Diagnosis of Spinal Muscular Atrophy: A Simple Method for Quantifying the Relative Amount of Survival Motor Neuron Gene 1/2 Using Sanger DNA Sequencing / 中华医学杂志(英文版)

Background@#Spinal muscular atrophy (SMA) is caused by homozygous deletion or compound heterozygous mutation of survival motor neuron gene 1 (SMN1), which is the key to diagnose SMA. The study was to establish and evaluate a new diagnostic method for SMA.@*Methods@#A total of 1494 children suspected with SMA were enrolled in this study. Traditional strategy, including multiplexed ligation-dependent probe amplification (MLPA) and TA cloning, was used in 1364 suspected SMA children from 2003 to 2014, and the 130 suspected SMA children were tested by a new strategy from 2015 to 2016, who were also verified by MLPA combined with TA cloning. The SMN1 and SMN2 were simultaneously amplified by polymerase chain reaction using the same primers. Mutation Surveyor software was used to detect and quantify the SMN1 variants by calculating allelic proportions in Sanger sequencing. Finally, turnaround time and cost of these two strategies were compared.@*Results@#Among 1364 suspected SMA children, 576 children had SMN1 homozygous deletion and 27 children had SMN1 compound heterozygous mutation. Among the 130 cases, 59 had SMN1 homozygous deletion and 8 had heterozygous deletion: the SMN1-specific peak proportion on exon 7 was 34.6 ± 1.0% and 25.5 ± 0.5%, representing SMN1:SMN2 to be 1:2 and 1:3, respectively. Moreover, five variations, including p.Ser8Lysfs *23 (in two cases), p.Leu228*, p.Pro218Hisfs *26, p.Ser143Phefs*5, and p.Tyr276His, were detected in 6/8 cases with heterozygous deletion, the mutant allele proportion was 31.9%, 23.9%, 37.6%, 32.8%, 24.5%, and 23.6%, which was similar to that of the SMN1-specific site on exon 7, suggesting that those subtle mutations were located in SMN1. All these results were consistent with MLPA and TA cloning. The turnaround times of two strategies were 7.5 h and 266.5 h, respectively. Cost of a new strategy was only 28.5% of the traditional strategy.@*Conclusion@#Sanger sequencing combined with Mutation Surveyor analysis has potential application in SMA diagnosis.

Role of Diffusion-weighted and Contrast-enhanced Magnetic Resonance Imaging in Differentiating Activity of Ankylosing Spondylitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies showed that combining apparent diffusion coefficient (ADC) value with the Spondyloarthritis Research Consortium of Canada (SPARCC) index value might provide a reliable evaluation of the activity of ankylosing spondylitis (AS), and that contrast-enhanced (CE) magnetic resonance imaging (MRI) is unnecessary. However, the results were based on confirming only a small random sample. This study aimed to assess the role of CE-MRI in differentiating the disease activity of AS by comparing ADC value with a large sample.</p><p><b>METHODS</b>A total of 115 patients with AS were enrolled in accordance with Bath AS Disease Activity Index and laboratory indices, and 115 patients were divided into two groups, including active group (n = 69) and inactive group (n = 46). SPARCC, ΔSI, and ADC values were obtained from the short tau inversion recovery (STIR), diffusion-weighted imaging (DWI), and CE-MRI, respectively. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters.</p><p><b>RESULTS</b>The optimal cutoff values (with sensitivity, specificity, respective area under the curve, positive likelihood ratio, and negative likelihood ratio) for the differentiation between active and inactive groups are as follows: SPARCC = 6 (72.06%, 82.61%, 0.836, 4.14, 0.34); ΔSI (%) = 153 (80.6%, 84.78%, 0.819, 5.3, 0.23); ADC value = 1.15 × 10-3 mm2/s (72.73%, 81.82%, 0.786, 4, 0.33). No statistical differences were found among the predictive values of SPARCC, ΔSI, and ADC. Multivariate analysis showed no significant difference between the combination of SPARCC and ADC values with and without ΔSI.</p><p><b>CONCLUSIONS</b>Using large sample, we concluded that the combination of STIR and DWI would play significant roles in assessing the disease activity, and CE-MRI sequence is not routinely used in imaging of AS to avoid renal fibrosis and aggravation of kidney disease.</p>

The correlation study on syndrome differentiation of rheumatoid arthritis and joint high frequency ultrasound performance / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the differential effect of joint ultrasound on the syndrome differentiation of rheumatoid arthritis (RA) by observing the high frequency ultrasound performances among inactive stage and different syndromes in active stage.</p><p><b>METHODS</b>Totally 83 RA patients in the active stage were assigned to the dampness heat syndrome group (DHS, 59 cases)and the cold dampness syndrome group (CDS, 24 cases) according to Chinese medicine (CM) syndrome typing. Besides, 20 RA patients in the remission stage were recruited as the control group (abbreviated as the remission group). By using high frequency ultrasound and power Doppler ultrasound technology, a comparative observation of synovitis, tenosynovitis, synovial blood flow, and bone erosion in the 2nd-5th metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, wrist joints, knee joints, the second and the fifth metatarsophalangeal (MTP) joints (a total of 24 joints) was performed in all patients. Correlation analyses were performed between the ultrasound performance, laboratory indices, and the disease activity. Ultrasound data of each RA patient were analyzed by their total scores. Χ2 test was used for enumeration data. The measurement data was expressed as x ± s. One-way ANOVA was used for data of normal distribution, while non- parametric test was used for data of non-normal distribution. Correlation analysis of two variables was performed for clinical indicators and ultrasound indicators. Its significance was detected using Pearson correlation.</p><p><b>RESULTS</b>Compared with the remission group, the severity degree of synovitis, tenosynovitis, synovial blood flow, and bone erosion significantly increased in the DHS group (P < 0.01). There was statistical difference in ESR, CRP, anti-CCP, DAS28 score, and the positive rate of RF (P < 0.05, P < 0.01). There was statistical difference in the severity degree of synovitis and synovial blood flow, and DAS28 score in the CDS group (P < 0.05). Compared with the CDS group, there was statistical difference in the four ultrasound indices (P < 0.05, P < 0.01), ESR, CRP, anti-CCP, DAS28 score, and the positive rate of RF in the DHS group (P < 0.05, P < 0.01). There was no statistical difference in G, IgG, IgA, or IgM among the three groups (P > 0.05). There existed positive correlation between ESR and the synovitis degree, synovial blood flow, and bone erosion in the DHS group (r = 0.444, 0.397, 0.486, P < 0.05).There existed positive correlation between ESR and the synovitis degree, bone erosion, and synovial blood flow in the DHS group (r = 0.378, 0.270, P < 0.05). There existed positive correlation between the DAS28 score and the synovitis degree and synovial blood flow in the DHS group (r = 0.304, 0.351, P < 0.05).</p><p><b>CONCLUSIONS</b>The inflammation degree was the most severe in RA patients of DHS. High frequency ultrasound could provide better evidence for Chinese medical syndrome differentiation of RA patients.</p>

Detection of homozygous deletions in spinal muscular atrophy with genomic DNA sequencing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect homozygous deletions of survival motor neuron (SMN) gene with genomic DNA sequencing, and to assess the value of genetic testing for the diagnosis of spinal muscular atrophy (SMA).</p><p><b>METHODS</b>Polymerase chain reaction (PCR) was used for amplifying SMN gene in 100 SMA patients and 110 controls. Four different bases (g.31957, g.32006, g.32154 and g.32269) between SMN1 and SMN2 within the amplified segments were identified with genomic DNA sequencing. Homozygous deletion of SMN1 or SMN2 was determined by the presence or absence of base peaks at such four sites. Multiplex ligation-dependent probe amplification (MLPA) was carried out to confirm the results of genomic DNA sequencing.</p><p><b>RESULTS</b>In the 100 SMA samples, only SMN2 specific base peaks were detected at the four sites, for which the copy numbers of SMN1 and SMN2 was 0:2 or 0:3, suggesting homozygous deletion of SMN1 gene. By contrast, only SMN1 specific base peaks were detected in 5 samples, for which the ratio of SMN1:SMN2 was 2:0, indicating homozygous deletion of SMN2. At four different sites, SMN1/SMN2 heterozygous peaks were detected in the remaining 105 samples, for which SMN1:SMN2was 2:2, suggesting non-deletion of SMN1 or SMN2. The results of sequencing were consistent with those of MLPA.</p><p><b>CONCLUSION</b>Genomic DNA sequencing is a rapid, accurate and economic method for the diagnosis of homozygous deletion of SMA.</p>

Compound mutations (R237X and L375P) in the fumarylacetoacetate hydrolase gene causing tyrosinemia type I in a Chinese patient / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Mutations in fumarylacetoacetate hydrolase (FAH) gene can lead to tyrosinemia type 1 (HT1), a relatively rare autosomal recessive disorder. To date, no molecular genetic defects of HT1 in China have been described. We investigated a Chinese family with a HT1 child to identify mutations in FAH.</p><p><b>METHODS</b>DNA sequencing was used for mutations screening in FAH gene. Real-time polymerase chain reaction (PCR) was performed to determine the FAH gene expression level. To confirm the presence of degradation by the nonsense-mediated mRNA decay pathway (NMD), the fragments containing R237X mutations were analyzed by primer introduced restriction analysis-polymerase chain reaction (PIRA-PCR) and cDNA sequencing. Finally, the effects of the mutations reported in this study were predicted by online softwares.</p><p><b>RESULTS</b>A boy aged 3 years and 8 months was diagnosed clinically with HT1 based on his manifestations and biochemical abnormalities. Screening of FAH gene revealed two heterozygous mutations R237X and L375P transmitted from his mother and father respectively. In this pedigree, the amount of FAH mRNA relative to a healthy control was 0.44 for the patient, 0.77 for his mother and 1.07 for his father. Moreover, both PIRA-PCR and cDNA sequencing showed significant reduction of the FAH mRNA with R237X nonsense mutation. The missense mutation of L375P was not reported previously and prediction software showed that this mutation decreased the stability of protein structure and affected protein function.</p><p><b>CONCLUSIONS</b>This is the first case of HT1 analyzed by molecular genetics in China. The R237X mutation in FAH down- regulates the FAH gene expression, and the L375P mutation perhaps interrupts the secondary structure of FAH protein.</p>

Association of the MDM2 polymorphisms with susceptibility of esophageal squamous cell carcinoma and that of gastric cardiac adenocarcinoma / 肿瘤

Objective: To investigate the correlation between the SNP309 and Del1518 polymorphisms in the promoter region of murine double minute 2 (MDM2) and genetic susceptibilities of esophageal squamous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA). Methods: Genotypes of the MDM2 polymorphisms of 563 cancer patients (351 ESCC and 212 GCA) and 642 healthy controls were detected by a primer-introduced restriction analysis-polymerase chain reaction (PIRA-PCR). The combined effects of MDM2 polymorphisms were analyzed by EH and 2LD softwares. Results: Distributions of the MDM2 genotypes in both ESCC patients and healthy controls were not significantly different (P > 0.05), however, a significant different distribution between GCA patients and healthy controls was observed (P < 0.05). The MDM2 haplotype distributions were not significantly different between ESCC patients and healthy controls (P = 0.198). MDM2 haplotype distribution in the GCA patients was also significantly different from that in the healthy controls (P 0. 000). Compared with SNP309G/Del1518 + haplotype, SNP309T/Del1518 - haplotype significantly decreased the risk of developing GCA (adjusted OR = 0.51, 95% CI = 0.38-0.70). Conclusions: MDM2 polymorphisms may not be associated with susceptibility to ESCC. Individuals with MDM2 SNP309T allelotype (G/T and T/T genotype) and with Del1518 - allelotype (+/- and -/- genotype) have significantly lower risk of developing GCA, respectively. Individuals T/Del1518 - haplotype have significantly lower risk of developing GCA.