/L preoperatively and 1.1 U/L postoperatively. Compared between the two groups, the postoperative increase in the FS group was higher than that before the operation, P=0.032, P<0.05, the difference was statistically significant. The median of progesterone (PROG) in the F-S group was 0.25 nmol/L before operation and 0.17 nmol/L after operation; the median PROG of the control group was 0.56 nmol/L before operation and 0.24 nmol/L after operation. It was lower after the operation than before the operation, P=0.034, P<0.05, the difference was statistically significant. Conclusions: (1) Laparoscopic Fowler-stephens staging operation is an effective method for the treatment of patients with high cryptorchidism, and it is worthy of further promotion. (2) Disruption of spermatic cord vessels does have an impact on hormones changes. The choice of this surgical procedure should be carefully and fully evaluated.

[The phenotypes and genotypes in 314 patients with isolated methylmalonic acidemia].

Objectives: To summarize the clinical and genetic characteristics of the patients with isolated methylmalonic acidemia and investigate the strategies for the diagnosis, treatment and prevention. Methods: Three hundred and fourteen patients (180 males, 134 females) with isolated methylmalonic acidemia were ascertained from 26 provinces or cities across the mainland of China during January 1998 to March 2020. Genetic analysis was performed by Sanger sequencing, gene panel sequencing, whole exome sequencing, multiplex ligation-dependent probe amplification or quantitative PCR. According to the age of onset, the patients were divided to early-onset group (≤12 months of age) and the late-onset group (>12 months of age). They were treated by cobalamin, L-carnitine and (or) special diet and symptomatic treatment. Statistical analysis was done using Chi-square test. Results: Fifty-eight of 314 (18.5%) patients were detected by Newborn screening using liquid chromatography tandem mass spectrometry. Five cases (1.6%) had a postmortem diagnosis. Two hundred and fifty-one patients (79.9%) were clinically diagnosed with an age of onset ranged from 3 hours after birth to 18 years. One hundred and fifty-nine patients (71.0%) belonged to early-onset groups, 65 patients (29.0%) belonged to the late-onset group. The most common symptoms were metabolic crises, psychomotor retardation, epilepsy, anemia and multiple organ damage. Metabolic acidosis and anemia were more common in early-onset patients than that in late-onset patients (20.8%(33/159) vs. 9.2% (6/65), 34.6% (55/159) vs. 16.9% (11/165), χ(2)=4.261, 6.930, P=0.039, 0.008). Genetic tests were performed for 236 patients (75.2%), 96.2%(227/236) had molecular confirmation. One hundred and twenty-seven variants were identified in seven genes (MMUT, MMAA, MMAB, MMADHC, SUCLG1, SUCLA2, and MCEE), of which 49 were novel. The mut type, caused by the deficiency of methylmalonyl-CoA mutase, was the most common (n=211, 93%) cause of this condition. c.729_730insTT, c.1106G>A and c.914T>C were the three most frequent mutations in MMUT gene. The frequency of c.914T>C in early-onset patients was significantly higher than that in late-onset patients (8.3% (18/216) vs. 1.6% (1/64), χ(2)=3.859, P=0.037). Metabolic crisis was more frequent in mut type than the other types (72.6% (114/157) vs. 3/13, χ(2)=13.729, P=0.001),developmental delay and hypotonia were less frequent in mut type (38.2% (60/157) vs. 9/13, 25.5% (40/157) vs. 8/13, χ(2)=4.789, 7.705, P=0.030, 0.006). Of the 58 patients identified by newborn screening, 44 patients (75.9%) who were treated from asymptomatic phase developed normally whereas 14 patients (24.1%) who received treatment after developing symptoms exhibited varying degrees of psychomotor retardation. Conclusions: The characteristics of phenotypes and genotypes among Chinese patients with isolated methylmalonic acidemia were analyzed. Expanded the mutation spectrum of the associated genes. Because of the complex clinical manifestations and severe early onset of isolated methylmalonic acidemia, Newborn screening is crucial for early diagnosis and improvement of prognosis. MMUT gene is recommended for carrier screening as an effort to move the test earlier as a part of the primary prevention of birth defects.

[Heterogeneous phenotypes, genotypes, treatment and prevention of 1 003 patients with methylmalonic acidemia in the mainland of China].

Objective: To analyz the current situation of the diagnosis, treatment and prevention of methylmalonic acidemia, the phenotypes, biochemical features and genotypes of the patients in the mainland of China, were investigated. Methods: Tottally 1 003 patients of methylmalonic acidemia from 26 provinces and municipalities of the mainland of China were enrolled. The clinical data, biochemical features and gene mutations were studied. Blood aminoacids and acylcarnitines, urine organic acids, and plasma total homocysteine were determined for the biochemical diagnosis. Gene analyses were performed for the genetic study of 661 patients. The patients were treated with individual intervention and long-term follow up. Prenatal diagnoses were carried out for 165 fetuses of the families. Results: Among 1 003 patients (580 boys and 423 girls), 296 cases (29.5%) had isolated methylmalonic acidemia; 707 cases (70.5%) had combined homocysteinemia; 59 patients (5.9%) were detected by newborn screening; 944 patients (94.1%) had the onset at the ages from several minutes after birth to 25 years and diagnosed at 3 days to 25 years of age. The main clinical presentations were psychomotor retardation and metabolic crisis. Multi-organ damage, including hematological abnormalities, pulmonary hypertension, kidney damage, were found. MMACHC, MUT, MMAA, MMAB, HCFC1, SUCLG1, SUCLA2 mutations were found in 631 patients (96.6%) out of 661 patients who accepted gene analysis. MMACHC mutations were detected in 460 patients (94.7%) out of 486 cases of methylmalonic acidemia combined with homocysteinemia. MUT mutations were found in 158 (90.3%) out of 169 cases of isolated methylmalonic acidemia. The development of 59 patients detected by newborn screening were normal; 918 cases (97.2%) were diagnosed after onset accepted the treatment. Forty-five of them completely recovered with normal development. Twenty-six patients (2.7%) died; 873 (92.5%) patients had mild to severe psychomotor retardation. Methylmalonic acidemia were found in 35 out of 165 fetuses by metabolites assay of amniotic fluid and amniocytes gene analysis. Conclusion: Combined methylmalonic acidemia and homocysteinemia is the common type of methylmalonic acidemia in the mainland of China. CblC defect due to MMACHC mutations is the most common type of methylmalonic acidemia combined with homocysteinemia. MUT gene mutations are frequent in the patients with isolated methylmalonic acidemia. Newborn screening is key for the early diagnosis and the better outcome. Combined diagnosis of biochemical assays and gene analysis are reliable for the prenatal diagnosis of methylmalonic acidemia.

[Clinical diagnosis and treatment of three cases with hyperornithinemia-hyperammonemia-homocitrullinuria syndrome].

Objective: To study the clinical characteristics, methods of diagnosis and treatment of hyperornithinemia-hyperammonemia- homocitrullinuria (HHH) syndrome. Method: From July 2011 to August 2016, 3 Chinese patients with HHH syndrome were enrolled in this study. The clinical course, biochemical features, brain MRI findings, and gene mutations were analyzed. Result: The three patients' age at onset of symptoms was 3 months to 7 years, and the age of diagonosis was 3 years and 10 months to 9 years and 10 months. All of them presented with intolerance to protein-rich foods from the infant period, development retardation and abnormal posture. Case 1 and 2 had moderate mental retardation. Serum ammonia 25-276 µmol/L (reference range<60 µmol/L), alanine aminotransferase (ALT) 20-139 IU/L (reference range 9-50 IU/L), ornithine 29.12-99.44 µmol/L(reference range 15-100 µmol/L), urinary orotic acid 1.49-29.75 mmol/mol Cr (reference range 0-7 mmol/mol Cr), uracil 6.09-103.97 mmol/mol Cr (reference range 0-1.5 mmol/mol Cr). The cranial MRI revealed lesions in the basal ganglia, abnormal white matter signal, progressive demyelination and cerebral atrophy. On their SLC25A15 gene, a novel homozygous missense mutation c. 416A>G (p.E139G) was identified in case 1, a known pathogenic homozygous nonsense mutation c. 535C>T was found in case 2 and 3. Liver transplantation had been performed when case 1 was 6 years old. Significant improvements were observed in dietary habit, mental and motor functions, and biochemical parameters. After the dietary intervention with the supplements of arginine, L-carnitine, case 2 was improved, spastic paraplegia of case 3 had no mitigation. Liver transplant was recommended. Conclusion: HHH syndrome has an aversion to protein-rich food, and the patients have recurrent vomiting and progressive neurological dysfunction. Clinical diagnosis of HHH syndrome is difficult and patients may present with incomplete biochemical phenotype. The genetic analysis is key for the diagnosis. Depending on their condition, individuals with HHH syndrome can be treated with a low-protein diet, drugs and liver transplantation.

[Two cases with generalized intracranial calcification due to hereditary folate malabsorption and literature review].

Objective: This study aimed to investigate the clinical, biochemical and genetic features of two Chinese children with hereditary folate malabsorption. Method: Clinical features, laboratory examinations, treatment and SLC46A1 gene of two cases were studied. Reports on hereditary folate malabsorption utill September of 2016 were searched and the clinical and genetic characteristics of reported cases were summarized. Result: The two patients presented with megaloblastic anemia from their infant period and seizures, psychomotor retardation and regression. In case1, mean corpuscular volume (MCV) was 100 fl. Serum folate was 9.96 nmol/L. Folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were 0 and 0.01 separately. In case 2, MCV was 93.9 fl. Serum folate was 4.49 nmol/L. The concentration of folate and 5-methylenetetrahydrofolate in cerebrospinal fluid were both zero. On their brain CT, progressive bilateral symmetrical calcification was observed. On their SLC46A1 gene, four mutations were identified. Case 1 had one novel mutation, c. 1238T>C (L413P) and c. 194-195insG (p.Cys66LeufsX99). From Case 2, two reported mutations, c. 1A>T (M1L) and c. 194-195insG (p.Cys66LeufsX99) were identified. The administration of folinic acid (60 to 120 mg per day) was initiated after diagnosis. Clinical improvement and normalized hematologic markers were observed after treatment. Totally 37 cases were reported in reviewed English literature, including 30 cases with mutations on SLC46A1 gene (only one Chinese patient). All the cases had the onset in infancy. The ratio of boys to girls was 1 to 1.5. Main manifestations were characterized by megaloblastic anemia (77%), failure to thrive (50%), diarrhea (27%), psychomotor retardation (63.6%), epilepsy (27%), and infection of respiratory system (45.5%). The concentration of folate in both serum and cerebrospinal fluid was decreased (72.7% and 63.6% respectively). Hypoimmunoglobulinemia accounted for 27.3%. Most of mutations in HFM were distributed between p. 65 and p. 68 (c.194-c.204), mainly due to insertion- or deletion-related frame shifts or generation of stop codons. Oral and parenteral folinic acid treatment was effective. Conclusion: Hereditary folate malabsorption often presented with megaloblastic anemia, abnormalities of digestive and nervous system, and hypoimmunoglobulinemia with recurrent infections. Low level of serum and CSF folate and screening SLC46A1 gene are keys to the etiologic study of the patients. Early supplement with folinic acid is beneficial to the prognosis.

Effect of Selenium Supplementation on Recurrent Hyperthyroidism Caused by Graves' Disease: A Prospective Pilot Study.

The effect of selenium supplementation on recurrent hyperthyroidism caused by Graves' disease is unclear. Our study aimed to assess the efficacy of selenium supplementation therapy on recurrent Graves' disease. Forty-one patients with recurrent Graves' disease were enrolled in this study. All patients received the routine treatment using methimazole (MMI), while patients allocated to the selenium group received additional selenium therapy for 6 months. The influence of selenium supplementation on the concentrations of thyroid stimulating hormone (TSH), anti-TSH-receptor antibodies (TRAb), free thyroxine (FT4), and free triiodothyronine (FT3) were assessed. The remission rate was also compared between 2 groups. There was no obvious difference in the demographic data and the levels of serum FT4, FT3, TSH, and TRAb between the 2 groups at baseline. Both FT4 and FT3 decreased more at 2 months in the selenium group than the controls, while the TSH level increased more in patients receiving selenium supplementation (p<0.05). The TRAb level was significantly lower in patients receiving selenium supplementation (2.4 IU/l vs. 5.6 IU/l, p=0.04). The percentages of patients with normal TRAb level at 6 months was also significantly higher in the selenium group (19.0 vs. 0%, p=0.016). Kaplan-Meier survival curve showed patients receiving selenium supplementation had a significantly higher rate of remission than controls (Log-rank test p=0.008). In conclusion, selenium supplementation can enhance the effect of antithyroid drugs in patients with recurrent Graves' disease. Randomized trials with large number of participants are needed to validate the finding above.

[Clinical and laboratory studies on four Chinese patients with succinate-CoA ligase deficiency noticed by mild methylmalonic aciduria].

OBJECTIVE: To study the clinical and genetic features of the patients with secondary methylmalonic aciduria due to succinate-CoA ligase deficiency. METHOD: From February 2011 to April 2014, 4 Chinese patients with succinate-CoA ligase deficiency and mild methylmalonic aciduria were enrolled in this study. The clinical course, biochemical features, brain MRI findings, and mutations were analyzed. RESULT: Four patients presented with severe psychomotor retardation, hypotonia, seizures, feeding problems and failure to thrive from the age of one day to 6 months. Three of them had intractable epilepsies. One had hearing defect. Mild methylmalonic aciduria was detected by elevated urine methylmalonic acid and blood propionylcarnitine at the age of 6 months to 2 years and 8 months. Five mutations, c. 550G>A, c. 751C>T, c. 809A>C, c. 961C>G and c. 826-2A>G in SUCLG1 of three patients were identified. On SUCLA2, one novel mutation, c. 970C>T, was found in one patient. After treatment, the disease in all four patients was improved. CONCLUSION: Four Chinese patients with succinyl-CoA ligase deficiency caused by SUCLG1 and SUCLA2 mutations were noticed by mild methylmalonic aciduria and diagnosed using high-throughput genomic sequencing. Succinate-CoA ligase deficiency is a rare cause of methylmalonic aciduria. Biochemical and gene studies are necessary for the differential diagnoses.

Sevoflurane induces neurotoxicity in young mice through FAS/FASL signaling.

Sevoflurane, the most widely used anesthetic in clinical practice, has been shown to induce apoptosis, inhibit neurogenesis, and cause learning and memory impairment in young mice. However, the underlying mechanism is still unknown. In this study, wild-type and the FAS- or FAS ligand (FASL)-knockout mice (age 7 days) were exposed to sevoflurane or pure oxygen. Western blotting was used to examine the expression of FAS protein. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) and bromodeoxyuridine (BrdU) staining were employed to quantify the apoptotic cells and newborn cells in the hippocampus and Morris water maze (MWM) in order to evaluate learning and memory status. Sevoflurane significantly increased the expression of FAS protein in wild-type mice. Compared to FAS- and FASL-knockout mice treated with sevoflurane, sevoflurane-treated wild-type mice exhibited more TUNEL-positive hippocampal cells and less BrdU-positive hippocampal cells. The MWM showed that compared with FAS- and FASL-knockout mice treated with sevoflurane, sevoflurane treatment of wild-type mice significantly prolonged the escape latency and reduced platform crossing times. These data suggest that sevoflurane induces neurotoxicity in young mice through FAS-FASL signaling.

A study of 133 Chinese children with mitochondrial respiratory chain complex I deficiency.

To investigate the clinical, enzymological and mitochondrial gene profiles of complex I deficiency in Chinese, clinical and laboratory data of the patients (79 boys, 54 girls) were retrospectively assessed. Activities of mitochondrial respiratory chain complexes in peripheral leucocytes were spectrophotometrically measured. The entire mitochondrial DNA (mtDNA) sequence was analyzed in 62 patients. Restriction fragment length polymorphism and gene sequencing analyses were performed in 15 families. Ninety-one patients had isolated complex I deficiency; 42 had combined deficiencies of complex I and other complexes. The main clinical presentations were neuromuscular disorders (107 patients) and non-neurological dysfunction (hepatopathy, renal damage and cardiomyopathy; 26 patients). In 32 of 62 patients who underwent mtDNA sequencing, 24 mutations were identified in 15 mitochondrial genes. The 12338T>C, 4833A>G and 14502T>C mutations were found in 12.9%, 11.3% and 4.8% patients, respectively. Seven patients had multiple mutations. Three novel mutations were identified. Chinese patients with complex I deficiency presented heterogeneous phenotypes and genotypes. Twenty-four mutations were identified in 15 mitochondrial genes in 51.6% patients. mtDNA mutations were more common in isolated complex I deficiency than in combined complex deficiencies. The 12338T>C, 4833A>G and 14502T>C mutations were common.