The design of high affinity human PD-1 mutants by using molecular dynamics simulations (MD).

BACKGROUND: Programmed cell death protein 1 (PD-1), a negative co-stimulatory molecule, plays crucial roles in immune escape. Blockade of the interaction between PD-1 and PD-L1 shows exciting clinical responses in a fraction of cancer patients and the success makes PD-1 as a valuable target in immune checkpoint therapy. For the rational design of PD-1 targeting modulators, the ligand binding mechanism of PD-1 should be well understood in prior. METHODS: In this study, we applied 50 ns molecular dynamics simulations to observe the structural properties of PD-1 molecule in both apo and ligand bound states, and we studied the structural features of PD-1 in human and mouse respectively. RESULTS: The results showed that the apo hPD-1 was more flexible than that in PD-L1 bound state. We unexpectedly found that K135 was important for binding energy although it was not at the binding interface. Moreover, the residues which stabilized the interactions with PD-L1 were distinguished. Taking the dynamic features of these residues into account, we identified several residual sites where mutations may gain the function of ligand binding. The in vitro binding experiments revealed the mutants M70I, S87 W, A129L, A132L, and K135 M were better in ligand binding than the wild type PD-1. CONCLUSIONS: The structural information from MD simulation combined with in silico mutagenesis provides guidance to design engineered PD-1 mutants to modulate the PD-1/PD-L1 pathway.

Silicon nanoparticles coated with an epitope-imprinted polymer for fluorometric determination of cytochrome c.

The authors describe a composite consisting of silicon nanoparticles that were first coated with SiO2 and then with a molecularly imprinted polymer (SiNP@SiO2@MIP). The MIP was generated by dual epitope imprinting such that it can recognize cytochrome c (Cyt c). The MIP on the NPs was prepared from the functional monomer zinc(II) acrylate (ZnA), the crosslinker ethylene glycol dimethacrylate and the initiator 2,2'-azoisobutyronitrile. Dual epitope templates for Cyt c included (a) a C-terminal nonapeptide (AYLKKATNE), and (b) an N-terminal nonapeptide (GDVEKGKKI). The chelation between Zn(II) of ZnA and the amino groups or hydroxy groups of the template nonapeptides warrants good recognition and capture of Cyt c. The fluorescence originating from SiNPs has excitation/emission peaks at 360/480 nm and is quenched by Cyt c in the 0.50-40.0 µM concentration range. The correlation coefficient for the calibration plot of the imprinted NPs is 0.9937. The detection limit is 0.32 ± 0.01 µM, the precisions of six replicate detections at levels of 0.5, 20 and 40 µM Cyt c are 3.2, 2.7 and 2.8%, respectively, and the imprinting factor is 2.43. Compared to single epitope template imprinting, dual epitope imprinting results in improved selectivity. The imprinted nanoparticles can discriminate Cyt c even if one amino acid is mismatched. The method was applied to the determination of Cyt c in spiked diluted human serum and gave recoveries between 94.0 and 107.5%. Graphical Abstract A fluorescent material of the architecture silicon nanoparticle@SiO2@molecularly imprinted polymer (SiNP@SiO2@MIP) was fabricated by dual epitope imprinting and a metal-chelating method. The chelation between Zn(II) of the functional monomer zinc(II) acrylate and the amino groups or hydroxy groups of template warrants that the material recognizes and captures cytochrome c well, and this results in fluorescence quenching.

Sequence control of phase separation and dewetting in PS/PVME blend thin films by changing molecular weight of PS.

The morphology evolution mechanism of polystyrene (PS)/poly (vinyl methyl ether) (PVME) blend thin films with different PS molecular weights (Mw) was studied. It was found that the morphology evolution was closely related to the molecular weight asymmetry between PS and PVME. In the film where Mw(PS) ≈ Mw(PVME), dewetting happened at the interface between the bottom layer and substrate after SD phase separation. While in the film where Mw(PS) >> Mw(PVME), dewetting happened at the interface between the middle PS/PVME blend layer and bottom PVME layer near the substrate prior to phase separation. The different sequences of phase separation and dewetting and different interface for dewetting occurrence were studied by regarding the competitive effects of viscoelasticity contrast between polymer components and preferential wetting between PVME and the substrate. The viscoelastic nature of the PS component played a crucial role in the sequence of phase separation and dewetting.

[Psychomotor retardation and intermitent convulsions for 8 months in an infant].

This study reports a boy with psychomotor retardation and epilepsy due to maternal phenylketonuria (PKU). The boy was admitted at the age of 20 months because of psychomotor retardation and epilepsy. He had seizures from the age of 1 year. His development quotient was 43. He presented with microcephaly, normal skin and hair color. Brain MRI scan showed mild cerebral white matter demyelination, broadening bilateral lateral ventricle and foramen magnum stricture. Chromosome karyotype, urine organic acids, blood amino acids and acylcarnitines were normal. His mother had mental retardation from her childhood. She presented with learning difficulties and yellow hair. Her premarriage health examinations were normal. She married a healthy man at age of 26 years. When she visited us at 28 years old, PKU was found by markedly elevated blood phenylalanine (916.54 µmol/L vs normal range 20-120 µmol/L). On her phenylalanine hydroxylase (PAH) gene, a homozygous mutations c.611A>G (p.Y204C) was identified, which confirmed the diagnosis of PAH-deficient PKU. Her child carries a heterozygous mutation c.611A>G with normal blood phenylalanine. Her husband had no any mutation on PAH. It is concluded that family investigation is very important for the etiological diagnosis of the children with mental retardation and epilepsy. Carefully clinical and metabolic survey should be performed for the parents with mental problems to identify parental diseases-associated child brain damage, such as maternal PKU.

Efficacy of kidney-tonifying traditional Chinese medicine prescriptions in hypoplastic uterus treatment: a systematic review and meta-analysis.

AIM: To review and evaluate the efficacy of kidney-tonifying traditional Chinese medicine prescriptions (KT-TCMP) in hypoplastic uterus (HU) treatment. METHODS: We searched MEDLINE, the Cochrane Library, CNKI (China National Knowledge Infrastructure), WANFANG and VIP databases until 14 December 2013 independently with two investigators. Randomized controlled trials (RCT) involving KT-TCMP as a combined or monotherapy in the treatment of HU were reviewed and analyzed. Meta-analysis was performed by Review Manager (version 5.2). RESULTS: Nine RCT of 1745 patients were eligible for this review and meta-analysis, of which eight RCT described the primary outcome of clinical efficacy and three RCT drew the secondary outcome of uterine size. Meta-analyzed 'recovery' clinical efficacy of KT-TCMP in seven RCT was conducted which considered diethylstilbestrol therapy alone as control, as well as three RCT that meta-analyzed the effect of KT-TCMP on uterine diameter enlargement. As a result, KT-TCMP therapy had a significantly improved difference in increasing 'recovery' clinical efficacy (risk ratio, 2.34; 95% confidence interval [CI], 1.90-2.89) and enlarging the uterine diameter (standardized mean difference, 1.62; 95% CI, 1.39-1.84). One study reported adverse reactions as an important outcome and found it was safe during KT-TCMP therapy. CONCLUSION: The therapy of applying KT-TCMP as a combined or monotherapy in the treatment of HU may be more efficacious. However, these RCT were of moderate methodological quality and small sample size; thus, the results should be confirmed with more rigorously controlled further studies.

Novel CuMgAlTi-LDH Photocatalyst for Efficient Degradation of Microplastics under Visible Light Irradiation.

Microplastics (MPs) in the water system could easily enter the human body and pose a potential threat, so finding a green and effective solution remains a great challenge. At present, the advanced oxidation technology represented by photocatalysis has been proven to be effective in the removal of organic pollutants, making it a feasible method to solve the problem of MP pollution. In this study, the photocatalytic degradation of typical MP polystyrene (PS) and polyethylene (PE) by a new quaternary layered double hydroxide composite photomaterial CuMgAlTi-R400 was tested under visible light irradiation. After 300 h of visible light irradiation, the average particle size of PS decreased by 54.2% compared with the initial average particle size. The smaller the particle size, the higher the degradation efficiency. The degradation pathway and mechanism of MPs were also studied by GC-MS, which showed that PS and PE produced hydroxyl and carbonyl intermediates in the process of photodegradation. This study demonstrated a green, economical, and effective strategy for the control of MPs in water.

The evolution of SARS-CoV-2 and the COVID-19 pandemic.

Scientists have made great efforts to understand the evolution of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) to provide crucial information to public health experts on strategies to control this viral pathogen. The pandemic of the coronavirus disease that began in 2019, COVID-19, lasted nearly three years, and nearly all countries have set different epidemic prevention policies for this virus. The continuous evolution of SARS-CoV-2 alters its pathogenicity and infectivity in human hosts, thus the policy and treatments have been continually adjusted. Based on our previous study on the dynamics of binding ability prediction between the COVID-19 spike protein and human ACE2, the present study mined over 10 million sequences and epidemiological data of SARS-CoV-2 during 2020-2022 to understand the evolutionary path of SARS-CoV-2. We analyzed and predicted the mutation rates of the whole genome and main proteins of SARS-CoV-2 from different populations to understand the adaptive relationship between humans and COVID-19. Our study identified a correlation of the mutation rates from each protein of SARS-CoV-2 and various human populations. Overall, this analysis provides a scientific basis for developing data-driven strategies to confront human pathogens.

Primary resistance to first- and second-generation ALK inhibitors in a non-small cell lung cancer patient with coexisting ALK rearrangement and an ALK F1174L-cis-S1189C de novo mutation: A case report.

The effectiveness of the tyrosine kinase inhibitor ALK (TKI) for non-small cell lung cancer has been confirmed. However, resistance to ALK-TKIs seems inevitable. Mutations in the ALK kinase domain have been reported as an important mechanism of acquired resistance to ALK therapy. However, patients with de novo ALK kinase domain mutations and ALK rearrangements who were not treated with ALK inhibitors have rarely been reported. Here, we report a case of primary drug resistance to first- and second-generation ALK inhibitors in a NSCLC patient with ALK-rearrangement. The next-generation sequencing test of the pathological biopsy showed that the de novo ALK kinase domain mutation F1174L-cis-S1189C may be the cause of primary drug resistance.

Case Report: A Case Report of a Histological Transformation of ALK-Rearranged Adenocarcinoma With High Expression of PD-L1 to Squamous Cell Carcinoma After Treatment With Alectinib.

We report an anaplastic lymphoma kinase (ALK)-positive patient shows a poor response to the ALK inhibitor alectinib due to the high expression of programmed death-ligand 1 (PD-L1). After treatment with alectinib, the pathological form changed from adenocarcinoma into squamous cell carcinoma without novel genetic changes. This case may reveal a direct relationship between ALK mutation and a high level of PD-L1 expression.

Impact of O3 on the phytoremediation effect of Celosia argentea in decontaminating Cd.

Elevated atmospheric O3 can inhibit the growth rate of various plants and increase metal content in their tissues owing to the oxidative damage, thereby affecting their phytoremediation efficiency. In this study, a series of O3 fumigation treatments were designed to evaluate the dry weight, Cd content, and transpiration rate responses of Celosia argentea to different levels of O3 (40, 50, 55, 60, 65, and 80 ppb). The dry weight of C. argentea decreased as the atmospheric O3 level increased, and the Cd concentration of the plant leaves increased until the level of O3 reached 60 ppb before decreasing slightly. The variations in the transpiration rate followed a similar trend to the Cd content under different O3 levels. The phytoremediation efficiency of C. argentea increased with O3 fumigation at low (50 ppb) and moderate (55 and 60 ppb) levels, and significantly decreased at the highest level. The regression curves indicated that the plant species treated with 52 ppb of O3 exhibited the highest Cd accumulation capacity. Overall, the phytoremediation effect of C. argentea cultivated in Cd-polluted soil might be improved under the high-O3 conditions. This result might help to choose suitable plants for soil remediation in future atmospheric environment.

Missense Variant of Endoplasmic Reticulum Region of WFS1 Gene Causes Autosomal Dominant Hearing Loss without Syndromic Phenotype.

OBJECTIVE: Genetic variants in the WFS1 gene can cause Wolfram syndrome (WS) or autosomal dominant nonsyndromic low-frequency hearing loss (HL). This study is aimed at investigating the molecular basis of HL in an affected Chinese family and the genotype-phenotype correlation of WFS1 variants. METHODS: The clinical phenotype of the five-generation Chinese family was characterized using audiological examinations and pedigree analysis. Target exome sequencing of 129 known deafness genes and bioinformatics analysis were performed among six patients and four normal subjects to screen suspected pathogenic variants. We built a complete WFS1 protein model to assess the potential effects of the variant on protein structure. RESULTS: A novel heterozygous pathogenic variant NM_006005.3 c.2020G>T (p.Gly674Trp) was identified in the WFS1 gene, located in the C-terminal domain of the wolframin protein. We further showed that HL-related WFS1 missense variants were mainly concentrated in the endoplasmic reticulum (ER) domain. In contrast, WS-related missense variants are randomly distributed throughout the protein. CONCLUSIONS: In this family, we identified a novel variant p.Gly674Trp of WFS1 as the primary pathogenic variant causing the low-frequency sensorineural HL, enriching the mutational spectrum of the WFS1 gene.

Dynamics of binding ability prediction between spike protein and human ACE2 reveals the adaptive strategy of SARS-CoV-2 in humans.

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a novel coronavirus causing the COVID-19 pandemic in 2020. High adaptive plasticity on the spike protein of SASR-CoV-2 enables it to transmit across different host species. In the present study, we collected 2092 high-quality genome sequences of SARS-CoV-2 from 160 regions in over 50 countries and reconstructed their phylogeny. We also analyzed the polymorphic interaction between spike protein and human ACE2 (hACE2). Phylogenetic analysis of SARS-CoV-2 suggests that SARS-CoV-2 is probably originated from a recombination event on the spike protein between a bat coronavirus and a pangolin coronavirus that endows it humans infectivity. Compared with other regions in the S gene of SARS-CoV-2, the direct-binding sites of the receptor-binding domain (RBD) is more conserved. We focused on 3,860 amino acid mutations in spike protein RBD (T333-C525) of SARS-CoV-2 and simulated their differential stability and binding affinity to hACE2 (S19-D615). The results indicate no preference for SARS-CoV-2 infectivity on people of different ethnic groups. The variants in the spike protein of SARS-CoV-2 may also be a good indicator demonstrating the transmission route of SARS-CoV-2 from its natural reservoir to human hosts.

Dendritic Cell Targeting Peptide-Based Nanovaccines for Enhanced Cancer Immunotherapy.

Immunotherapy emerges as an effective avenue for tumor elimination and has many advantages compared with traditional surgery, radiotherapy, and chemotherapy. Tumor vaccines play an important role in cancer immunotherapy, while the application of tumor vaccines in clinical usage is limited because only limited response can be induced by primary tumor antigens. Accordingly, it is a key point to activate T-cell response with some novel tumor vaccines. Here, we applied phage display biopanning and screened a peptide (TY) that could combine with bone-marrow-derived-dendritic-cells (BMDCs) specifically and spleenic DCs. Then we developed mesoporous silica nanoparticles (MSN-TY/OVA/CpG), with peptide TY and OVA/CpG to target and activate DCs, respectively. Our results showed that the nanoparticles (NPs) could be specifically absorbed by DC in vitro, which enhanced the maturation and activation of DCs in vitro and in vivo. The in vitro study demonstrated the efficiency of nanoparticles in antigen uptake by BMDCs and in the activation of antigen-specific cytotoxic CD8+ T cells. Moreover, MSN-TY/OVA/CpG could activate antigen-specific CD8+ T cells and elicited the cytotoxic T lymphocyte (CTL) priming in naive C57BL/6J mice. Therapeutic application of MSN-TY/OVA/CpG enhanced the activation of DCs and the introducing of CD8+ T cell-mediated immune response to promote tumor elimination, prolong survival of tumor-bearing mice, and cause less systemic toxicity. All these results showed that the targeted nanovaccines could deliver antigen into DCs and activate cancer immunotherapy.

Thermosensitive Metal Chelation Dual-Template Epitope Imprinting Polymer Using Distillation-Precipitation Polymerization for Simultaneous Recognition of Human Serum Albumin and Transferrin.

A new type of thermosensitive dual-template epitope molecular imprinting polymer was prepared and coated on magnetic carbon nanotubes (MCNTs@D-EMIP) for simultaneous recognition of human serum albumin (HSA) and transferrin (Trf) via the strategies of dual-template epitope imprinting, metal chelation imprinting, and distillation-precipitation polymerization (DPP). C-terminal peptides of HSA and C-terminal peptides of Trf were selected as templates, zinc acrylate and N-isopropylacrylamide were used as functional monomers, and MCNTs@D-EMIP was prepared by the method of DPP. The two types of template epitopes were immobilized by metal chelation and six-membered ring formed with zinc acylate. MCNTs@D-EMIP was prepared in only 30 min, which was much shorter than other polymerization methods. The resultant MCNTs@D-EMIP showed excellent specific recognition ability toward HSA and Trf. The adsorption amounts of MCNTs@D-EMIP for HSA and Trf were 103.67 and 68.48 mg g-1 and the imprinting factors were 2.57 and 2.17, respectively. In addition, MCNTs@D-EMIP displayed a thermosensitive property to realize temperature-controlled recognition and release of target proteins. Furthermore, the results of high-performance liquid chromatography analysis proved that MCNTs@D-EMIP could be applied to specifically recognize two types of targets simultaneously in the biosample. The proposed strategy provided a preparation method for the thermosensitive dual-template epitope imprinting polymer via dual-template imprinting, metal chelation imprinting, and DPP.

Metal chelation dual-template epitope imprinting polymer via distillation-precipitation polymerization for recognition of porcine serum albumin.

A novel dual-template epitope imprinting polymer coated on magnetic carbon nanotubes (MCNTs@D-EMIP) was successfully prepared for specific recognition of porcine serum albumin (PSA) via dual-template epitope imprinting, metal chelation imprinting and distillation-precipitation polymerization (DPP). C-terminal peptides and N-terminal peptides of PSA were selected as templates simultaneously, and zinc acrylate and ethylene glycol dimethacrylate (EGDMA) were used as functional monomer and cross-linker, respectively. The epitope templates were immobilized by metal chelation and six-membered ring formed with zinc acrylate. Finally, MCNTs@D-EMIP was synthesized by DPP in only 30 min, which was much shorter than those of other polymerization methods. The prepared MCNTs@D-EMIP displayed specific recognition ability toward PSA and its adsorption amount and imprinting factor were 45.05 mg g-1 and 4.50, which were much higher than those of single template epitope imprinting polymers. Besides, high-performance liquid chromatography (HPLC) analysis of PSA in porcine blood serum real sample indicated that the specificity was not affected by other competitive proteins, which forcefully stated that the MCNTs@D-EMIP had potential to be applied in bio-separation area. In addition, the results of cross-reactivity experiment proved that this strategy had generality to prepare dual-template epitope imprinting polymer for recognition of target protein. In summary, this study provided an efficient protocol to recognize target protein in complex sample via dual-template epitope imprinting approach, metal chelation imprinting and distillation-precipitation polymerization.

Development of automated online gel permeation chromatography-gas chromatograph mass spectrometry for measuring multiresidual pesticides in agricultural products.

An automated online gel permeation chromatography-gas chromatograph mass spectrometer (GPC-GC/MS) was developed for the rapid determination of residual pesticides in agricultural products. Pesticides were extracted from homogenized food samples with acetonitrile and decontaminated via the matrix solid-phase dispersion (MSPD) technique, using a primary secondary amine as sorbent prior to GPC-GC/MS analysis. A slightly modified preparation method and automated GPC step proved useful in minimizing matrix interference. To evaluate the performance of the system, 97 target pesticides were spiked at a concentration of 0.1mg/kg into a range of food types, including potato, cabbage, carrot, apple, orange, cucumber, and rice. A low flow rate of 0.1 mL/min in GPC resulted in a 40-fold reduction in solvent consumption compared with conventional GPC column applications. The combination of MSPD technique and GPC-GC/MS for the analysis of the 97 pesticides can be accomplished within 90 min. Most pesticides were recovered in the range of 70-120%, with relative standard deviation generally less than 10%. The results demonstrate that the method can be successfully applied with acceptable recoveries to a broad range of target pesticides within a diverse range of food types.

Preparation of High-Efficiency Cytochrome c-Imprinted Polymer on the Surface of Magnetic Carbon Nanotubes by Epitope Approach via Metal Chelation and Six-Membered Ring.

A novel epitope molecularly imprinted polymer on the surface of magnetic carbon nanotubes (MCNTs@EMIP) was successfully fabricated to specifically recognize target protein cytochrome c (Cyt C) with high performance. The peptides sequences corresponding to the surface-exposed C-terminus domains of Cyt C was selected as epitope template molecule, and commercially available zinc acrylate and ethylene glycol dimethacrylate (EGDMA) were employed as functional monomer and cross-linker, respectively, to synthesize MIP via free radical polymerization. The epitope was immobilized via metal chelation and six-membered ring formed between the functional monomer and the hydroxyl and amino groups of the epitope. The resulting MCNTs@EMIP exhibited specific recognition ability toward target Cyt C including more satisfactory imprinting factor (about 11.7) than that of other reported imprinting methods. In addition, the MCNTs@EMIP demonstrated a high adsorption amount (about 780.0 mg g(-1)) and excellent selectivity. Besides, the magnetic property of the support material made the processes easy and highly efficient by assistance of an external magnetic field. High-performance liquid chromatography analysis of Cyt C in bovine blood real sample and protein mixture indicated that the specificity was not affected by other competitive proteins, which forcefully stated that the MCNTs@EMIP had potential to be applied in bioseparation area. In brief, this study provided a new protocol to detect target protein in complex sample via epitope imprinting approach and surface imprinting strategy.

Seven novel mutations of the SMPD1 gene in four Chinese patients with Niemann-Pick disease type A and prenatal diagnosis for four fetuses.

BACKGROUND: Niemann-Pick disease type A (NPD-A) is a rare autosomal recessive lysosomal storage disorder caused by acid sphingomyelinase deficiency. Only a few cases have been documented in mainland China, and prenatal diagnosis has not been performed to date. In this study, the clinical and laboratory features of four Chinese patients with early-onset NPD-A were summarized. METHODS: Four patients with NPD-A were the firstborns of non-consanguineous parents from four unrelated Chinese families. Bone marrow analysis, acid sphingomyelinase assay and genetic studies were performed. SMPD1 gene studies on amniocytes were performed for the prenatal diagnosis of four fetuses from three families. RESULTS: Four patients were admitted at the age of 1-10 months due to jaundice, hepatosplenomegaly and psychomotor retardation. Liver histopathological analysis revealed glucolipid accumulation. Massive foamy histiocytes were found in the bone marrow. Acid sphingomyelinase activities of peripheral blood leukocytes were significantly decreased (4.05-21.9 nmol/h/mg protein, normal range 216.1-950.9 nmol/h/mg protein). Seven novel mutations (c.518-519insT, c.562_563insC, c.792Gdel, c.949G>A, c.1487_1499delACCGTGTGTACCA, c.1495T>C and c.1670T>C) of the SMPD1 gene were identified in four patients. Only one fetus had two mutations of the SMPD1 gene of amniocytes. The results suggested that the fetus was affected by NPD-A. The mother chose artificial abortion. The other three fetuses were not affected by NPD-A. No mutation of the SMPD1 gene was detected in the cultured amniocytes from the mothers. Postnatal genetic analysis and normal development of the three infants confirmed the prenatal diagnosis. CONCLUSIONS: Seven novel mutations associated with NPD-A were identified in the Chinese population. Prenatal diagnosis for four fetuses of three families was successfully performed by amniocyte gene analysis.

The first Chinese case report of hereditary folate malabsorption with a novel mutation on SLC46A1.

BACKGROUND: Hereditary folate malabsorption is a rare, autosomal recessive disorder of proton-coupled folate transporter deficiency resulting in folate deficiency. Left untreated, the condition can cause severe brain damage and megaloblastic anemia, leading to progressive psychomotor retardation, seizures and other neurological problems. Early diagnosis and treatment are crucial. No case has been documented yet in Mainland China until now. METHODS: A Chinese girl affected by hereditary folate malabsorption was studied. The girl presented with recurrent megaloblastic anemia from the age of 7 months. Paroxysmal limbs trembling and seizures were presented from the age of three years. Intracranial calcification was noted by CT. At her age of 5 years, mental regression, lower-extremity weakness and sleeping problems were observed. Her plasma folate decreased to 4.49 nmol/L (normal control>6.8nmol/L). Plasma total homocysteine elevated to 28.11 µmol/L (normal control<15 µmol/L). Folate and 5-methylterahydrofolate in cerebrospinal fluid were significantly decreased to undetectable level. RESULTS: On SLC46A1 gene, a novel mutation, c.1A>T (M1L), and a reported mutation c.194-195 insG (p.Cys66LeufsX99) were identified, supported the diagnosis of hereditary folate malabsorption. Each parent carries one of two mutations. Folinic calcium supplement resulted in rapid clinical improvement. She is currently 6 years old with normal development and routine blood features. CONCLUSION: Hereditary folate malabsorption is one of the few easily-treatable inherited metabolic diseases. Measurements of folate and 5-methyltetrahydrofolate in cerebrospinal fluid are keys for the diagnosis of the patients.

[Seven patients of argininemia with spastic tetraplegia as the first and major symptom and prenatal diagnosis of two fetuses with high risk].

OBJECTIVE: Argininemia is a rare disorder of urea cycle defect. The clinical manifestations of this disorder are similar to those of cerebral palsy so that the diagnosis is usually much delayed. This study aimed to investigate the phenotypes and genotypes of seven Chinese patients suffering from argininemia. METHOD: Three boys and four girls with spastic tetraplegia were diagnosed as argininemia by blood aminoacids analysis and ARG1 gene study. Patients were given a protein-restricted diet, citrulline, sodium benzoate, and other treatment intervention. The mother of Patient 5 and 6 accepted genetic counseling and underwent prenatal diagnosis by amniocentesis. RESULT: Seven patients presented with progressive spastic tetraplegia and poor physical growth from the age of 1 month to 4 years. Argininemia was found at the age of 1 year and 10 months to 12 years. Five patients had mental retardations. Three had seizures. Their blood arginine elevated (86.66 to 349.83 µmol/L, normal controls 5 to 25 µmol/L). Liver dysfunction was found in six patients. Five patients had elevated blood ammonia levels. In four patients, cerebral atrophy was observed by cranial magnetic resonance imaging. Nine mutations in the ARG1 gene were identified from 7 patients. Only two mutations, c.703G > A in exon 7 and c.32T > C in exon 1 had been reported. c.34G > T, c.53G > A, c.67delG, c.232dupG, c.374C > T, c.539G > C and c.646-649delCTCA, were novel mutations of ARG1. A homozygous mutation c.703G > A was found in the amniocytes of Patient 5's mother, indicating that the fetus was affected by argininemia. Induced abortion was performed. c.53G > A from Patient 6 was not found in the amniocytes of her mother, indicating that the fetus was not affected by hepatocyte arginase deficiency. The result was confirmed by postnatal mutation analysis of cord blood and the normal blood arginine of the newborn. CONCLUSION: Argininemia is one of the few treatable causes of pediatric spastic paralysis. In this study, seven Chinese patients with spastic tetraplegia were detected by blood aminoacids analysis and confirmed by molecular analysis. Seven novel mutations on ARG1 gene were identified. Prenatal diagnosis of the fetus of a family was performed by amniocytes ARG1 gene analysis.