Fatty acid oxidation disorders(FAOD)include more than 10 kinds of diseases,they all belong to autosomal recessive diseases and are common inherited metabolic diseases. Onset age of the patients with FAOD are from newborn to adult. The clinical manifestations were nonspecific,mainly manifested as liver disease,cardiomyopathy and muscle diseases. Detection of free carnitine and acylcarnitines in blood by tandem mass spectrometry and detection of gene mutations are important methods for diagnosis of such diseases. Tandem mass screening for neonatal screening is helpful for early diagnosis and early treatment of FAOD. Primary carnitine deficiency and multiple acyl-CoA dehydrogenase deficiency can be treated by specific therapeutic drugs with good effect. There are no specific drugs for other diseases,which need symptomatic treatment.

()of recessive hereditary diseases caused by the dysfunction of enzymes required for fatty acids to enter mitochondria or fatty acid beta-oxidation,including carnitine transport disorders and fatty acid beta-oxidation disorders. Clinical symptoms are non-specific,involving multiple organs,such as liver,myocardium,skeletal muscle,brain and kidney. Most FAOD patients diagnosed by newborn screening have no clinical symptoms or mild symptoms through early intervention management,but they are prone to acute onset or even sudden death under stress conditions such as hunger and exercise. Long-term follow-up and management can effectively reduce the mortality and morbidity rate of FAOD.

Primary carnitine deficiency is an autosomal recessive hereditary disease caused by the mutation of SLC22 A5 gene,which leads to increased carnitine excretion in urine and low level of carnitine in blood,tissues and cells. Due to the heterogeneity and non-specificity of the clinical manifestations of PCD,it is easy to be misdiagnosed or missed and it is potentially fatal without timely treatment. This disease can be detected early through the newborn screening. Maternal carnitine deficiency and the secondary carnitine deficiency caused by other diseases should be excluded. Genetic test can give a clear diagnosis. Avoiding hunger and use of oral L-carnitine supplementation to maintain normal plasma carnitine concentrations are effective treatments.

Multiple acyl-CoA dehydrogenase deficiency,also known as glutaric aciduria typeⅡ,is an autosomal recessive inherited metabolic disease. It is a mitochondrial electron transport chain and fatty acid metabolism disorder caused by a defect of electron transfer flavoprotein(ETF)or ETF dehydrogenase(ETFDH),resulting in the damage to multiple organs such as myocardia,liver,brain and skeletal muscle. The clinical diagnosis of multiple acyl-CoA dehydrogenase deficiency is difficult due to the lack of specific symptoms and signs of the patients. To make a definitive diagnosis,blood aminoacids and acylcarnitine profiles,urinary organic acids profiles and gene analysis are necessary. According to the response to ribo-flavin(or vitamin B2),multiple acyl-CoA dehydrogenase deficiency could be divided into riboflavin-responsive form and riboflavin-unresponsive form. The riboflavin-responsive form is usually observed in the late-onset cases with good outcome.The patients of riboflavin-unresponsive form usually have early-onset with severe diseases. Bezafibrate, L-carnitine,coenzyme Q10,sodium-D,L-3-hydroxybutyrate and low-fat die should be considered for the treatment. Some patients with riboflavin-unresponsive form show poor outcome.

Medium chain acyl CoA dehydrogenase deficiency is a mitochondrial fatty acid oxidative deficiency disease. It has various clinical manifestations,such as hypoglycemia,lethargy,myasthenia,etc. Different clinical manifestations and atypical biochemical examination can increase the difficulty of diagnosis,which is more likely to result in misdiagnosis. If it is not treated in time,mortality and the rate of sequelae are high,but if confirmed by neonatal screening and treated in time,satisfactory results can be obtained.

Very long chain acyl-CoA dehydrogenase deficiency(VLCADD)is a disorder involving the initial step of fatty acid beta-oxidation in the mitochondrial matrix. VLCADD can present at various ages,from the neonatal period to adulthood,with symptoms including hypoglycemia,rhabdomyolysis,skeletal muscle weakness and cardiomyopathy,and poses the greatest risk of complications during intercurrent illness or after prolonged fasting. Early diagnosis,treatment,and surveillance can reduce mortality. The most common diagnostic evaluation methods are plasma acylcarnitine profiles and ACADVL gene molecular testing. Functional testing,including white blood cell or fibroblast enzyme assay,is a useful diagnostic adjunct if molecular sequencing alone is insufficient to deter-mine the diagnosis or uncharacterized mutations are identified. Treatment emphasizes the avoidance of fasting and often includes a specialized diet that is high carbohydrate/low longchain fat which is supplemented by medium chain triglycerides(MCT).very-long chain acyl coenzyme A dehydrogenase

myocardium. Fatty acid oxidation disorders(FAODs)can give rise to insufficiency of mitochondrial energy production and accumulation of metabolic intermediates in cardiomyocytes,such as lipid and long-chain acyl carnitine,leading to myocardial lesions.FAODs include carnitine-dependent fatty acid transport disorders and mitochondrial fatty acid beta-oxidation disorders,with any enzyme or transporter defect in fatty acid oxidation process resulting in this disease. Although FAODs are one of the rare causes of pediatric cardiomyopathy,some patients with FAODs are expected to have cardiomyopathy alleviated and quality of life improved by early correction of fatty acid metabolic disorders.

OBJECTIVE:(DMD),summarize the gene mutation hotspots in 97 cases and to explore the correlation between clinical manifestations and genotype. METHODS: Totally 97 patients with DMD diagnosed by genetic examination from January 2014 to 2018 were collected and analyzed. The clinical manifestations,serum analyses and gene mutation results were analyzed. RESULTS: The main clinical manifestations of 97 patients(96 boys)were feeding difficulties,increased muscle enzyme and limb weakness.Creatine kinase(CK),lactate dehydrogenase(LDH)and aspartate aminotransferase(AST)muscle enzymes were significantly increased. By combining deep-sequencing technologies,the large deletions of DMD gene mutation was in 62 cases(63.92%);there were 11 cases(11.34%)of large duplication mutation,and 24 cases(24.74%)of point mutation. All of the mutations could occur in any position in the DMD gene,but there were two hot spots;45 cases were located in the central region gene exon 45～55(72.58%);12 cases of deletion mutation were located in 5'exon end exon 2～19 area(19.35%). CONCLUSION: The main clinical manifestations of the DMD children are feeding difficulty,increased muscle enzyme and limb weakness.The patients with significantly increased muscle enzyme should receive a timely defection of DMD gene.

OBJECTIVE: To observe the efficacy and safety of tocilizumab against refractory systemic onset juvenile idiopathic arthritis(SoJIA). METHODS: A prospective follow-up study of 16 patients with refractory active SoJIA patients with or with tocilizumab after treatment of clinical disease activity indicators and safety. The ANOVA was used for statistical analysis. RESULTS: After 2 weeks,12 weeks and 52 weeks of treatment,the levels of white blood cells,erythrocyte sedimentation rate and hypersensitive C-reactive protein were significantly decreased,and there were statistically significant differences(F=26.25、145.70、517.96,P<0.05). JADAS27 was significantly decreased after 2 weeks,12 weeks and 52 weeks of treatment with tocilizumab(the score being 23.09±3.46,8.19±2.63,4.25±2.86 and 2.63±1.54),the difference being statistically significant(P<0.05). Some children had adverse reactions,2 cases of skin abnormalities,1 case of white pityriasis,1 case of skin infection;3 cases of liver enzyme abnormalities;2 cases of leukopenia. CONCLUSION: Tocilizumab can improve the condition of children with SoJIA in rapid and obvious way,and medium and longterm security and tolerance was good. The duration of tocilizumab therapy should be carefully assessed.

OBJECTIVE: To investigate diagnosis of children's neuronal ceroid lipofuscinosis(NCL),especially the significance of gene diagnosis. METHODS: The clinical data of 5 cases of suspected NCL in our hospital from January 2013 to January 2017 were retrospectively analyzed. There were 3 boys and 2 girls,2 of whom were sister and brother. The age of onset ranged from 3 years and 4 months to 8 years and 1 month,averaged 5 years and 9 months. The first visit to our hospital ranged from 3 years and 6 months to 14 years,with an average of 8 years and 1 month. DNA of peripheral blood was extracted from 4 children with abnormal imaging and their parents and brothers,and the related genes were detected.RESULTS: Four cases of children were diagnosed with NCL,and 1 case was diagnosed with hysteria;gene detection showed:case 1:TPP1 gene c.887-17 A>G was a shearing variant,and c.646 G>A was a missense mutation;case 2:TPP1 gene c.1015＿1016 del was frameshift mutation,and c.640 C>T was nonsense mutation;the nucleotide of case 3:CLN6 gene changed to c.158 T>C(p.L53 P)and c.889 C>T(p.P297 S). The parents of the 3 cases only carried one of the heterozygous variants,and the brother of case 3 had no mutation. Heterozygous mutation existed in case 4:CLN3 gene,c.1160＿1169 delCAGCCTACGTinsGC,which was not detected in the mother,and there was the deletion of the paternal sample;there was loss of heterozygosity in the exon E3-E8 of the CLN3 gene,which was the true missing from mother.Five cases were followed up for 15-60 months and there was no death. CONCLUSION: Suspected NCL patients should be checked head MRI,electroencephalogram and gene. The gene mutation leads to NCL,such as TPP1(c.887-17 A>G,c.1015＿1016 del),CLN3(c.1160＿1169 delCAGCCTACGTinsGC),CLN6[(c.158 T>C(p.L53 P) and c.889 C>T(p.P297 S)],are reported for the first time. Genotype is very important for NCL classification and prognosis.