Clinical characteristics and genetic analysis of a child with Galactosemia due to compound heterozygous variants of GALT gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic basis of a child with Galactosemia.@*METHODS@#A child who had presented at the Children's Hospital Affiliated to Zhengzhou University on November 20, 2019 was selected as the study subject. Clinical data of the child was collected. Whole exome sequencing was carried out for the child. Candidate variants were validated by Sanger sequencing.@*RESULTS@#Clinical manifestations of the child have included anemia, feeding difficulty, jaundice, hypomyotonia, abnormal liver function and coagulation abnormality. Tandem mass spectrometry showed increased citrulline, methionine, ornithine and tyrosine. Urine organic acid analysis showed increased phenyllactic acid, 4-hydroxyphenylacetic acid, 4-hydroxyphenyllactic acid, 4-hydroxyphenylpyruvate and N-acetyltyrosine. Genetic testing revealed that the child has harbored compound heterozygous variants of the GALT gene, namely c.627T>A (p.Y209*) and c.370G>C (p.G124R), which were respectively inherited from her healthy parents. Among these, c.627T>A (p.Y209*) was known as a likely pathogenic variant, while c.370G>C (p. G124R) was unreported previously and also predicted as a likely pathogenic variant(PM1+PM2_Supporting+PP3_Moderate+PPR).@*CONCLUSION@#Above discovery has expanded the spectrum of the GALT gene variants underlying Galactosemia. Patients with thrombocytopenia, feeding difficulties, jaundice, abnormal liver function and coagulation abnormality without obvious causes should be analyzed by screening of metabolic diseases in combination with genetic testing.

Analysis of clinical characteristics and ACADM gene variants in four children with Medium chain acyl-CoA dehydrogenase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of four patients with medium-chain acyl-CoA dehydrogenase deficiency (MCADD).@*METHODS@#Four children who had presented at the Children's Hospital Affiliated to Zhengzhou University between August 2019 and August 2021 were selected as the study subjects. Clinical data of the children were collected. The children were subjected to whole exome sequencing (WES).@*RESULTS@#All of the four children were diagnosed with MCADD. Blood amino acid and ester acyl carnitine spectrum test showed that the concentration of octanoyl carnitine (C8) was significantly increased. The main clinical manifestations included poor mental response (3 cases), intermittent diarrhea with abdominal pain (1 case), vomiting (1 case), increased transaminase (3 cases), and metabolic acidosis (2 cases). Five variants were identified by genetic testing, among which c.341A>G (p.Y114C) was unreported previously. Three were missense variants, one was frameshift variant and one was splicing variant.@*CONCLUSION@#The clinical heterogeneity of MCADD is obvious, and the severity of the disease may vary. WES can assist with the diagnosis. Delineation of the clinical symptoms and genetic characteristics of the disease can facilitate early diagnosis and treatment of the disease.

Clinical and genetic analysis of five children with Catecholaminergic polymorphic ventricular tachycardia due to variants of RYR2 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and genetic characteristics of five children with Catecholaminergic polymorphic ventricular tachycardia (CPVT).@*METHODS@#Five children with clinical manifestations consistent with CPVT admitted to the Department of Cardiology of Children's Hospital Affiliated to Zhengzhou University from November 2019 to November 2021 were selected as the study subjects. Their clinical data were collected. Potential variants were detected by whole exome sequencing, and Sanger sequencing was used to verify the candidate variants. All patients were treated with β-blocker propranolol and followed up.@*RESULTS@#All patients had developed the disease during exercise and presented with syncope as the initial clinical manifestation. Electrocardiogram showed sinus bradycardia. The first onset age of the 5 patients were (10.4 ± 2.19) years, and the time of delayed diagnosis was (1.6 ± 2.19) years. All of the children were found to harbor de novo heterozygous missense variants of the RYR2 gene, including c.6916G>A (p.V2306I), c.527G>C (p.R176P), c.12271G>A (p.A4091T), c.506G>T (p.R169L) and c.6817G>A (p.G2273R). Among these, c.527G>C (p.R176P) and c.6817G>A (p.G2273R) were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.527G>C (p.R176P) was classified as a pathogenic variant (PS2+PM1+PM2_Supporting+PM5+PP3+PP4), and the c.6817G>A (p.G2273R) was classified as a likely pathogenic variant (PS2+PM2_Supporting+PP3+PP4). The symptoms of all children were significantly improved with the propranolol treatment, and none has developed syncope during the follow up.@*CONCLUSION@#Discovery of the c.527G>C (p.R176P) and c.6817G>A (p.G2273R) variants has expanded the mutational spectrum of the RYR2 gene. Genetic testing of CPVT patients can clarify the cause of the disease and provide a reference for their genetic counseling.

Childhood onset spinocerebellar ataxia type 2: a family report and literature review / 中华神经科杂志

Objective:To investigate the clinical characteristics, genetic characteristics and diagnosis of spinocerebellar ataxia type 2 (SCA2) patients with childhood onset.Methods:The clinical data of a SCA2 pedigree who diagnosed at Neurogenetic Metabolic Disease Clinic of Children′s Hospital Affiliated to Zhengzhou University in July 2019 were collected, and the reported cases of childhood-onset SCA2 were reviewed. The CAG repeat of ATXN2 gene was detected by polymerase chain reaction, capillary gel electrophoresis and Sanger sequencing techniques.Results:A total of 9 people in 4 generations of the family were affected, showing an autosomal dominant inheritance. The proband was a 3 years and 4 months old boy, who showed abnormal symptoms at 9 months which manifested as developmental retardation. At 1 year old, he developed progressive regression which represented neither to be amused, recognize others, stand and walk alone, nor had language development. Meanwhile, he had difficulty swallowing, long-term constipation, and a history of convulsions. His sister and mother were not yet sick. His grandmother could not walk, had slurred speech accompanied by nystagmus, and magnetic resonance imaging showed cerebellar atrophy. His granduncles and grandaunts had unstable walking and dysarthria. His great-grandfather required wheelchair to walk. This pedigree showed an autosomal dominant inheritance. One of the ATXN2 gene alleles of the proband, his sister, mother and grandmother all showed abnormal amplification with 99, 55, 44, and 43 times respectively and no inserting CAA sequence. A total of 14 literatures reported 20 cases of childhood-onset SCA2 patients who were genetically diagnosed. The majorities had onset in infancy, and few can develop into school age. The main clinical manifestations were developmental delay, dystonia or insufficiency, myoclonus or infantile spasms, motor retardation, abnormal eye movement, retinitis pigmentosa and dysphagia, while the classic cerebellar syndrome was only partially present. Abnormal rhythm was found on electroencephalogram, cerebellar atrophy on magnetic resonance imaging or CT of the head.Conclusions:This case is the youngest genetically-confirmed SCA2 patient reported in China. Reported patients usually have onset in infancy with excessive repeat sequence expansion. Their clinical characteristics are different from the classic patients and could only be diagnosed by dynamic mutation detection.

3-Hydroxy-isobutyryl-coenzyme A hydrolase deficiency: a case report and literature review / 中华神经科杂志

Objective:To analyze the characteristics of clinical manifestation, auxiliary examination and gene mutation of 3-hydroxy-isobutyryl-coenzyme A hydrolase (HIBCH) deficiency to better understand this disease.Methods:The clinical manifestations and genetic results of a patient with HIBCH deficiency were analyzed. The clinical features and genetic characteristics of HIBCH deficiency were summarized based on the literature review.Results:The proband, female, one year and four months old, was admitted to Children′s Hospital Affiliated to Zhengzhou University for “vomiting and diarrhea for 15 days, dyspnea and intermittent convulsions for 13 days after digestive tract infection”. The intelligence was normal, however, the motor development was slightly delayed before onset. Physical examination showed light coma, poor response and insensitivity to light. She also had shortness of breath, weak positive three concave signs and coarse breath sound in both lungs with sputum purrs. In addition, the muscle tension of extremities was increased. Bilateral Brudzinski′s sign, Babinski′s sign and Kernig′s sign were negative. Serum hydroxybutyryl carnitine (C4OH) was increased. Cranial magnetic resonance imaging (MRI) showed atrophy in bilateral cerebral hemispheres and abnormal symmetry signals in bilateral globus pallidus and cerebral peduncle. Novel compound heterozygous variants of HIBCH, c.489T>A (p. C163*) and c.740A>G (p. Y247C), were found in the patient, which respectively inherited from her healthy parents. Her symptoms were relieved after“cocktail”therapy and symptomatic treatment. Literature related to HIBCH deficiency published all around the world was reviewed. As a result, 17 articles, including 24 cases, had been reported. The majority of patients presented with poor feeding, dystonia and progressive motor developmental delay in early infancy. Cranial MRI showed lesions in bilateral basal ganglia. Serum C4OH concentration was elevated. And compound heterozygous or homozygous variants of HIBCH gene were found in patients with HIBCH deficiency.Conclusions:The detection of serum amino acids and acylcarnitine profiles on HIBCH deficiency was relatively specific and it was helpful to make a clear diagnosis by combining with cranial MRI and genetic tests. In this study, a case of HIBCH deficiency was confirmed, which expanded the mutation spectrum of HIBCH gene. Meanwhile, summarizing the clinical and genetic characteristics of cases reported improved understanding of HIBCH deficiency.

Analysis of MCCC2 gene variant in a pedigree affected with 3-methylcrotonyl coenzyme A carboxylase deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with clinically suspected 3-methylcrotonyl-coenzyme A carboxylase deficiency (MCCD).@*METHODS@#Genomic DNA was extracted from peripheral blood samples of the proband and her parents. Whole exome sequencing was used to screen pathogenic variant in the proband. Suspected variant was verified by Sanger sequencing. Impact of the variant on the structure and function of protein product was analyzed by using bioinformatic software.@*RESULTS@#Sanger sequencing showed that the proband has carried homozygous missense c.1342G>A (p.Gly448Ala) variant of the MCCC2 gene, for which her mother was a heterozygous carrier. The same variant was not detected in her father. The variant was predicted to be pathogenic by PolyPhen-2 and Mutation Taster software, and the site was highly conserved among various species. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.1342G>A (p.Gly448Ala) variant of MCCC2 gene was predicted to be likely pathogenic(PM2+PP2-PP5).@*CONCLUSION@#The homozygous missense variant of the MCCC2 gene c.1342G>A (p.Gly448Ala) probably underlay the molecular pathogenesis of the proband. Genetic testing has confirmed the clinical diagnosis.

A significant increase of RNAi efficiency in human cells by the CMV enhancer with a tRNAlys promoter.

RNA interference (RNAi) is the process of mRNA degradation induced by double-stranded RNA in a sequence-specific manner. Different types of promoters, such as U6, H1, tRNA, and CMV, have been used to control the inhibitory effect of RNAi expression vectors. In the present study, we constructed two shRNA expression vectors, respectively, controlled by tRNA(lys) and CMV enhancer-tRNA(lys) promoters. Compared to the vectors with tRNA(lys) or U6 promoter, the vector with a CMV enhancer-tRNA(lys) promoter silenced pokemon more efficiently on both the mRNA and the protein levels. Meanwhile, the silencing of pokemon inhibited the proliferation of MCF7 cells, but the induction of apoptosis of MCF7 cells was not observed. We conclude that the CMV enhancer-tRNA(lys) promoter may be a powerful tool in driving intracellular expression of shRNA which can efficiently silence targeted gene.

Fast and Almost 100% Efficiency Site-directed Mutagenesis by The Megaprimer PCR Method / 生物化学与生物物理进展

A novel PCR-based mutagenesis method was reported, in which there is no need to purify megaprimers or design a special flanking primer. This method used one mutagenic primer and two sequencing primers (T_m≤58℃) as flanking primers. After first round PCR, 12.5 μl first PCR production was directly added into 50 μl second PCR system as template and megaprimer, and 10 rounds of asymmetrical PCR at high temperature of annealing (68 ℃ ) was to add in initiation of second PCR. This additional step greatly has increased the efficiency of mutagenesis via 600 bp or 800 bp long megaprimer. The results demonstrated that this method can achieve high fidelity, 97%～ 98% efficiency, high yield.

The Cross-section Study on the Obesity and Hypertension in Children Aged 6 to 12 yrs,in Shenzhen / 中国慢性病预防与控制

Objective To investigate the prevalence of hypertension and obesity and their main influencial factors among 6～12 years old children in Shenzhen.Method 1 140 children aged from 6 to 12 years old in 4 schools in Shenzhen were sampled by random cluster sampling,and their systolic blood pressure(SBP),diastolic blood pressure(DBP),body height,weight and other morphological parameters were measured.Results The prevalent rate of hypertension was 9.4%(8.6% for boys and 10.2% for girls);Rate of overweight and obesity for boys were 13.25% and 13.72,respectively,and the girl were 9.09% and 8.10%,respectively.There were a increasing trend toward SBP and DBP with age,especially SBP.After adjusted with age and gender,the partial correlation coefficients between BMI and SBP,DBP were 0.462 and 0.357,respectively(P

Construction of thioredoxin-DsRed and APE/ref-1-EGFP fusion protein vectors and their localization in 293T cells / 基础医学与临床

Objective To construct thioredoxin and APE/ref-1 fusion protein expression vector and to investigate their subcellular localization of the fusion proteins in 293Tcells.Methods The APE/ref-1 cDNA was cloned by RT-PCR from PC12 cell.APE/ref-1-EGFP fusion protein expression vector was constructed through subcloning.Thioredoxin cDNA was subcloned into pDSred1-1 from pQE30-TRX plasmid by PCR,and thioredoxin-DsRed fusion protein expression vector was constructed in pCMV5 plasmid.The expression and subcellular localization of the fusion proteins in 293T cells transfected with the vectors by calcium phosphate was analyzed by fluorescent microscopy.Results The results demonstrated that thioredoxin——DsRed and APE/ref-1-EGFP fusion protein expression vectors were successfully constructed and expressed in 293T cells.APE/ref-1-EGFP fusion protein was located only in nucleus,and thioredoxin-DsRed fusion protein was located in cytoplasm as well as nucleus.ConclusionThis study has set up a solid base for further to study on the dynamic interaction between thioredoxin and APE/ref-1 fusion proteins.