ObjectiveBiochemistry and Molecular Biology, a discipline that elucidates life phenomena at the molecular level, serves as a core foundational course in medical education. It provides the theoretical basis for studying other basic and clinical medical subjects, as well as for understanding pathogenesis, disease diagnosis, and treatment. However, its complex content and highly abstract concepts have posed a dual challenge to traditional teaching models: “inefficient instruction” and “inadequate learning outcomes”. Within limited classroom hours, how to engage students and stimulate their intrinsic motivation, and how to help them recognize, understand, and develop a passion for biochemistry from the perspective of the discipline’s essence, have long been key focuses of curriculum research. MethodsUsing the lipid metabolism chapter as an example, this study employs “Rain Classroom”, a generative artificial intelligence (AI)-assisted platform, to support education in four dimensions: teaching, learning, evaluation, and research. In teaching, it assists instructors through virtual experiments, lesson preparation support, knowledge mapping, and assignment design. For learning, it serves as an intelligent study assistant for students, providing automated assignment review, enabling educational resource sharing, and facilitating personalized learning pathways. In evaluation, the platform automates assignment grading, analyzes student performance data, and offers diagnostic feedback and teaching recommendations. In research, it aids educators in collecting and analyzing teaching data, as well as searching for and summarizing relevant literature. ResultsThe results indicate that an educational model integrating teacher-led instruction, student-centered learning, and generative AI assistance significantly enhances teaching quality, students’ self-directed learning abilities, and knowledge mastery. Furthermore, with the support of generative AI, curriculum-based ideological education—focusing on cutting-edge disciplinary advances and topical medical issues—helps cultivate students’ medical spirit of “honoring life and healing the wounded”, thereby fostering the establishment of appropriate professional values. Finally, while generative AI presents both opportunities and challenges for higher education, this study also analyzes potential risks in its teaching applications, emphasizing the need for both instructors and students to avoid over-reliance and to ensure that technological tools consistently serve the fundamental goals of education. ConclusionThis study demonstrates that integrating generative AI, specifically via the “Rain Classroom” platform, can effectively enhance biochemistry education. By supporting teaching, learning, evaluation, and research, this approach improves both educational effectiveness and student outcomes. It also facilitates the incorporation of cutting-edge knowledge and professional ethics, nurturing a patient-centered mindset. Additionally, the study addresses potential implementation risks to ensure that such technological tools remain aligned with the core purpose of education.

ObjectiveTo evaluate the therapeutic effect of Huazhuo SanJie Chubi presciption （HSCD） on chronic gouty arthritis （CGA） rats with low-grade inflammation and to explore the underlying mechanism with a focus on macrophage polarization. MethodsThe 41 male 6-week-old SD rats were randomly allocated， using the random number table， to a normal group （n=8） and a model group （n =33）. CGA with low-grade inflammation was induced in the model group by daily gavage of potassium oxonate （250 mg·kg^-1·d^-1） and hypoxanthine （300 mg·kg^-1·d^-1）， combined with intra-articular injection of a monosodium urate （MSU） crystal suspension （50 μL， 25 g·L^-¹） into the left ankle twice weekly. After 4 weeks of modeling， 3 rats were randomly selected from each group for model validation. The remaining successfully modeled rats were randomly divided into a model group， an HSCD group （10.35 g·kg^-1·d^-1， gavage once daily）， an M1 polarization agonist group （L-methionine sulfoximine， 300 mg·kg^-1， subcutaneous injection every other day）， an M1 polarization agonist + HSCD group， an M2 polarization inhibitor group （PD0325901， 10 mg·kg^-1·d^-1， gavage once daily）， and M2 polarization inhibitor + HSCD group. The corresponding drug or drug combination was administered according to group assignment， whereas rats in the normal and model groups received 0.5% carboxymethyl cellulose sodium （CMC-Na） vehicle （10.35 g·kg^-1·d^-1， gavage once daily）. All interventions were continued for four weeks. During the intervention period， except for the normal group， potassium oxonate （250 mg·kg⁻¹） and hypoxanthine （300 mg·kg^-1） were co-administered by gavage every other day to maintain the model. At the end of treatment， serum uric acid （SUA）， ankle joint diameter and joint swelling index were measured. The levels of high-sensitivity C-reactive protein （hs-CRP）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， chemokine C-C motif ligand 2 （CCL2）， S100 calcium-binding protein A8/A9 （S100A8/A9）， interleukin-10 （IL-10） and arginase-1 （Arg-1） in serum and joint fluid were determined by enzyme-linked immunosorbent assay （ELISA）. High-frequency ultrasound was used to assess MSU deposition in the ankle joint. Hematoxylin-eosin （HE） staining was performed to evaluate synovial histopathological changes. Quantitative Real-time PCR and immunofluorescence were used to detect the mRNA and protein expression of the M1 macrophage polarization markers inducible nitric oxide synthase （iNOS） and the M2 macrophage polarization marker scavenger receptor cysteine-rich type 1 protein M130 （CD163） in synovial tissue. ResultsCompared with the normal group， the model group showed significantly elevated SUA level and joint swelling index， and increased levels of pro-inflammatory cytokines， CCL2， and S100A8/A9 in both serum and joint fluid （P<0.05）， accompanied by MSU deposition and synovial inflammation in the ankle joint. The mRNA and protein expression levels of macrophage polarization M1/M2 markers iNOS and CD163 in synovial tissues were also significantly up-regulated （P<0.05）. Compared with model group， rats in HSCD group had significantly lower SUA levels， attenuated joint swelling， reduced serum levels of pro-inflammatory cytokines， and decreased levels of CCL2 and S100A8/A9 in both serum and joint fluid， accompanied with alleviated MSU deposition and synovial inflammation （P<0.05）. HSCD markedly downregulated the mRNA and protein expression of M1 marker iNOS （P<0.05）， whereas it had no significant effect on the expression of M2 marker CD163. Compared with the M1 polarization agonist group， the M1 polarization agonist + HSCD group showed significantly reduced joint swelling， lower serum levels of pro-inflammatory cytokines， and decreased levels of CCL2 and S100A8/A9 in joint fluid （P<0.05）. In addition， synovial inflammatory cell infiltration and angiogenesis were attenuated， and iNOS mRNA and protein expression levels were significantly reduced （P<0.05）. Compared with the M2 polarization inhibitor group， the M2 polarization inhibitor + HSCD group exhibited reduced joint swelling， decreased levels of CCL2 and S100A8/A9 in joint fluid and ameliorated synovial inflammation （P<0.05）， whereas the levels of anti-inflammatory mediators （IL-10， Arg-1） and CD163 mRNA and protein expression were not significantly increased. ConclusionHSCD alleviates low-grade inflammation in CGA rats， at least in part， by inhibiting macrophage polarization toward the M1 phenotype.

ObjectiveThis paper aims to observe the effect of Huazhuo Sanjie Chubi prescription （HSCD） on the gouty bone erosion model rats and investigate its action mechanism. MethodsThirty-six two-month-old male SD rats were randomly divided into the blank group with nine rats and the modeling group with 27 rats. The rats in the modeling group were administered hypoxanthine solution at 300 mg·kg^-1·d^-1 and potassium oxonate solution at 250 mg·kg^-1·d^-1， combined with intra-articular injection of 200 μL monosodium urate （MSU） crystal suspension at 25 g·L^-1 into the right ankle joint （joint injection once every three days）， so as to induce the gouty bone erosion model. After four weeks of modeling， three rats were selected from these two groups to validate the model. The modeled 24 rats were randomly divided into the model group， HSCD group （10.35 g·kg^-1·d^-1）， allopurinol group （20 mg·kg^-1·d^-1）， and inhibitor group （LY294002， 10 mg·kg^-1·d^-1）， with six rats per group. Except for the blank group， rats in all other groups continued to receive hypoxanthine solution at 300 mg·kg^-1 and potassium oxonate solution at 250 mg·kg^-1 via gavage concurrently with administration to maintain modeling intervention. The rats in the HSCD group and allopurinol group received administration by gavage at the above doses. The rats in the inhibitor group received an intraperitoneal injection at the above dose. The rats in the blank group and model group received saline （10.35 g·kg^-1·d^-1） by gavage for four consecutive weeks. After administration， ankle joint swelling of the rats in all groups was observed， and the diameters were measured. Bone volume fraction （BV/TV） and bone surface area to bone volume （BS/BV） were observed and quantitatively analyzed by Micro-CT. Histopathological changes in the ankle joint were observed by hematoxylin-eosin （HE） staining and safranin O-fast green staining. The uric acid in the rats' serum was determined by enzyme colorimetry. The levels of inflammatory factors， including tumor necrosis factor-α （TNF-α）， interleukin （IL）-1β， and IL-6 were measured by enzyme-linked immunosorbent assay （ELISA）. The protein expressions of receptor activator of nuclear factor-κB ligand （RANKL） and phosphorylated （p）-phosphatidylinositol-3-kinase （PI3K） in ankle joint tissues of rats were detected by immunofluorescence staining. The mRNA levels of the proteins related to the bone erosion， including RANKL， tartrate-resistant acid phosphatase （TRAP）， cathepsin K （CTSK）， and matrix metalloproteinase-9 （MMP-9） in the ankle joint tissues of rats were determined by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. The expressions of the proteins related to the bone erosion， including RANKL， CTSK， TRAP， MMP-9， and the proteins related to the PI3K/protein kinase B （Akt） signaling pathway， including PI3K， Akt， mammalian target of rapamycin （mTOR）， p-PI3K， phosphorylated protein kinase B （p-Akt）， and phosphorylated mammalian target of rapamycin （p-mTOR）， were detected by Western blot. ResultsCompared with the blank group， the modeling group showed marked ankle swelling and increased diameter. Micro-CT revealed an uneven articular surface and honeycomb-like bone erosion in the ankle joint. Quantitative analysis showed decreased BV/TV and increased BS/BV （P<0.05）. HE staining revealed a narrowed joint space， rough and discontinuous cartilage surfaces， reduced and unevenly distributed chondrocytes， partial hypertrophy， and blurred tidemarks， confirming successful model establishment. After four weeks of intervention， compared with those in the blank group， the rats in the model group exhibited severe ankle swelling and increased diameters （P<0.05）. Micro‑CT showed that the ankle joint surface was irregular， and bone erosion exhibited a honeycomb‑like morphology. The microstructural parameters of the bone revealed a decreased BV/TV and an increased BS/BV （P<0.05）. Histopathological examination revealed a narrowed joint space and severe articular cartilage destruction. The levels of uric acid in the serum and inflammatory factors （IL-1β， IL-6， and TNF-α） were increased （P<0.05）. The mRNA and protein levels of the proteins related to bone erosion in joint tissue， including RANKL， CTSK， TRAP， and MMP-9， were upregulated （P<0.05）. The ratios of p-PI3K/PI3K， p-Akt/Akt， and p-mTOR/mTOR in the proteins related to the PI3K/Akt signaling pathway were increased （P<0.05）. RANKL and p-PI3K protein fluorescence intensities were elevated （P<0.05）. Compared with those in the model group， the above indicators in all other administration groups showed varying degrees of improvement. The HSCD group and inhibitor groups exhibited more significant effects in reducing ankle swelling， improving bone erosion， bone microstructure （significant decrease in BV/TV and increase in BS/BV）， and the pathology of cartilage erosion， lowering inflammatory factor levels， downregulating the proteins related to the bone erosion， and suppressing activation of the PI3K/Akt/mTOR pathway （P<0.05）. The uric acid levels in rats' serum were reduced in both HSCD and allopurinol groups （P<0.05）. Compared with those in the HSCD group， the rats in the allopurinol group had larger ankle diameters （P<0.05）， more severe bone erosion and bone microstructure damage （P<0.05）， worse improvement of the pathology of cartilage erosion， higher levels of IL-6 and TNF-α （P<0.05）， elevated expressions of the proteins related to the bone erosion， higher expression ratio of proteins related to the PI3K/Akt signaling pathway （P<0.05）， and higher fluorescence intensities of RANKL and p-PI3K proteins （P<0.05）. The inhibitor group achieved comparable results to the HSCD group in improvements of bone microstructure and the reduction of IL-1β and IL-6， stronger suppression of TNF-α and PI3K/Akt/mTOR signaling pathway activation （P<0.05）， but weaker effects on cartilage repair and serum uric acid reduction （P<0.05）. ConclusionHSCD effectively reduces uric acid levels in serum， suppresses inflammatory factor secretion， and downregulates the expressions of proteins related to bone erosion， including RANKL， CTSK， TRAP， and MMP-9 in the joint tissues. Its action mechanism of improving gouty bone erosion may be associated with inhibition of the PI3K/Akt signaling pathway.

Background: and Purpose Vertebrobasilar fusiform aneurysms (VBFAs) carry substantial morbidity and mortality, but optimal management for unruptured VBFAs remains unclear. We compared the safety and efficacy of conservative management (CM), stent-assisted coiling (SAC), and flow diverters (FDs) in patients with unruptured VBFAs, focusing on long-term prognosis. Methods: This study included data from a nationwide Chinese cohort of patients with vertebrobasilar dissecting aneurysms. Inverse probability of treatment weighting (IPTW) balanced confounders across groups. The primary outcome was poor prognosis (modified Rankin Scale score >2). Secondary outcomes included aneurysm rupture, ischemic stroke, compression symptoms, and VBFA-related deaths. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analyses were performed. Results: Among 1,115 patients with unruptured VBFAs, 838 (median age, 54 years; 655 men) were included. After IPTW, baseline characteristics were balanced. Median follow-up was 54 months. FD was associated with a lower risk of poor prognosis than CM (OR, 0.48 [95% CI, 0.30 to 0.77]; p=0.002), with no difference between CM and SAC. FD also reduced aneurysm rupture (OR, 0.20 [95% CI, 0.07 to 0.60]; p=0.004) and compression symptoms (OR, 0.30 [95% CI, 0.13 to 0.68]; p=0.004) versus CM. Time-to-event analyses further revealed significant differences in vertebral artery lesions and Type I–II VBFAs, whereas no significant differences were observed in basilar or vertebrobasilar junction lesions or in Type III–IV VBFAs. Conclusions Compared with CM, FD was associated with improved long-term outcomes in unruptured VBFAs, particularly in vertebral artery lesions and Type I–II VBFAs, although residual confounding cannot be excluded.

Background/Aims: Liver transplantation (LT) following total hepatectomy is a life-saving treatment for hepatocellular carcinoma (HCC). The HCC recurrence after LT hinders the effectiveness of the procedure. The objective of this study is to develop a pre-operative risk stratification model based on a liquid biopsy. Methods: We conducted a comprehensive multi-omics study of 260 HCC patients from three centers, including clinical data, low-coverage whole-genome sequencing of cell-free DNA (cfDNA) from plasma, as well as whole-exome, single-nucleus RNA, and spatial transcriptomics from matched tumor and non-tumor tissues. Results: We identified cfDNA-derived copy number alteration (CNA) signatures associated with post-transplant recurrence. By integrating cfDNA-derived CNA profiles with single-cell transcriptomic data, we traced recurrence-associated cfDNA to a distinct subpopulation of malignant cells within the primary tumor. These cells were embedded in a pro-metastatic microenvironment of specialized endothelial subtypes and cancer-associated fibroblasts. Notably, most recurrence-associated lesions were detectable in cfDNA prior to liver transplantation (LT). Building on these insights, we developed the ZJU Criteria based on CNA fragments and tumor markers, a pre-LT risk prediction tool that integrates conventional clinical factors with cfDNA-derived CNA signatures, and validated it using internal and independent external cohorts. Conclusion Our findings suggest that post-transplant recurrence commonly originates from advanced subclones that emerge late during tumor evolution. The ZJU Criteria provides an accurate, non-invasive strategy that significantly improves pre-LT risk stratification and clinical decision-making for patients with HCC.

Objective To analyze the infection status and epidemic trends of soil-borne nematode infections in Yubei, Chongqing City, in 2010,2021, and 2022. Methods The local populations from four survey sites of four towns in 2010 and five sites of five towns in 2021 and 2022 were surveyed regarding their basic information using a unified form. Fecal samples of the participants were collected and tested for soil-borne nematode infections using the modified Kato-Katz thick smear method. Results In 2010, 2 049 participants were surveyed, followed by 1 000 participants in 2021 and 2022. The overall prevalence of parasitic infections declined significantly from 3.86% to 0.20%. In 2010, soil-transmitted nematode included hookworms(3.81%) and roundworms(0.29%). In 2021, the infection rates of roundworms and hookworms were 1.70% and 0.10% respectively. Notably, only Ascaris was identified in 2022(0.20%). The≥60 age group consistently exhibited the highest infection rates across all surveys, followed by the 40-59 age group. The infection rates of males in the three surveys were 3.31%,1.92%, and 0.20% respectively, and those of females were 4.37%, 1.46%, and 0.20% respectively. There was no statistically significant difference in the infection rates between males and females. Educational attainment was inversely associated with infection; in 2010, the highest prevalence was observed among those with primary education or below, whereas in 2021, illiterate or semi-literate individuals showed the highest susceptibility. The occupational distribution of infections in 2010 indicated that retirees (8.33%), farmers(4.86%), and homemakers or unemployed individuals(3.45%)were the most affected. However, in 2021 and 2022, farmers emerged as the predominant occupational group with soil-transmitted nematode infections. Conclusions The infection rate of soil-borne nematodes showed a decreasing trend in Yubei, and the infection species changed from hookworms in 2010 to Ascaris in 2022. Farmers, the elderly, and people with low education levels should continue to be the focus of preventive and control efforts.

Objective We reviewed and analyzed the epidemiological data of 83 imported dengue fever cases reported in Fengtai District, Beijing, from 2007 to 2025, to delineate their epidemiological characteristics and guide the dengue fever prevention and control strategy in the future. Methods Data on dengue fever cases in Fengtai District from 2007 to 2025 were collected to identify the epidemic factors and characteristics using descriptive epidemiological method. Results All 83 dengue fever cases reported in this region over the past two decades have been imported from abroad or other domestic areas, with Southeast Asian countries being identified as the primary source of imported infections, accounting for 42 cases (50.60%), followed by 15 cases (18.07%) from Chinese provinces other than Beijing. The remaining import sources included 13 cases from South Asia,8 from African countries, and each from Oceania, South America, and Europe. Disease onset was found concentrated between May and November. The sex ratio (male-to-female) is 1.59:1. The age of onset ranged from 14 to 61 years old, with a median age of 36. The largest proportion of cases was observed among cadres and office workers (31 cases, 37.35%), followed by businessmen (13 cases, 15.67%), and householders or the unemployed (10 cases,12.05%). Travel visit was identified as the primary reason for their exposure history. Conclusions All dengue fever cases reported in Fengtai from 2007 to 2025 were imported, with an increasing trend of imported cases in Beijing originating from other Chinese provinces. It is essential to strengthen health education for foreign travelers and returning residents, enhance clinical diagnosis and treatment training for medical personnel, eliminate mosquito breeding sites, and reduce mosquito density through active patriotic health campaigns.

Objective To analyze the relationship between the visceral adiposity index(VAI)and nocturia in the US adult population.Methods A cross-sectional study was performed.Data from subjects aged≥20 years in the National Health and Nutrition Examination Survey(NHANES)database from 2007 to 2020 were collected,including waist circumference,triglyceride,body mass index(BMI),high-density lipoprotein,age,gender,race,poverty income ratio,education level,marital status,smoking,alcohol consumption,sleep disorders,depression,occupation,hypertension,diabetes,congestive heart failure,cancer,and nocturnal urination frequency.Weighted analysis,multivariate logistic regression,generalized additive model(GAM),and curve fitting were employed to evaluate the association between VAI and nocturia,adjusting for age,gender,race,poverty income ratio,education level,marital status,smoking,alcohol consumption,sleep disorders,depression,occupation,hypertension,diabetes,congestive heart failure,and cancer.Subgroup analyses were conducted based on age,gender,race,hypertension and diabetes to further evaluate the relationship between VAI and the risk of nocturia.Results A total of 29,196 American adults were included.All subjects were divided into 4 groups based on VAI quartiles:Q1 group(0.32≤VAI<1.01),Q2 group(1.01≤VAI<1.70),Q3 group(1.70≤VAI<2.95),and Q4 group(2.95≤VAI<13.59),with nocturia prevalence rates of 28.5%,31.4%,33.3%,and 34.9%,respectively.In subgroup analyses,the risk of nocturia significantly increased with higher VAI in the 20-40 age group,females and other Hispanics(OR=1.04,95%CI 1.01-1.08,P=0.006;OR=1.02,95%CI 1.00-1.04,P=0.035;OR=1.05,95%CI 1.01-1.09,P=0.026).GAM analysis results showed a nonlinear relationship between VAI and nocturia.Conclusion VAI is positively associated with the risk of nocturia,and may be an effective indicator for predicting the risk of nocturia occurrence.

Objective To analyze the relationship between frailty and acute kidney injury(AKI)after hip fracture surgery in the elderly.Methods A total of 405 elderly patients who underwent hip fracture surgery in Jieyang People's Hospital from August 2021 to January 2023 were retrospectively analysed.According to the modified frailty index(mFI),they were divided into frail group(mFI≥0.27,n=112)and non-frail group(mFI<0.27,n=293).Postoperative AKI was defined according to the Kidney Disease:Improving Global Outcomes(KDIGO)criteria.After 1:1 propensity score matching(PSM),100 cases in each group were successfully matched.Univariable and multivariable logistic regression models,propensity score adjustment,PSM,inverse probability of treatment weighting(IPTW),standardized mortality ratio weighting(SMRW),pairwise algorithm(PA)weighting,and overlap weighting(OW)methods were used to analyze the relationship between frailty and postoperative AKI.Stratified analyses were performed according to age(≥80 or<80 years),gender,whether angiotensin-converting enzyme inhibitors(ACEI)/angiotensin Ⅱreceptor antagonists(ARB)were used,and whether intraoperative hypotension occurred.Results After PSM,there were no significant differences between the two groups in age,sex,surgical type,ACEI/ARB,blood urea nitrogen,serum creatinine,intraoperative blood loss,and intraoperative hypotension[standardized mean difference(SMD)<0.1].In both the original cohort and the matched cohort,the incidence of AKI was higher in frail group than in non-frail group(25.9%vs.8.9%,P<0.001;28.0%vs.11.0%,P=0.002).Analysis of the risk of postoperative AKI in elderly hip fracture patients in frail group found that compared with the non-frail group,in the univariate logistic regression model the odds ratio(OR)and a 95%confidence interval(CI)for the frail group was 3.59(2.00-6.43),P<0.001,and in the multivariable logistic regression model,the OR(95%CI)for frail group was 3.04(1.55-5.95),P=0.001.After adjustment for propensity score,the OR(95%CI)for frail group was 2.85(1.52-5.34),P=0.001,and the OR(95%CI)for frail group after PSM was 3.15(1.47-6.75),P=0.003.After IPTW,SMRW,PA weighting,and OW,the OR(95%CI)for frail group were 2.48(1.37-4.50),2.43(1.41-4.19),2.63(1.25-5.54),and 2.69(1.07-6.78),respectively,with P<0.05.The interaction tests were not statistically significant for age,sex,use of ACEI/ARB,and intraoperative hypotension(P>0.05).Conclusion In elderly patients with hip fractures,preoperative frailty may be a risk factor for postoperative AKI.

Objective To explore the clinical and genetic characteristics of children with holocarboxylase synthetase(HLCS)deficiency.Methods A retrospective analysis was conducted on the clinical data of 3 children with HLCS deficiency who were admitted to Children's Hospital Affiliated to Zhengzhou University from December 2014 to January 2024.Relevant literature indexed in CNKI,Wanfang Data,PubMed and other databases was reviewed to summarize the clinical characteristics and HLCS gene mutations of children with HLCS deficiency.Results All 3 children were male,with onset age of 4-6 months.The main clinical manifestations included shortness of breath,vomiting,diarrhea,and poor mental state,and partial cases were complicated by growth retardation and neurological symptoms.Laboratory tests showed metabolic acidosis in all cases,blood amino acid and acylcarnitine profiles as well as urinary organic acid analysis suggested multiple carboxylase deficiency.Genetic testing revealed compound heterozygous mutation in the HLCS gene of all 3 children,among which the c.1892delT(p.L631X)mutation was previously unreported.According to the guidelines of the American College of Medical Genetics and Genomics(ACMG),the c.1892delT(p.L631X)mutation was rated as pathogenic mutation(PVS1+PM2_supporting+PM3).Biotin supplementation was effective in all cases.Literature review included 27 English literatures and 29 Chinese literatures,reporting a total of 133 children with HLCS deficiency caused by HLCS gene mutation.Common clinical manifestations included metabolic acidosis,skin lesions,vomiting,feeding difficulties,dyspnea,diarrhea,and neurological symptoms,etc.Conclusions Blood amino acid and acylcarnitine profiles,urine organic acid analysis,and gene testing are helpful for the diagnosis of HLCS deficiency.Timely biotin supplementation leads to a good prognosis.The mutation of HLCS gene is considered as the genetic etiology of HLCS deficiency in 3 children,among which the c.1892delT(p.L631X)mutation is a newly discovered mutation.