OBJECTIVE To provide direction and reference for the adjustment of the discount rate （DR） in China’s pharmacoeconomic guidelines. METHODS Search was conducted on the official websites of the International Society for Pharmacoeconomics and Outcomes Research， health technology assessment agencies in various countries/regions， as well as relevant websites of other upper-middle-income or high-income countries/regions. The recommended DR， adjustment trends， and setting rationales in pharmacoeconomic evaluation guidelines across different countries/regions were then summarized and compared. Based on theoretical derivation and literature analysis， the effects of different DR on the incremental cost-effectiveness ratio （ICER） were examined. RESULTS & CONCLUSIONS Among the 40 included guidelines， the base-case DR ranged from 1.5% to 5%， with 5% being the most common value； the range for sensitivity analysis was 0 to 12%. Thirty-six countries/regions applied the same DR to both costs and health outcomes， while in the Netherlands， Belgium， Poland and Czech Republic， DR for costs was higher than for health outcomes. In recent years， Korea， France and Ireland had lowered their DR in response to economic changes， whereas the Netherlands and Czech Republic had raised their DR for cost. The setting of the DR was primarily based on the public project investment interest rate or referred to recommendations from internationally authoritative institutions and other relevant guidelines. The direction and magnitude of the impact of different DR on the ICER largely depended on the distribution of costs and health outcomes between the intervention and reference measure. The setting and adjustment of DR were closely associated with the economic environment. Based on international experience, the DR in China can be lowered by 0.5% to 1.5%， and localized empirical research can be conducted using internationally common estimation methods.

Objective:To investigate the clinical characteristic and genetic variants of children with carnitine palmitoyltransferase 2(CPT2)deficiency.Methods:The clinical and genetic data of 6 children with CPT2 deficiency were retrospectively analyzed.The blood acylcarnitines and genetic variants were detected with tandem mass spectrometry and whole-exon gene sequencing,respectively.Results:There were 4 males and 2 females with a mean age of 32 months(15 d-9 years)at diagnosis.One case was asymptomatic and with normal laboratory test results,2 had delayed onset,and 3 were of infantile type.Three cases were diagnosed at neonatal screening,and 3 cases presented with clinical manifestations of fever,muscle weakness,and increased muscle enzymes.Five children presented with decreased free carnitine and elevated levels of palmitoyl and octadecenoyl carnitines.CPT2 gene variants were detected at 8 loci in 6 children(4 harboring biallelic mutations and 2 harboring single locus mutations),including 3 known variants(p.R631C,p.T589M,and p.D255G)and 5 newly reported variants(p.F352L,p.R498L,p.F434S,p.A515P,and c.153-2A>G).It was predicted by PolyPhen2 and SIFT software that c.153-2A>G and p.F352L were suspected pathogenic variants,while p.R498L,p.F434S and p.A515P were variants of unknown clinical significance.Conclusions:The clinical phenotypes of CPT2 deficiency are diverse.An early diagnosis can be facilitated by neonatal blood tandem mass spectrometry screening and genetic testing,and most patients have good prognosis after a timely diagnosis and treatment.

Objective:To analyze regional differences in MMACHC gene variations among patients with cblC-type methylmalonic acidemia (MMA) in China and to explore the relationship between these variations and neonatal screening, biochemical markers and prognosis.Methods:Retrospective case summary. Clinical and laboratory data, including general condition, biochemical markers and genetic analysis, were collected from 1 859 cblC MMA patients from 2005 to 2023. Patients were divided into 7 groups according to their regions: north China, northeast China, east China, central China, south China, southwest China and northwest China. They were also classified into neonatal screening and non-neonatal screening groups. Mann-Whitney U and Kruskal-Wallis tests were used to compare biochemical marker levels. In contrast, the Chi-square test was applied to compare MMACHC gene variant frequencies, neonatal screening proportion, onset age and prognosis between groups. Results:Among 1 859 cases of cblC MMA, 1 019 were male and 840 were female, with a consultation age of 1.0 (0.1, 5.0) month. A total of 1 787 cases carried compound heterozygous or homozygous variants and only 1 variant site was identified in 72 cases. The 10 most frequent variants were c.609G>A (1 238 cases), c.658_660delAAG (343 cases), c.80A>G (284 cases), c.482G>A (239 cases), c.567dupT (191 cases), c.656_658delAGA (131 cases), c.217C>T (109 cases), c.394C>T (105 cases), c.445_446delTG (51 cases) and c.1A>G (50 cases). The frequency of the c.609G>A was the lowest in northwest China (28.8% (44/154), χ2=-18.42, P<0.05). The frequency of the c.567dupT was the most common in southwest China (25.0% (20/80), χ2=71.70, P<0.001) and c.656_658delAGA had the highest frequency in northeast China (9.3% (19/205), χ2=32.08, P<0.001). Non-missense variants (91.2% (62/68), 88.5% (46/52)) and early-onset patients (90.0% (36/40), 94.4% (34/36)) were both more prevalent in southwest and south China ( χ2=14.95, 31.69, both P<0.05). The proportion of neonatal screening was the lowest in south China (22.2% (8/36), χ2=98.48, P<0.05), where the mortality rate was the highest (19.1% (4/21), χ2=38.98, P<0.001). East China exhibited the highest frequency of missense variants (21.5% (339/1 579)), the highest proportion of patients identified through neonatal screening (54.5% (465/853)), and a more significant proportion of patients with good prognosis (36.6% (227/621), χ2=14.57, 93.49, 38.98, all P<0.05). In addition, the c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods (8.3% (132/1 586) vs. 5.9% (122/2 060), χ2=7.97, P<0.05). Conclusions:The frequency of MMACHC gene variation varies across different regions. The c.609G>A was least frequent in northwest China, c.567dupT was most common in southwest China, and c.656_658delAGA was most prevalent in northeast China. South China had the lowest neonatal screening rate and the highest mortality. At the same time, east China exhibited the highest frequency of missense variants, the highest proportion of patients identified through neonatal screening and the best prognosis. The c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods.

OBJECTIVE: To explore the disease spectrum for abnormal 3-hydroxyisovalerylcarnitine (C5OH) metabolism identified through newborn screening and clinical diagnosis patients and the key points for differential diagnosis so as to raise the awareness of pediatricians for such diseases. METHODS: Clinical data of 85 neonates with abnormal C5OH metabolism identified from February 2004 to January 2022 at Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were collected. Their clinical manifestations and results of tandem mass spectrometry (MS/MS), gas chromatography mass spectrometry (GC-MS) and genetic testing were retrospectively analyzed. RESULTS: Among the 85 cases, 46 (54.1%) were identified by neonate screening, whilst 39 (45.9%) were clinically diagnosed patients. Five diseases were diagnosed, including 28 cases with multiple carboxylase deficiency (MCD, 32.9%), 29 cases with 3-methylcrotonyl-coenzymeAcarboxylasedeficiency (MCCD, 34.1%), 4 cases with 3-methylglutaconic acid (3-MGA, 4.7%), 7 cases with 3-hydroxy-3-methylglutaric acid (3-HMG, 8.2%), and 17 cases with beta-ketothiolase deficiency (BKD, 20.0%). The disorders were characterized by sudden onset, anorexia, vomiting, diarrhea, abnormal breathing, consciousness disorder, spasm and developmental delay. CONCLUSION Among newborns with abnormal C5OH metabolism, MCCD is the most common disorder, which was followed by BKD and MCD. For patients with abnormal C5OH metabolism, MCD is the most common, followed by BKD and 3-HMG. C5OH related diseases have great heterogeneity. Combination of blood acylcarnitine levels, urinary organic acid levels and genetic testing based on clinical characteristics can help to attain the diagnosis.
Humans ; Infant, Newborn ; China ; Neonatal Screening ; Retrospective Studies ; Tandem Mass Spectrometry/methods*

Objective:To analyze the disease spectrum of lysosomal storage disorders(LSDs) and explore the prevalent distributions of different LSD types in one center in Shanghai.Methods:A retrospective analysis was made.A total of 5 476 suspected LSD patients, including 3 415 males and 2 061 females, with a median age of 4 years(1 day to 72 years), were collected from Xinhua Hospital, Shanghai Jiaotong University School of Medicine from August 2008 to May 2022.The activity of different lysosomal enzymes was detected by fluorescent and biochemical methods.Results:A total of 1 520 patients were diagnosed with LSDs, including 972 males and 548 females, with a median age of 4 years(1 day to 59 years), involving 19 different subtypes.Mucopolysaccharidosis(MPS) was the most common type among LSDs, with a frequency of 45.46%(691/1 520), followed by sphingolipidoses [33.88%(515/1 520)] and glycogen storage disease type Ⅱ [16.05%(244/1 520)] successively.MPS Ⅱ was the most common type in MPS, with a frequency of 45.73%(316/691), followed by MPS ⅣA [22.87%(158/691)]. Niemann-Pick A/B, Gaucher, and Krabbe diseases were common in Sphingolipidoses patients, with frequencies of 37.09%(191/515), 34.37%(177/515), and 10.29%(53/515), respectively.Conclusions:LSDs are common genetic metabolic diseases, especially MPS and sphingolipidoses.Newborn screening for LSDs should be carried out timely so that the patients can be treated early and their prognosis can be improved.

Objective:To investigate the spectrum of amino acid, organic acid, and fatty acid oxidative metabolic diseases in children diagnosed by detecting urinary organic acid levels using gas chromatography-mass spectrometry.Methods:From January 2005 to December 2021, clinical data of 2 461 children diagnosed with inherited metabolic diseases (IMD) by gas chromatography-mass spectrometry, in combination with tandem mass spectrometry and genetic testing in Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were retrospectively analyzed.Results:Among 2 461 children, 1 446 were male and 1 051 were female. A total of 32 types of IMD were detected among 2 461 patients, which included 10 amino acid disorders in 662 cases (26.9%), 6 common diseases were hyperphenylalaninemia, citrin deficiency, ornithine carbamoyltransferase deficiency, maple syrup urine disease, alkaptonuria, and tyrosinemia-I, 17 types of organic acidemias in 1 683 cases (68.4%), 6 common diseases were methylmalonic acidemia, propionic acidemia, valeric acidemia-type Ⅰ, isovaleric acidemia, 3-methylcrotonyl-CoA carboxylase deficiency and multiple carboxylase deficiency and 5 fatty acid β oxidative defects in 116 cases (4.7%), 2 common diseases were multiple acyl-CoA dehydrogenase deficiency and short-chain acyl-CoA dehydrogenase deficiency).Conclusion:Among the diseases diagnosed by analyzing urinary organic acid profiling with gas chromatography-mass spectrometry, the most common are organic acidemias, followed by amino acid disorders and fatty acid oxidation defects.

Objective:To investigate the treatment and prognosis of children with propionic acidemia (PA).Methods:This study involved 82 children with PA treated in the Department of Pediatric Endocrinol-ogy and Genetic Metabolism, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine from December 2002 to June 2020. Clinical data, including manifestations, laboratory test results, treatment strategy, and follow-up data, were summarized and analyzed using t-test or Mann-Whitney U test. Results:(1) Among the 82 cases consisting of 50 (61.0%) boys and 32 (39.0%) girls, 59 (72.0%) were diagnosed after clinical onset; 22 (26.8%) were diagnosed by newborn screening, including eight asymptomatic ones; the other one (1.2%) was asymptomatic but confirmed after the diagnosis of PA in the patient's sibling. The average age at first onset was 4.5 months (2 d-5 years) in 73 subjects, of which 28 (38.4%) were early-onset PA (within three months after birth). (2) Cranial MRI was performed on 26 cases, and abnormality was identified in 19 (73.1%) cases. (3) Hyperlactatemia was found in 16 cases among 30(53.3%) who underwent relevant examination with the average lactic acid level of 3.5 (2.1-4.3) μmol/L, while 35 out of 40 patients (87.5%) had hyperammonemia with an average blood ammonia level of 105.4 (34-907) μmol/L. (4) Among the 28 early-onset PA cases, 16 (57.1%) died, and 12 (42.9%) survived. There was no significant difference in the serum propionylcarnitine level, propionylcarnitine to acetylcarnitine ratio, urine 3-hydroxypropionic acid, or methylcitrate level between the survival and death cases. (5) Genetic mutations were detected in 75 patients (91.5%), among which 26 (34.7%) carried PCCA gene mutations and 48 (64%) with PCCB gene mutations. One patient (1.3%) harbored one known pathogenic mutation in each of the PCCA and PCCB genes. All mutations were inherited from the parents. (6) Followed up to June 2020, 57 (69.5%) patients survived, and 25 (30.5%) died from multiple organ failure secondary to severe acidosis, including 16 early-onset and nine late-onset cases. Conclusions:The primary treatment of PA is dietary control. Most PA patients are diagnosed after clinical onset, but symptoms may recur and even have developmental retardation despite treatment. Some of those diagnosed through newborn screening are asymptomatic after treatment. Newborn screening using tandem mass spectrometry is recommended for early diagnosis and treatment of PA.

Objective:Nuclear magnetic resonance spectroscopy (NMR) was used to detect the species and content of metabolites in urine of patients with inherited metabolic diseases, and to explore the application value of NMR technology in the diagnosis of inherited metabolic diseases.Methods:Urine samples were collected from 20 patients with inherited metabolic diseases diagnosed in Xinhua Hospital, Shanghai Jiaotong University School of Medicine from March to June 2019, including 9 cases of methylmalonic acidemia (MMA). NMR pulse length-based concentration determination and Gas chromatography mass spectrometry (GC/MS) semi-quantitative method were used to detect the composition of metabolites in urine samples of patients with inherited metabolic diseases, and the levels of abnormal metabolites in the two methods were analyzed.Results:NMR technology can detect the levels of characteristic metabolites significantly increased in the urine of patients with MMA, isovalerinemia, glutaric acidemia, propionic acidemia, 3-methylcrotonyl-CoA carboxylase deficiency, ornithine carbamyltransferase deficiency, Citrin deficiency, Canavan disease, tyrosinemia and lysinuria protein intolerance. The average is 8 times of the upper limit of the reference value, and the highest is 545 times. Compared to GC/MS, NMR technology can detect the levels of various metabolites such as organic acids, amino acids and sugars. In 9 cases of untreated MMA,the median levels of methylmalonic acid and 3-hydroxypropionic acid in NMR [1 800 (180-12 000) and 50 (0-270) mmol/mol Cr] were higher than the reference values (0-31, 0-35). The median levels of methylmalonic acid and methylmalonic acid in GC/MS [136.56 (43.79-518.67) and 4.87 (1.52-7.52)] were higher than the reference values (0-4 and 0-0.7).Conclusions:NMR and GC/MS technologies are specific for the diagnosis of organic acidemia. The primary component detected by GC/MS is organic acid. NMR technology can break through this limitation and measure the level of various metabolites in urine, which provides a more theoretical basis for the diagnosis and research of inherited metabolic disease.

Objective To explore the clinical feature,genetic variant and clinical outcome of patients with cblA-type methylmalonic acidemia (MMA).Methods Clinical manifestations,therapeutic schedule and prognosis of 12 patients with cblA-type MMA were analyzed.MMAA gene variants were analyzed for all patients and their parents.Results Vomiting,dyspnea and drowsiness were the major clinical features of cblA-type MMA.Eleven patients were vitamin B12-responsive.After treatment,the blood level of propionylcarnitine,ratio of propionylcarnitine/acetylcarnitine,urine level of methylmalonic acid and methylcitric acid have decreased significantly (P＜0.05).Follow-up study showed that 8 patients (66.7％)had normal development,while the rest (33.3％) remained to have various level of mental or movement delay.Fourteen MMAA gene variants were detected,with c.365T＞C (p.L122P) being the most common (29.2％).Six novel variants,including c.54delA (p.A19Hfs * 43),c.275G＞A (p.G92V),c.456delT (p.G153Vfs* 8),c.667dupA (p.T223Nfs* 4),c.1114C＞T (p.Q372X) and c.1137_1138delCA (p.F379Lfs * 27) were found.Conclusion The main clinical manifestations of patients with cblA-type of MMA include vomiting,dyspnea and drowsiness.Most patients are vitamin B12-responsive.c.365T＞C is a potential hot spot variant of MMAA gene in China.

Objective To explore the clinical manifestations, treatment and outcomes of patients with c. 482G>A ( p. R161Q ) variant of MMACHC gene in cblC type methylmalonic acidemia ( MMA ) . Methods The clinical manifestations, mass spectrometry results, genotypes, treatment and outcomes of 75 patients with cblC type MMAcarryingc.482G>A(p.R161Q)variantwereretrospectivelyanalyzed.Results Ofthe75patients,57(76％) were from newborn screening and one of them had an onset. Among the rest 18 unscreened patients, 2 were diagnosed after their full sisters' or brothers' diagnosis, the others were clinical patients. There were 17 clinical patients, with the medium age of onset 12 years old (10 days～26 years old). 12 late onset patients (70.6％) presented with poor academic performance, memory loss, poor expression, and decreased exercise capacity, while 5 early onset patients (29.4％) presented with convulsion and delay of development. All patients were vitamin B12-responsive. The levels of blood propionylcarnitine, the ratio of propionylcarnitine to acetylcarnitine, urinary methylmalonic acid and methyldecanoic acid, and plasma homocysteine were significantly decreased after treatment (P< 0.01). All patients diagnosed from newborn screening had normal development. However, only 3 clinical patients had a rather normal outcomes and the others remained different levels of intelligence and ( or ) motor dysfunction after treatment. Conclusion The c.482G>A ( p. R161Q) variant of MMACHC gene is associated with late onset cblC type MMA. Patients with this variant have a better response to hydroxycobalamin than other variants. The outcome of patients diagnosed from the newborn screening is good. When symptoms occur, the disability rate is often high. Therefore, newborn screening is a recommended method to prevent this disease.