MicroRNA (miRNA) is a non-coding single-stranded RNA with a length of approximately 22 nucleotides and is mainly responsible for the regulation of gene expression at the post-transcriptional level. At present, miRNA have become potential biomarkers for various diseases such as tumor, leukemia, and nervous system disease. Muscle-specific microRNAs are enriched in the skeletal muscle of patients with Duchenne muscular dystrophy (DMD) and also play an important role in the pathogenesis of DMD. Creatine kinase has limited specificity in the diagnosis of DMD since its level is not significantly associated with disease severity, and therefore, it is of great clinical significance to explore whether muscle-specific microRNAs can be used as ideal biomarkers for DMD. This article reviews the research advances in this field.
Biomarkers ; Creatine Kinase ; Humans ; MicroRNAs ; Muscle, Skeletal ; Muscular Dystrophy, Duchenne ; genetics

OBJECTIVE: To explore the genetic basis for a child affected with cerebral creatine deficiency syndrome 1 (CCDS1). METHODS: High-throughput sequencing was carried out to screen pathogenic variant associated with the clinical phenotype of the proband. The candidate variant was verified by Sanger sequencing. RESULTS: High-throughput sequencing revealed that the proband has carried heterozygous c.327delG variant of the SLC6A8 gene, which was verified by Sanger sequencing.Neither parent was found to carry the same variant. CONCLUSION The de novo heterozygous c.327delG variant of the SLC6A8 gene probably underlay the CCDS1 in this child.
Brain Diseases, Metabolic, Inborn/genetics* ; Creatine ; Genetic Testing ; Heterozygote ; Humans ; Mental Retardation, X-Linked ; Mutation

BACKGROUNDRetroviral vectors have been widely used to introduce foreign into various target cells in vitro, thus showing relatively high systemic delivery efficiency of various transgene products. The authors investigated the stability and efficiency of skeletal muscle-specific hybrid retroviral vectors in expression of human factor IX (FIX) in vitro and iv vivo.

METHODSFIX cDNA in LIXSN vector was replaced with a FIX minigene containing splicing donor and splicing acceptor sequence of first intron of human FIX gene. Two copies of muscle creatine kinase enhancer (MCK, Me2) were inserted in forward or reverse orientation at NheI site of 3' long terminal repeat (LTR), resulting in two hybrid vectors, which were designated as LMe2IXm2SN(F) and LMe2IXm2SN(R), respectively. The vectors were tested in vitro and in vivo for stability and muscle-specificity of factor IX expression with SCID mice.

RESULTSMuscle cells carrying vector with Me2 expressed significantly higher levels of FIX (up to 1800 ng/106.24 h) than those without Me2, thus suggesting that Me2 could specifically increase expression level of FIX in muscle cells. Myoblasts transduced with LMe2IXm2SN(R) produced much less FIX in vivo in SCID mice than LMe2IXm2SN(F). One or two copies of Me2 sequence were deleted in myoblasts transduced with LMe2IXm2SN(R) without changing the orientation of Me2.

CONCLUSIONSLTR inserted with MCK enhancers can specifically increase human FIX expression in skeletal muscle cells in vitro and in vivo, and MCK enhancer should be positioned in the same orientation as that of LTR promoter.

Animals ; Creatine Kinase ; genetics ; Creatine Kinase, MM Form ; Enhancer Elements, Genetic ; Factor IX ; analysis ; genetics ; Gene Expression ; physiology ; Genetic Techniques ; Genetic Vectors ; Hybridization, Genetic ; Isoenzymes ; genetics ; Mice ; Mice, SCID ; Retroviridae ; genetics ; Terminal Repeat Sequences

OBJECTIVETo investigate the feasibility of monitoring therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on a rabbit VX2 liver tumor model by using phosphorous-31 magnetic resonance spectroscopy (31P MRS).

METHODSA total of 18 healthy New Zealand White rabbits were used to generate animal models by implanting VX2 tumor chips into livers through laparotomy. Tumor-bearing animals were randomly divided into three groups and were injected with AdCMVIL12-IRES-CKb, AdCMV-Empty and saline respectively via ear veins. 31P MRS scan was performed after animals were fed with creatine solution for five days. Animals were euthanized thereafter and tumors were removed for pathological examination, immunohistochemistry (IHC) staining and protein analysis (Western blot).

RESULTSThe intrahepatic and seral expressions of creatine kinase (CKb) and IL-12 were detected only in AdCMVIL12-IRES-CKb group. Tumor diameters pre- and post- treatment in three groups were 1.63+/-0.04 vs 1.62+/-0.03 in AdCMVIL12-IRES-CKb group (P = 0.229), 1.59+/-0.05 vs 1.84+/-0.11 in AdCMV-Empty group (P = 0.003) and 1.60+/-0.02 vs 2.07+/-0.12 in saline group (P = 0.001), respectively. Pcr Changes between pre- and post- treatment among the three groups were compared (F = 6.235, P value is less than 0.05). PCr increased significantly in AdCMVIL12-IRES-CKb group as compared to AdCMV-Empty (P = 0.004) and saline group (P = 0.049), whereas no change found between AdCMV-Empty and saline group (P = 0.153).

CONCLUSION31P MRS, an effective and non-invasive functional imaging method, can be used to monitor the therapeutic effect of adenovirus vector containing IL12-IRES-CKb gene on rabbit VX2 liver tumor model through detecting metabolic product of imaging reporter gene CKb (pCr).

Adenoviridae ; genetics ; Animals ; Creatine Kinase ; genetics ; metabolism ; Gene Expression ; Genetic Vectors ; Interleukin-12 ; genetics ; Liver Neoplasms, Experimental ; genetics ; pathology ; Magnetic Resonance Spectroscopy ; Rabbits

OBJECTIVEDiscusses the distributive characters of the Creatine Kinase MM (CKMM) gene A/G Polymorphism in XinjiangUyghur, One hundred and fourtheen athletes and 441 general population of Uyghur were involved in the study.

METHODSPolymerase chain reaction-restriction fragment length polymorphism was used.

RESULTS(1) The CKMM gene A/G frequency in Uyghur general population was(AA, AG and GG) 0.497, 0.392 and 0.111, the result test by Hardy-Weinberg (H-W) equilibrium and x² = 2.72, P = 0.1, df = 2, indicated that the control group had representative. (2) AA, AG and GG genotype frequency of power-oriented athlete respectively was 0.442,0.302 and 0.256, frequency of GG genotype and G allele was higher than the control group, there were significant differences compared to thecontrol( P < 0.05, df = 2); (3) A/G genotype frequency of Endurance-oriented athletere spectively was 0.571, 0.400 and 0.029, there were nosignificant differences compared to the controls ( P > 0. 05, df = 2). (4) A/G genotype frequency of Uyghur soccer athletes respectively was0.472, 0.361 and 0.167, G allele was higher than the Endurance-oriented athlete and lower than the power-oriented athletes. and no significant differences compared to the controls( P > 0.05, df = 2).

CONCLUSIONThe results indicate that the CKMM gene GG genotype and G alleleare represented in power-oriented athletes, but don't find A/G polymorphism correlation with endurance and the football sport performance.

Alleles ; Asian Continental Ancestry Group ; genetics ; Athletes ; Athletic Performance ; China ; Creatine Kinase, MM Form ; genetics ; Gene Frequency ; Genotype ; Humans ; Physical Endurance ; genetics ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length

OBJECTIVETo analyze the clinical features of 6 children with Duchenne muscular dystrophy (DMD) and review related literature, and to provide a basis for early diagnosis and effective treatment of this disease.

METHODSA retrospective analysis was performed on the clinical data of 6 children with DMD who were admitted to the First Affiliated Hospital of Nanjing Medical University from January 2010 to October 2015.

RESULTSAll the 6 cases were boys without a family history of DMD, and the age of diagnosis of DMD was 1.2-11.5 years. All patients had insidious onset and increases in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase, creatine kinase (CK), and creatine kinase-MB, particularly CK, which was 3.3-107.2 times the normal level. Their gene detection results all showed DMD gene mutation. The gene detection results of two children's mothers showed that they carried the same mutant gene. The muscle biopsy in one case showed that the pathological changes confirmed the diagnosis of DMD. The level of CK in one case declined by 77.0% 5 days after umbilical cord blood mesenchymal stem cell transplantation.

CONCLUSIONSFor boys with abnormal serum enzyme levels and motor function, DMD should be highly suspected. It should be confirmed by CK and DMD gene detection as soon as possible. And the progression of the disease could be delayed by early intervention for protecting the remaining normal muscle fibers.

Child ; Child, Preschool ; Cord Blood Stem Cell Transplantation ; Creatine Kinase ; genetics ; Dystrophin ; genetics ; Humans ; Infant ; Male ; Muscular Dystrophy, Duchenne ; genetics ; therapy ; Retrospective Studies

PURPOSE: Glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase (GNE) myopathy is an autosomal recessive neuromuscular disorder characterized by early adult-onset weakness of the distal muscles of the lower limbs. The clinical spectrum of GNE myopathy varies, and it is not clear how the same GNE gene mutations can result in different phenotypes. Here, we present clinical, pathological and genetic characteristics of twenty-one Korean patients with GNE myopathy. MATERIALS AND METHODS: Twenty-one GNE myopathy patients were included in this study, conducted from 2004 to 2011. Based on medical records, patients' gender, onset age, family history, clinical history, serum creatine kinase (CK) level, neurologic examination, findings of muscle biopsy, muscle imaging findings and electrophysiologic features were extensively reviewed. Mutation of the GNE gene (9p13.3) was confirmed by DNA direct sequencing analysis in all patients. RESULTS: The mean onset age was 23.8+/-8.8 years (mean+/-SD). Patient serum CK levels were slightly to moderately elevated, ranging from 41 to 2610 IU. Among the patients, twelve patients were female and nine patients were male. Except for eight patients, all of the patients presented initially with only distal muscle weakness in the lower extremities. The most common mutation was V572L, followed by C13S. CONCLUSION: The clinical manifestations of our patients with GNE mutations varied. Among twenty-one patients, thirteen patients showed the typical GNE myopathy phenotype. There was no relationship between clinical features and site of mutation. Therefore, we suggest that neither homozygous nor compound heterozygous models are correlated with disease phenotype or disease severity.
Adolescent ; Adult ; Creatine Kinase/blood ; Distal Myopathies/diagnosis/*genetics/pathology ; Female ; Humans ; Male ; Multienzyme Complexes/*genetics ; Republic of Korea ; Sequence Analysis, DNA

OBJECTIVETo screen for potential mutations of androgen receptor (AR) gene in a patient clinically diagnosed as Kennedy disease.

METHODSPolyglutamine expansion (PQE) induced by a duplication of CAG trinucleotide tandem-repeat in exon 1 of the AR gene was detected with PCR and T-clone sequencing.

RESULTSCompared with the number of CAG repeat of 22 in the normal allele, the number of CAG repeats has increased to 45 in the mutant allele carried by the patient. This has fit with the diagnostic criteria for Kennedy disease.

CONCLUSIONA mutation of PQE has been detected in the patient with Kennedy disease. Detection of PQE in AR gene can be used as reliable method to identify the Kennedy disease.

Base Sequence ; Bulbo-Spinal Atrophy, X-Linked ; blood ; diagnosis ; genetics ; Creatine Kinase ; blood ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Receptors, Androgen ; genetics ; Trinucleotide Repeat Expansion

This article reports the clinical and genetic features of two cases of cerebral creatine deficiency syndrome I (CCDSI) caused by SLC6A8 gene mutations. Both children were boys. Boy 1 (aged 2 years and 10 months) and Boy 2 (aged 8 years and 11 months) had the clinical manifestations of delayed mental and motor development, and convulsion. Their older brothers had the same symptoms. The mother of the boy 1 had mild intellectual disability. The genetic analysis showed two novel homozygous mutations, c.200G>A(p.Gly67Asp) and c.626_627delCT(p.Pro209Argfs*87), in the SLC6A8 gene on the X chromosome, both of which came from their mothers. These two novel mutations were rated as possible pathogenic mutations and were not reported in the literature before. This study expands the mutation spectrum of the SLC6A8 gene and has great significance in the diagnosis of boys with delayed development, and epilepsy.
Child ; Child, Preschool ; Creatine ; Epilepsy ; Genetic Testing ; Humans ; Male ; Mutation ; Nerve Tissue Proteins ; genetics ; Plasma Membrane Neurotransmitter Transport Proteins ; genetics ; Syndrome

OBJECTIVE: To explore the clinical features and genetic variant in a child with Cerebral creatine deficiency syndrome (CCDS). METHODS: A child who had presented at the Affiliated Children's Hospital of Fudan University on March 5, 2021 was selected as the study subject. Whole exome sequencing (WES) was carried out for the child, and candidate variant was verified by Sanger sequencing. The level of creatine in the brain was determined by magnetic resonance spectroscopy. RESULTS: The patient, a 1-year-and-10-month male, had presented with developmental delay and epilepsy. Both his mother and grandmother had a history of convulsions. MRS showed reduced cerebral creatine in bilateral basal ganglia and thalamus. The child was found to harbor a hemizygous splicing variant of the SLC6A8 gene, namely c.1767+1_1767+2insA, which may lead to protein truncation. The variant was not found in the public databases. Both his mother and grandmother were heterozygous carriers for the same variant. CONCLUSION The hemizygous c.1767+1_1767+2insA variant of the SLC6A8 gene probably underlay the CCDS in this child. Discovery of the novel variant has also expanded the mutational spectrum of the SLC6A8 gene.
Humans ; Male ; Amino Acid Metabolism, Inborn Errors ; Brain ; Creatine/genetics* ; Heterozygote ; Mothers ; Nerve Tissue Proteins ; Plasma Membrane Neurotransmitter Transport Proteins/genetics* ; Infant