1.Hotelling T2 test and multivariated analysis of variance to analyzing nurse job burnout datum
Man LUO ; Shaopeng LIU ; Zhehui LI ; Yanfen ZHANG
Chinese Journal of Practical Nursing 2009;25(29):29-31
Objective To investigate the statistical.method for analyzing nurse job burnout Data. Methods Hotelling T2 test and multivariate analysis of variance(MANOVA)were used to analyze nurse job burnout datum. Results There was statistical significance between different cities,different ethnieities in the personal achievements,hut from three dimensions of the whole job burnout,there are no statistical sig-nificant differences among different cities, different ethnicities and different ages. Conclusions The use of Hotelling T2 test and multivariate analysis of variance to analyzing nurse job burnout data, not only ob-tain overall conclusion, and further use of single-variable analysis may also gain comparative results of each dimensions.
2.Analysis of 9 patients with adolescence-onset methylenetetrahydrofolate reductase deficiency
Huiting ZHANG ; Xue MA ; Ying JIN ; Mengqiu LI ; Jinqing SONG ; Zhehui CHEN ; Yi LIU ; Xiangpeng LU ; Hong ZHENG ; Yanling YANG
Chinese Journal of Pediatrics 2024;62(4):357-362
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.
3.Retrospective and cost-effective analysis of the result of Changsha Municipal Public Welfare Program by Noninvasive Prenatal Testing.
Dongbo WANG ; Jun HE ; Yuting MA ; Hui XI ; Meng ZHANG ; Haixia HUANG ; Lijuan RAO ; Binbin ZHANG ; Chunmei MI ; Bo ZHOU ; Zhehui LIAO ; Lei DAI ; Xinyu OUYANG ; Yang ZHANG ; Haiyan WANG ; Xin WANG ; Zhaohui ZHANG ; Sui YAO ; Zhenyu TAN ; Jing YANG ; Wei ZHONG ; Nan WANG ; Jiyang LIU ; Liangrong ZHOU
Chinese Journal of Medical Genetics 2022;39(3):257-263
OBJECTIVE:
To assess the practical and health economical values of non-invasive prenatal test (NIPT) in Changsha Municipal Public Welfare Program.
METHODS:
A retrospective analysis was carried out on 149 165 women undergoing NIPT test from April 9, 2018 to December 31, 2019. For pregnant women with high risks, invasive prenatal diagnosis and follow-up of pregnancy outcome were conducted. The cost-benefit of NIPT for Down syndrome was analyzed.
RESULTS:
NIPT was carried out for 149 165 pregnant women and succeeded in 148 749 cases (99.72%), for which outcome were available in 148 538 (99.86%). 90% of pregnant women from the region accepted the screening with NIPT. 415 (0.27%) were diagnosed as high risk. Among these, 381 (91.81%) accepted amniocentesis, which led to the diagnosis of 212 cases of trisomy 21 (PPV=85.14%), 41 cases with trisomy 18 (PPV=48.81%) and 10 cases with trisomy 13 (PPV=20.83%). The sensitivity and specificity of NIPT for trisomy 21, trisomy 18 and trisomy 13 were (97.70%, 99.98%), (97.62%, 9.97%) and (100%, 99.97%), respectively. In addition, 213 and 30 cases were diagnosed with sex chromosomal aneuploidies (PPV=46.2%) and other autosomal anomalies (PPV=16.57%), respectively. For Down syndrome screening, the cost and benefit of the project was 120.79 million yuan and 1,056.95 million yuan, respectively. The cost-benefit ratio was 1: 8.75, and safety index was 0.0035.
CONCLUSION
NIPT is a highly accurate screening test for trisomy 21, which was followed by trisomy 18 and sex chromosomal aneuploidies, while it was less accurate for other autosomal aneuploidies. The application of NIPT screening has a high health economical value.
Aneuploidy
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Cost-Benefit Analysis
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Female
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Humans
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Noninvasive Prenatal Testing
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Pregnancy
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Retrospective Studies
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Trisomy 18 Syndrome/genetics*
4.Clinical and genetic studies on 76 patients with hydrocephalus caused by methylmalonic acidemia combined with homocysteinuria
Ruxuan HE ; Hui DONG ; Hongwu ZHANG ; Yao ZHANG ; Lulu KANG ; Hui LI ; Ming SHEN ; Ruo MO ; Jinqing SONG ; Yupeng LIU ; Zhehui CHEN ; Yi LIU ; Ying JIN ; Mengqiu LI ; Hong ZHENG ; Dongxiao LI ; Jiong QIN ; Huifeng ZHANG ; Min HUANG ; Rongxiu ZHENG ; Desheng LIANG ; Yaping TIAN ; Hongxin YAO ; Yanling YANG
Chinese Journal of Pediatrics 2021;59(6):459-465
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 χ 2 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.
5.NVP-TNKS656 inhibits the growth of hepatocellular carcinoma cell lines by regulating Hippo signaling pathway
Yu QIAO ; Zhehui HU ; Gang YU ; Beibei DUAN ; Shuai ZHANG ; Yunbo ZHAO ; Zijin ZHANG ; Lin LI
Chinese Journal of Geriatrics 2020;39(6):700-705
Objective:To investigate the effect of a tankyrase inhibitor NVP-TNKS656 on the growth of hepatocellular carcinoma(HCC)cell lines and the involved molecular mechanisms.Methods:Five HCC cell lines were treated with 0, 2.5, 5.0, 10.0 μmol/L of NVP-TNKS656.The cell lines of HLE and HLF were selected and divided into four groups: 0.0 μmol/L(control or DMSO), 2.5 μmol/L, 5.0 μmol/L, 10.0 μmol/L of NVP-TNKS656 groups.Cells were cultured for 48 h for subsequent experiments.Crystal violet staining was used to count the number of the newly formed cell clones.Western blotting was used to detect the protein expression levels of Yes-associated protein(YAP), angiomotin-like 1(AMOTL1)and AMOTL2.The real-time qRT-PCR was used to detect the mRNA expression of YAP and its downstream connective tissue growth factor(CTGF)and cysteine-rich 61(Cyr61). Dual luciferase reporter gene was used to detect the luciferase activity of transcriptional enhancer activator domain(TEAD)family.Results:NVP-TNKS656 inhibited the growth of 5 HCC cell lines in a dose-dependent manner in HLE, HLF, Huh7, MHCC97-H, and MHCC97-L cell lines.There were significant differences in the newly formed cell clone numbers between control(0 μM of NVP-TNKS656)and each of 2.5 μmol/L, 5.0 μmol/L, 10.0 μmol/L of NVP-TNKS656 groups in a dose-dependent manner( F=90.46, 68.58, 191.8, 114.6 and 201.4, all P<0.05). In HLE and HLF cell lines, NVP-TNKS656 significantly reduced the protein level of YAP in a dose-dependent manner and decreased the YAP target gene CTGF(HLE cells: 1.02±0.02, 0.90±0.03, 0.57±0.02, 0.38±0.03, HLF cells: 0.98±0.03, 0.86±0.02, 0.66±0.02, 0.43±0.01)and Cyr61(HLE cells: 1.00±0.01, 0.86±0.02, 0.74±0.03, 0.44±0.03 and HLF cells: 0.99± 0.02, 0.87±0.01, 0.72±0.02, 0.54±0.01)( P<0.05), and inhibited the activity of YAP/TEAD luciferase.At the same time, NVP-TNKS656 up-regulated two major negative regulators of YAP, namely AMOTL1 and AMOTL2 proteins, and promoted the apoptosis of HLE and HLF cells in a dose-dependent manner. Conclusion:NVP-TNKS656 can inhibit the proliferation of HCC by stabilizing AMOTL1/ AMOTL2 and down-regulating the YAP target gene.This study indicates that NVP-TNKS656 can be used as a potential drug for treating HCC.
6.Clinical characteristics and CBS gene analysis of 13 cases with classic homocystinuria
Dongxiao LI ; Zhehui CHEN ; Ying JIN ; Jinqing SONG ; Mengqiu LI ; Yupeng LIU ; Xiyuan LI ; Yongxing CHEN ; Yining ZHANG ; Guoyue LYU ; Liying SUN ; Zhijun ZHU ; Yao ZHANG ; Yanling YANG
Chinese Journal of Pediatrics 2022;60(6):533-538
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 B 6 treatment, while 12 cases were non-responsive. They were mainly treated with low methionine diet and betaine supplement. Three vitamin B 6 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.
7.Clinical features and follow-up study on 55 patients with adolescence-onset methylmalonic acidemia
Xue MA ; Zhehui CHEN ; Huiting ZHANG ; Ruxuan HE ; Qiao WANG ; Yuan DING ; Jinqing SONG ; Ying JIN ; Mengqiu LI ; Hui DONG ; Yao ZHANG ; Mei LU ; Xiangpeng LU ; Huiqian CAO ; Yuqi WANG ; Yongxing CHEN ; Hong ZHENG ; Yanling YANG
Chinese Journal of Pediatrics 2024;62(6):520-525
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.
8.Analysis on life quality of children with high myopia
Zhehui LIU ; Hui XIE ; Jingjing WANG ; Jinliuxing YANG ; Bo ZHANG ; Xiangui HE ; Xun XU
Journal of Shanghai Jiaotong University(Medical Science) 2023;43(12):1548-1553
Objective·To explore the association between high myopia and life quality among children.Methods·Cross-sectional study method was adopted in this study.Highly myopic children aged 4-10 from 16 districts in Shanghai were enrolled through Shanghai Child and Adolescent Large-scale Eye Study-High Myopia Registration Study.Baseline data for spherical equivalent after cycloplegia and questionnaire data in 2020 were collected.Emmetropic children aged 4-10 from 16 kindergartens and elementary schools in Jing'an District and Pudong New Area were enrolled.The uncorrected visual acuity,corrected visual acuity and spherical equivalent without cycloplegia were measured through myopia screening in schools,and the questionnaire on quality of life was filled out.Quality of life was measured by the Strengths and Difficulties Questionnaire(SDQ)and EuroQol Five Dimensions Questionnaire Visual Analogue Scale(EQ-VAS).After describing and testing the differences in variable distributions between the highly myopic children group and the emmetropic children group,the differences in life quality between the two groups,and the association between spherical equivalent and life quality scores of the highly myopic children were examined by a linear regression model.Results·A total of 193 children with high myopia and 209 children with emmetropia were enrolled.There were statistically significant differences in age[(9.58±0.94)years vs(7.63±1.50)years,P<0.001]and gender distribution(46.6%males vs 62.7%males,P=0.00l)between the highly myopic children and emmetropic children.After adjusting for age and gender,it was found that there was no statistically significant difference in SDQ score between the highly myopic children and emmetropic children(β=0.313,95%CI-0.723-1.349,P=0.553),but the EQ-VAS score in the highly myopic children was lower than that in the emmetropic children(β=-3.805,95%CI-6.593--1.017,P=0.008).There was no significant relationship between spherical equivalent and SDQ score(β=0.297,95%CI-0.035-0.628,P=0.079)and EQ-VAS score(β=0.579,95%CI-0.330-1.489,P=0.21 1)in the highly myopic children.Conclusion·In children with high myopia,self-evaluated overall health status reflected by EQ-VAS score is poorer compared with that in children with emmetropia.However,the EQ-VAS score is not associated with the degree of high myopia.
9.Factors affecting phenotypes in the patients with MMACHC gene c. 609G>A homozygous variant cblC type methylmalonic acidemia combined with homocysteinuria
Ruxuan HE ; Ruo MO ; Yao ZHANG ; Ming SHEN ; Lulu KANG ; Zhehui CHEN ; Yi LIU ; Jinqing SONG ; Hongwu ZHANG ; Hongxin YAO ; Yupeng LIU ; Hui DONG ; Ying JIN ; Mengqiu LI ; Jiong QIN ; Hong ZHENG ; Yongxing CHEN ; Haiyan WEI ; Dongxiao LI ; Xiyuan LI ; Rongxiu ZHENG ; Huifeng ZHANG ; Min HUANG ; Chunyan ZHANG ; Yuwu JIANG ; Desheng LIANG ; Yaping TIAN ; Yanling YANG
Chinese Journal of Medical Genetics 2022;39(6):565-570
Objective:To investigate the factors affecting phenotypes in the patients of methylmalonic acidemia combined with homocysteinemia cblC type with MMACHC c. 609G>A homologous variant. Methods:A retrospective study on the clinical manifestations, complications, treatment, and outcome in 164patients of cblC type with MMACHC c. 609G>A homologous variant was conducted.The patients were diagnosed by biochemical and genetic analysisfrom January 1998 to December 2020. Results:Among the 164 patients, 2 cases were prenatally diagnosed and began treatment after birth. They are 3 and 12 years old with normal physical and mental development. Twenty-one cases were diagnosed by newborn screening. Among them, 15 cases had with normal development. They were treated fromthe age of two weeks at the asymptomatic period. Six cases began treatment aged 1 to 3 months after onset. Their development was delayed. One hundred and forty-one cases were clinically diagnosed. Their onset age ranges from a few minutes after birth to 6 years old. 110 cases had early-onset (78.0%). 31 cases had late-onset (22.0%). Five of them died. 24 patients lost to follow-up. Of the 141 clinically diagnosed patients, 130 (92.2%) with psychomotor retardation, 69 (48.9%) with epilepsy, 39 (27.7%) with anemia, 30 (21.3%) had visual impairment, 27 (19.1%) had hydrocephalus, 26 (18.4%) had feeding difficulties, 7 (5.0%) with liver damage, and 5 (3.5%) with metabolic syndrome. The frequency of hydrocephalus and seizures was significantly higher in the early-onset group. The urinary methylmalonic acid increased significantly in the patients with epilepsy. During the long-term follow-up, the level of plasma total homocysteine in the seizure-uncontrolled group was significantly higher than that in the seizure-controlled group, the difference had a statistical significance ( P<0.05). Conclusion:Most of the patients with MMACHC c. 609G>A homozygous variant had early-onset disease, with a high mortality and disability rate. If not treated in time, it will lead to neurological damage, resulting in epilepsy, mental retardation, hydrocephalus, and multiple organ damage. Pre-symptomatic diagnosis and treatment are crucial to prevent irreversible neurological damage. Neonatal screening and prenatal diagnosis are important to improve the outcome of the patients.
10.The phenotypes and genotypes in 314 patients with isolated methylmalonic acidemia
Lulu KANG ; Yupeng LIU ; Ming SHEN ; Zhehui CHEN ; Jinqing SONG ; Ruxuan HE ; Yi LIU ; Yao ZHANG ; Hui DONG ; Mengqiu LI ; Ying JIN ; Hong ZHENG ; Qiao WANG ; Yuan DING ; Xiyuan LI ; Dongxiao LI ; Haixia LI ; Xueqin LIU ; Huijie XIAO ; Yuwu JIANG ; Hui XIONG ; Chunyan ZHANG ; Zhaoxia WANG ; Yun YUAN ; Desheng LIANG ; Yaping TIAN ; Yanling YANG
Chinese Journal of Pediatrics 2020;58(6):468-475
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.