A "Triple Trouble" Case of Facioscapulohumeral Muscular Dystrophy Accompanied by Peripheral Neuropathy and Myoclonic Epilepsy / 中华医学杂志(英文版)

<p><b>Background</b>Facioscapulohumeral muscular dystrophy (FSHD) is characterized by asymmetric muscular deficit of facial, shoulder-girdle muscles, and descending to lower limb muscles, but it exists in several extramuscular manifestations or overlapping syndromes. Herein, we report a "complex disease plus" patient with FSHD1, accompanied by peripheral neuropathy and myoclonic epilepsy.</p><p><b>Methods</b>Standard clinical assessments, particular auxiliary examination, histological analysis, and molecular analysis were performed through the new Comprehensive Clinical Evaluation Form, pulsed-field gel electrophoresis-based Southern blot, Multiplex Ligation-dependent Probe Amplification (MLPA), whole exome sequencing (WES), and targeted methylation sequencing.</p><p><b>Results</b>The patient presented with mild facial weakness, humeral poly-hill sign, scapular winging, peroneal weakness, drop foot, pes cavus, and myoclonic epilepsy. Furthermore, electrophysiology revealed severely demyelinated and axonal injury. The muscle and nerve biopsy revealed broadly fiber Type II grouping atrophy and myelinated nerve fibers that significantly decreased with thin myelinated fibers and onion bulbs changes. Generalized sharp and sharp-slow wave complexes on electroencephalography support the diagnosis toward myoclonic epilepsy. In addition, molecular testing demonstrated a co-segregated 20-kb 4q35-EcoRI fragment and permissive allele A, which corresponded with D4Z4 hypomethylation status in the family. Both the patient's mother and brother only presented the typical FSHD but lacked overlapping syndromes. However, no mutations for hereditary peripheral neuropathy and myoclonic epilepsy were discovered by MLPA and WES.</p><p><b>Conclusions</b>The present study described a "tripe trouble" with FSHD, peripheral neuropathy, and myoclonic epilepsy, adding the spectrum of overlapping syndromes and contributing to the credible diagnosis of atypical phenotype. It would provide a direct clue on medical care and genetic counseling.</p>

A Historical Cohort Study on the Efficacy of Glucocorticoids and Riboflavin Among Patients with Late-onset Multiple Acyl-CoA Dehydrogenase Deficiency / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is the most common type of lipid storage myopathies in China. Most patients with late-onset MADD are well responsive to riboflavin. Up to now, these patients are often treated with glucocorticoids as the first-line drug because they are misdiagnosed as polymyositis without muscle biopsy or gene analysis. Although glucocorticoids seem to improve the fatty acid metabolism of late-onset MADD, the objective evaluation of their rationalization on this disorder and comparison with riboflavin treatment are unknown.</p><p><b>METHODS</b>We performed a historical cohort study on the efficacy of the two drugs among 45 patients with late-onset MADD, who were divided into glucocorticoids group and riboflavin group. Detailed clinical information of baseline and 1-month follow-up were collected.</p><p><b>RESULTS</b>After 1-month treatment, a dramatic improvement of muscle strength was found in riboflavin group (P < 0.05). There was no significant difference in muscle enzymes between the two groups. Significantly, the number of patients with full recovery in glucocorticoids group was less than the number in riboflavin group (P < 0.05). On the other hand, almost half of the patients in riboflavin group still presented high-level muscle enzymes and weak muscle strength after 1-month riboflavin treatment, meaning that 1-month treatment duration maybe insufficient and patients should keep on riboflavin supplement for a longer time.</p><p><b>CONCLUSIONS</b>Our results provide credible evidences that the overall efficacy of riboflavin is superior to glucocorticoids, and a longer duration of riboflavin treatment is necessary for patients with late-onset MADD.</p>

Skeletal Muscle Magnetic Resonance Imaging of the Lower Limbs in Late-onset Lipid Storage Myopathy with Electron Transfer Flavoprotein Dehydrogenase Gene Mutations / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Lipid storage myopathy (LSM) is a genetically heterogeneous group with variable clinical phenotypes. Late-onset multiple acyl-coenzyme A dehydrogenation deficiency (MADD) is a rather common form of LSM in China. Diagnosis and clinical management of it remain challenging, especially without robust muscle biopsy result and genetic detection. As the noninvasion and convenience, muscle magnetic resonance imaging (MRI) is a helpful assistant, diagnostic tool for neuromuscular disorders. However, the disease-specific MRI patterns of muscle involved and its diagnostic value in late-onset MADD have not been systematic analyzed.</p><p><b>METHODS</b>We assessed the MRI pattern and fat infiltration degree of the lower limb muscles in 28 late-onset MADD patients, combined with detailed clinical features and gene spectrum. Fat infiltration degree of the thigh muscle was scored while that of gluteus was described as obvious or not. Associated muscular atrophy was defined as obvious muscle bulk reduction.</p><p><b>RESULTS</b>The mean scores were significantly different among the anterior, medial, and posterior thigh muscle groups. The mean of fat infiltration scores on posterior thigh muscle group was significantly higher than either anterior or medial thigh muscle group (P < 0.001). Moreover, the mean score on medial thigh muscle group was significantly higher than that of anterior thigh muscle group (P < 0.01). About half of the patients displayed fat infiltration and atrophy in gluteus muscles. Of 28 patients, 12 exhibited atrophy in medial and/or posterior thigh muscle groups, especially in posterior thigh muscle group. Muscle edema pattern was not found in all the patients.</p><p><b>CONCLUSIONS</b>Late-onset MADD patients show a typical muscular imaging pattern of fat infiltration and atrophy on anterior, posterior, and medial thigh muscle groups, with major involvement of posterior thigh muscle group and gluteus muscles and a sparing involvement of anterior thigh compartment. Our findings also suggest that muscle MRI of lower limbs is a helpful tool in guiding clinical evaluation on late-onset MADD.</p>

New Insights into Genotype-phenotype Correlations in Chinese Facioscapulohumeral Muscular Dystrophy: A Retrospective Analysis of 178 Patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Facioscapulohumeral muscular dystrophy (FSHD), a common autosomal dominant muscular disorder, is caused by contraction of the D4Z4 repeats on 4q35. The complicated genotype-phenotype correlation among different ethnic population remains a controversial subject. We aimed to refine this correlation in order to provide new information for genetic counseling.</p><p><b>METHODS</b>Here, a cohort of 136 Chinese families including 178 affected individuals and 137 unaffected members were investigated. Genetic analyses were performed using the p13E-11, 4qA and 4qB probes after pulsed field gel electrophoresis separation and southern blotting. A 10-grade FSHD clinical severity scale was adopted for clinical assessment. The genotype-phenotype correlation was established by linear regression analyses.</p><p><b>RESULTS</b>We observed a roughly inversed correlation between the short EcoRI fragment size and age-corrected clinical severity score in 154 symptomatic patients (P < 0.05). Compared to male patients, a significant higher proportion of females in both asymptomatic carriers and severe patients showed larger variation in the size of short EcoRI fragment. A high incidence (19/42, 45.2%) of asymptomatic (or minimally affected) carriers was found in familial members.</p><p><b>CONCLUSIONS</b>Although the number of D4Z4 repeats is known as one of the critical influences on genotype-phenotype correlation, a majority of phenotypic spectrum was still incompatible with their heterozygous contraction of the D4Z4 repeat, especial in female cases. Our results suggest that there are multi-factors synergistically modulating the phenotypic expression.</p>

Prevalence of CYP2C19 polymorphisms involved in clopidogrel metabolism in Fujian Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the frequency of CYP2C19 polymorphisms involved in clopidogrel metabolism in Fujian Han population.</p><p><b>METHODS</b>Frequencies of CYP2C19* 2, CYP2C19*3 and CYP2C19*17 in 1001 unrelated Fujian Han volunteers were determined with polymerase chain reaction-restriction fragment length polymorphism and direct sequencing method.</p><p><b>RESULTS</b>The frequencies of CYP2C19*2, *3 and *17 were 32.4%, 5.8% and 0.4%, respectively. According to genotyping results, intermediate metabolizers (CYP2C19 *1/*2 or *1/*3) and poor metabolizers (CYP2C19 *2/*2 and *2/*3) respectively accounted for 47.95% and 13.99% of all subjects. Above frequencies were similar to those of Japan, Korea, Singapore, Malaysia, Thailand and Chinese Dai, Mongolian,Li and Hui ethnics (P>0.05), but were significantly different from those of Chinese Kazakh and Uygur ethnics, and people from Iran, Russia, Italy, Poland, Norway, Canada native Indians, Bolivia, Egypt or Tanzania (P<0.05).</p><p><b>CONCLUSION</b>Ethnic/regional diversity exist with regard to the prevalence of CYP2C19 polymorphisms. No significant difference were found between Fujian Han Chinese and Dai, Mongolian, Li and Hui from China or other populations from East and Southeast Asia, but higher frequencies of intermediate metabolizers and poor metabolizers compared with populations of Kazakh and Uygur in China, and people from Europe, South America and Africa.</p>

Analysis of alleles 4qA and 4qB of the chromosome 4q subtelomere in Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze two alleles (4qA and 4qB) distal to D4Z4 of the 4q subtelomere in Chinese population, and to elucidate the interrelationship between these variants of 4qter and facioscapulohumeral muscular dystrophy (FSHD).</p><p><b>METHODS</b>Eighty unrelated healthy individuals from a random Chinese Han population were investigated. The genomic DNA was extracted from peripheral blood lymphocytes according to the specific procedure designed to minimize DNA shearing, then digested with EcoRI, HindIII or double digested with EcoRI and BlnI. The cleaved DNA was separated by pulsed field gel electrophoresis (PFGE) and Southern blotting with the probes p13E-11, 4qA and 4qB. The sizes of 4q35 EcoRI/4qA and EcoRI/4qB arrays were obtained by "curve fitting", and the frequencies of alleles and genotypes were calculated. Data were analyzed using a commercially available statistical package (Version 13.0 SPSS).</p><p><b>RESULTS</b>In normal individuals, frequencies of 4qA and 4qB alleles (46.9% and 53.1%) were observed of no significant difference (chi(2) = 1.250, P>0.05). The frequency of 4qA/4qB heterozygote was much higher than that of homozygote (P<0.05). The means of EcoRI/4qA and EcoRI/ 4qB arrays (115.8+/-11.9 kb and 98.3+/-8.6 kb) were of significant difference (t=23.04, P<0.001). 8.8% (7/80) of the individuals displayed a translocation repeat array configuration. 4qB-type EcoRI arrays smaller than 35 kb were found in two individuals.</p><p><b>CONCLUSION</b>The structural polymorphism of 4qA/4qB alleles within 4q35 and 10q26 is confirmed using PFGE in normal Chinese Han population. Although both alleles are almost equally common, shorten 4qB-type EcoRI fragment is not pathogenic. The frequency of 4qA/4qB heterozygote is significantly higher than that of homozygote.</p>

Clinical analysis of dopa-responsive dystonia and mutation analysis of the GCH I gene / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the clinical characteristics and GCH I gene mutations in patients with dopa-responsive dystonia (DRD).</p><p><b>METHODS</b>The clinical features of 3 families with 6 affected members and 8 sporadic cases were analyzed to determine the clinical characteristics, and 2 families with 4 affected members and 2 sporadic cases were screened for mutations of the GCH I gene.</p><p><b>RESULTS</b>Age at onset was (10 +/- 3) years. Onset occurred earlier in female (9 +/- 4) years than in male (12 +/- 1) years. The initial symptom was a gait disorder, dystonia or tremor in most patients and nine patients (64%) presented with diurnal fluctuation. Thirteen patients (93%) were cured and one was improved after administration of low doses of levodopa for 3 months and no long-term side effects of levodopa had occurred. Two independent mutations were found in three patients. Gln161Pro, a new missense mutation, was found in a sporadic case, leading to a relatively severe phenotype. The two patients with mild phenotype in one family were found to have Lys224Arg mutation, as previously described.</p><p><b>CONCLUSIONS</b>DRD patients have diverse phenotypes and diurnal fluctuation is an important feature. They have dramatic and sustained response to levodopa. There may be a correlation between genotype and phenotype. The detection of GCH I mutations is helpful in early diagnosis of non-typical cases.</p>

Rapid diagnosis of spinal muscular atrophy using denaturing high-performance liquid chromatography / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To introduce the application of denaturing high-performance liquid chromatography (DHPLC) in the diagnosis of childhood type spinal muscular atrophy (SMA).</p><p><b>METHODS</b>Exon 7 and flanking area of survival motor neuron (SMN) gene were amplified by PCR in 1 standard sample, 25 normal individuals and 25 patients with SMA. The PCR products were then directly loaded onto the DHPLC system after denaturing and annealing. Different DNA segments were separated by changing the concentration of buffer A relative to that of buffer B.</p><p><b>RESULTS</b>Different DNA segments were separable on the DHPLC chromatogram. Three peaks including SMN1/SMN2 heteroduplex peak, SMN2 homoduplex peak and SMN1 homoduplex peak were detected in 23 out of 25 normal individuals. Only SMN1 homoduplex peak was detected in 2 normal individuals and the standard sample, indicating the deletion of SMN2 On the contrary, only the SMN2 homoduplex peak was detected in 22 out of 25 patients with SMA, indicating deletion of SMN1. The three peaks as those of normal individuals were detected in the other 3 patients, indicating no SMN1 or SMN2 deletion.</p><p><b>CONCLUSION</b>As a new technology for diagnosing SMA, DHPLC is sensitive, accurate, rapid and convenient.</p>

Quantitative studies on SMN1 gene and carrier testing of spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To construct a method for detecting the copy number of survival of motor neuron 1 gene (SMN1) with single copy difference based on real-time fluorescence quantitative PCR, and to make practical use of the method for acquiring the data on SMN1 copy number in Chinese as well as for screening the carriers of spinal muscular atrophy (SMA) from healthy individuals and SMA families.</p><p><b>METHODS</b>Exon 7 and flanking area of SMN1 gene were amplified by real-time fluorescence quantitative PCR in 264 healthy individuals, in 1 standard sample having 2 SMN1 but having no SMN2, and in 88 parents of SMA patients. The samples for detecting were diluted to 30 ng/microL and the standard sample was diluted to 15 ng/microL, 30 ng/microL, 45 ng/microL, 60 ng/microL; the unknown samples and 4 standard samples with different concentrations were amplified at the same time, a standard curve could be drawn out according to the results of the 4 standard samples, then the copy number of samples could be calculated.</p><p><b>RESULTS</b>Of 88 parents' samples, 84 samples each had 1 copy of SMN1, and the rest 4 each had 2 copies of SMN1. Of 264 healthy individuals' samples, 5 samples each had only 1 copy of SMN1 (an indicator of definite gene carriers), 232 samples each had 2 copies of SMN1, 25 samples each had 3 copies of SMN1, and 2 samples each had 4 copies of SMN1. Of the samples of 32 members of SMA families, 2 samples each had only 1 copy of SMN1 indicating definite gene carriers, 25 samples each had 2 copies of SMN1, and 5 samples each had 3 copies of SMN1.</p><p><b>CONCLUSION</b>SMN1 copy number could be detected precisely by real-time fluorescence quantitative PCR; the screening of gene carriers could provide essential data for genetic counseling.</p>

Preparation of polyclonal antibody against survival motor neuron protein and study on the expression of survival motor neuron protein in the skeletal muscular of patients with spinal muscular atrophy / 中华神经科杂志

Objective To prepare the survival motor neuron(SMN)polyclonal antibody and explore the localization of SMN protein in transfected cells and its expression in skeletal muscles of patients with spinal muscular atrophy(SMA).Methods A prokaryotic expressional plasmid named pET-28? (+)/SMN was constructed and SMN-His fusion protein was induced.The fusion protein was used to immunize New Zealadd rabbits to prepare SMN polyclonal antibody.A eukaryotic expressional plasmid named pcDNA3.1/myc-HisB-SMN was constructed and used to transfect CHO cells.Skeletal muscles were collected from 3 patients with bone fracture who were regarded as normal controls, and 3 SMA patients of type Ⅰ, 3 of type Ⅱ and 3 of type Ⅲ who were ascertained by genetic analysis.Western-blotting and immunofluorescence stain were applied to study the expression of SMN in transfected CHO cells and skeletal muscles of normal individuals and SMA patients.Results Correct pET-28a(+)/SMN prokaryotic expressive plasmid was constructed and SMN-His fusion protein was obtained from E coli BL21 transformed with pET-28a(+)/SMN.Then, rabbit anti-human full-length SMN polyclonal antibody of high specificity and sensitivity was obtained from rabbits immunized by SMN-His fusion protein.SMN proteins were shown diffusedly locating in the cytoplasm and nucleus of CHO cells transfected with pcDNA3.1/myc-HisB-SMN plasmid and mainly accumulating around the nucleus.The results of Western-blotting were as follows:the average ratio of SMN band density to glyceraldehyde phosphate dehydrogenase(GAPDH)band density (SMN/GAPDH)is 0.619 in skeletal muscles from normal controls, the average values of SMN/GAPDH in skeletal muscle from SMA patients of type Ⅲ and Ⅱ were 0.347 and 0.340 respectively, which were lower than that of normal controls.However, the average values of SMN/GAPDH in skeletal muscle from SMA patients of type I was only 0.079, which was quite lower than that of normal controls.Conclusions The rabbit anti-human full-length SMN polyclonal antibody is of high specificity and sensitivity, which makes the basis for the research of SMN function and SMA pathogenesis.There may be a correlation between the SMN level in skeletal muscle and the severity of disease.

Optimization of short tandem repeats and their application in prenatal diagnosis of spinal muscular atrophy / 中华神经科杂志

Objective To optimize the short tandem repeats(STR)which link closely to survival motor neuron(SMN)and have redundant polymorphism information contents,and to use these STR in the prenatal diagnosis of spinal muscular atrophy(SMA).Methods Eleven STR loci(D5S435,D5F153, DSF151,D5S637,D5S1413,D5S125,D5S464,D5S1556,DSF149,D5S351,MAP1B-5')were amplified by PCR.Then the PCR products were detected by polyacrylamide gel electrophoresis(PAGE)and analyzed by silver staining.STR loci were evaluated and optimized by their PIC values.PCR-PAGE and gene scan were combined to make genetic link analysis for SMA families based on the optimized STR.Results Three STR loci(D5S435,DSF149 and D5S351)were selected with 8,19 and 18 polymorphic fragments detected respectively in 100 normal individuals.Their PIC values were 0.84,0.91 and 0.92 respectively.Four carriers and 2 normal individuals were detected from 6 SMA families with linkage analysis by using the 3 STR.Conclusion This genetic diagnosis system based on the 3 STR loci can provide rapid prenatal diagnosis for SMA families,can eliminate maternal blood contamination,and also can discriminate carriers from normal individuals in the fetuses,which makes the prenatal diagnosis system of SMA perfect.

Study on EcoR I fragment polymorphism of the subtelomeric domains within 4q35 and 10q26 with pulsed field gel electrophoresis in the Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To elucidate the structural polymorphism of EcoR I fragment within chromosomes 4q35 and 10q26 in the Chinese population and investigate the relationship of plasticity, translocation and somatic mosaicism in these domains with deletion of D4Z4 repeated units.</p><p><b>METHODS</b>One hundred and ten unrelated healthy individuals from a random Chinese population were investigated. The genomic DNA was extracted from peripheral blood lymphocytes according to the specific procedure designed to minimize DNA shearing, then digested with EcoR I or double digested with EcoR I and Bln I. The cleaved DNA was separated by pulsed field gel electrophoresis (PFGE) and Southern blotted with the probe p13E-11. The sizes of EcoR I fragments were calculated by "curve fitting" according to the MidRange PFG marker and the alleles were assigned to their respective chromosomes based on their Bln I sensitivity. Data were analyzed using a commercially available statistical package (Version 11.0 SPSS).</p><p><b>RESULTS</b>Seventy-seven point three per cent (85/110) of the unrelated healthy individuals displayed a standard configuration distribution. The mean and median of 4q35 repeat arrays are (87.9+/-3.3) kb and 78.5 kb respectively, whereas the mean and median of 10q26 homologous arrays are (90.1+/-4.1) kb and 73.0 kb. Repeat size distributions between both of them were of no significance according to the t test (P>0.05). 19.1% (21/110) of the individuals displayed a translocation repeat array configuration on chromosomes 4 and 10. No significant difference was detected between 4q-->10q translocation and 10q-->4q translocation according to Chisquare test (Chi2 test=0.053, P>0.05). Somatic mosaicism was observed in 3.6% (4/110) of the subjects and less than 35 kb 10-type array was found in 14.5% (16/110) of the individuals.</p><p><b>CONCLUSION</b>The structural polymorphism and dynamic behaviors of EcoR I fragments within 4q35 and 10q26 were demonstrated in this study using PFGE. The occurrence of frequent translocations and somatic mosaicism between 4q35 and 10q26 subtelomeric domains in the Chinese population further confirmed that mitotic interchromosomal gene conversion or translocation might be a major mechanism relating to the deletion of D4Z4 units.</p>

The quantitative analysis of protein particles of erythrocyte membrane from Duchenne muscular dystrophy patients and the gene carriers / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the changes of the intramembrane protein particles of erythrocyte from Duchenne muscular dystrophy (DMD) patients and the gene carriers and to explore the pathogenesis of DMD and the diagnostic value of erythrocyte freeze-fracture technology.</p><p><b>METHODS</b>The fixed erythrocyte mass was treated to form replica membrane by means of the freeze-fracture technology. Then the replica membrane was observed and a picture was taken under electron microscope. The protein particles of extracellular face(EF) and protoplasmic face(PF) per square were counted. The statistical comparative analysis was performed.</p><p><b>RESULTS</b>The protein particle counts of EF face and PF face of erythrocyte membrane from DMD patients and DMD carriers decreased obviously in comparison with the normal control group (P<0.001).</p><p><b>CONCLUSION</b>The erythrocyte freeze-fracture electron microscopic technology may serve as a method for accessory examination of diagnosing DMD patients and a method for detecting DMD carriers. This investigation material supplies reliable evidence for the theory of the systemic membrane defect of DMD.</p>