[Clinical, genetic, and pathological analysis in 165 children with disorders of sex development]. / 165ä¾‹å„¿ç«¥æ€§å‘è‚²å¼‚å¸¸ç–¾ç— çš„ä¸´åºŠã€é—ä¼ å­¦ä¸Žç— ç†å­¦åˆ†æž.

OBJECTIVES: To investigate the clinical phenotypes, genetic characteristics, and pathological features of children with disorders of sex development (DSD). METHODS: A retrospective analysis was conducted on epidemiological, clinical phenotype, chromosomal karyotype, gonadal pathology, and genotype data of 165 hospitalized children with DSD at Children's Hospital of Hebei Province and Tangshan Maternal and Child Health Hospital from August 2008 to December 2022. RESULTS: Among the 165 children with DSD, common presenting symptoms were short stature (62/165, 37.6%), clitoromegaly (33/165, 20.0%), cryptorchidism (28/165, 17.0%), hypospadias (24/165, 14.5%), and skin pigmentation abnormalities/exteriorized pigmented labia majora (19/165, 11.5%). Chromosomal karyotype analysis was performed on 127 cases, revealing 36 cases (28.3%) of 46,XX DSD, 34 cases (26.8%) of 46,XY DSD, and 57 cases (44.9%) of sex chromosome abnormalities. Among the sex chromosome abnormal karyotypes, the 45,X karyotype (11/57, 19%) and 45,X/other karyotype mosaicism (36/57, 63%) were more common. Sixteen children underwent histopathological biopsy of gonadal tissues, resulting in retrieval of 25 gonadal tissues. The gonadal tissue biopsies revealed 3 cases of testes, 3 cases of dysplastic testes, 6 cases of ovaries, 11 cases of ovotestes, and 1 case each of streak gonad and agenesis of gonads. Genetic testing identified pathogenic/likely pathogenic variants in 23 cases (23/36, 64%), including 12 cases of 21-hydroxylase deficiency congenital adrenal hyperplasia caused by CYP21A2 pathogenic variants. CONCLUSIONS: Short stature, clitoromegaly, cryptorchidism, hypospadias, and skin pigmentation abnormalities are common phenotypes in children with DSD. 45,X/other karyotype mosaicism and CYP21A2 compound heterozygous variants are major etiological factors in children with DSD. The most commonly observed gonadal histopathology in children with DSD includes ovotestes, ovaries, and testes/dysgenetic testes.

Dexmedetomidine Reduces the Lidocaine-Induced Neurotoxicity by Inhibiting Inflammasome Activation and Reducing Pyroptosis in Rats.

Local anesthetic toxicity is closely related to neuronal death and activation of the inflammatory response. Dexmedetomidine (Dex) is an adrenergic α2 receptor agonist that can reduce the neurotoxicity induced by lidocaine. It also has anti-inflammatory effects. However, the mechanism underlying the neuroprotective effects of Dex against lidocaine-induced toxicity remains to be defined. We hypothesized that Dex exerts its neural protective effect through inhibiting inflammasome activation and through anti-pyroptosis effects against local anesthetic-induced nerve injury. In a rat model of lidocaine-induced spinal cord injury, we studied the protective effect of Dex on lidocaine-induced changes in spinal cord function, inflammasome formation and pyroptosis, pro-inflammatory cytokine expression, and protein kinase C (PKC)-δ phosphorylation. Dex reduced lidocaine-induced neurotoxicity and inhibited PKC-δ phosphorylation in the spinal cord of rats. Furthermore, Dex inhibited pyroptosis and inflammasome formation (caspase-1, NLRP3, and apoptosis-associated speck-like protein (ASC)). Finally, Dex attenuated interleukin (IL)-1ß and IL-18 expression, as well as microglia response. In conclusion, Dex can reduce the severity of lidocaine-induced spinal cord injury in rats by inhibiting priming and inflammasome activation and reducing pyroptosis via PKC-δ phosphorylation.

[The NMD escape mechanism and its application in disease therapy].

Nonsense-mediated mRNA decay (NMD) refers to the degradation of mRNA due to the presence of premature stop codon (PTC) on mRNA under pathological or physiological conditions. NMD is widely considered an mRNA-specific quality control process. Recently it was discovered that some PTCs do not trigger NMD in a variety of diseases - a process known as NMD escape; however, its exact mechanism remains unclear. At present, there are two widely accepted mechanistic hypotheses during NMD escape. The first is PTC read-through, in which protein translation undergoes PTC until the normal stop codon is encountered, producing a full-length protein. The second is translation reinitiation, in which protein translation recommences at the potential start codon downstream of PTC and terminates at the stop codon, producing an N-terminal truncated protein. Currently, an increasing number of drugs or small molecules that use PTC read-through have been successfully applied to treat nonsense variation-associated diseases. In this review, we summarize the NMD mechanism and discuss the application and progress in our understanding of NMD escape in disease therapy. This review should provide a useful framework to advance current understanding of the research and application of NMD escape.

Tuning of nanofocused vector vortex beam of metallic granary-shaped nanotip with spin-dependent dielectric helical cone.

We present the combined configuration of dielectric helical cone and metallic granary-shaped nanotip to produce three -dimensional vector vortex nanofocused optical field. The intensity and phase of the electric fields, and Povnting vector of the optical field generated by the combined configuration with linearly polarized illumination are studied with three-dimensional finite difference time-domain method. The localized vector electric field near the apex of the metallic granary-shaped nanotip is strongly depended on the chirality of the dielectric helical cone and the bottom radius of the metallic granary-shaped nanotip. The localized vector electric field is wavelength selective with the maximum intensity enhancement up to 104 times and minimum size of about 900 nm2, and the maximum radial electric field rotates 67.0° along z axis. This indicates the vector vortex beam generated by the combined configuration can be applied in nanofabrication, nano-sensing and nano-manipulation.

Dexmedetomidine preconditioning attenuates global cerebral ischemic injury following asphyxial cardiac arrest.

BACKGROUND/AIMS: To investigate the protection effect of dexmedetomidine preconditioning on global cerebral ischemic injury following asphyxial cardiac arrest (CA) in rats. METHODS: Seventy-two rats were randomly assigned into three groups, sham group (no asphyxia), control group (asphyxia only), and dexmedetomidine preconditioned group (asphyxia + dexmedetomidine). Dexmedetomidine was administered 5 minutes before an 8 min of asphyxia. Rats were resuscitated by a standardized method. Blood O(2) and CO(2) partial pressures were, pH, base excess (BE), and blood glucose concentration measured before asphyxial CA and 1 h after resuscitation. Neurological deficit score (NDS) was measured at 12, 24, 48, and 72 h after CA. Histopathologic changes in the hippocampal region were observed by H&E staining and histopathologic damage score. Ultrastructural morphology was observed by transmission electron microscopy. HIF-1 and VEGF expression were measured by immunostaining of serial sections obtained from brain tissue. RESULTS: Asphyxial CA -induced global cerebral ischemic decreased PaO(2), pH, BE and increased PaCO(2), blood glucose. Dexmedetomidine preconditioning improved neurologic outcome, which was associated with reduction in histopathologic injury measured by H&E staining, the histopathologic damage score and electron microscopy. Dexmedetomidine preconditioning also elevated HIF-1α and VEGF expression after global cerebral ischemia following asphyxial CA. CONCLUSION: Dexmedetomidine preconditioning protected against cerebral ischemic injury and was associated with upregulation of HIF-1α and VEGF expression.

[The correlation study on syndrome differentiation of rheumatoid arthritis and joint high frequency ultrasound performance].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Fast clinical molecular diagnosis of hyperphenylalaninemia using next-generation sequencing-based on a custom AmpliSeq™ panel and Ion Torrent PGM sequencing.

Hyperphenylalaninemia (HPA) can be classified into phenylketonuria (PKU) and tetrahydrobiopterin deficiency (BH4D), according to the defect of enzyme activity, both of which vary substantially in severity, treatment, and prognosis of the disease. To set up a fast and comprehensive assay in order to achieve early etiological diagnosis and differential diagnosis for children with HPA, we designed a custom AmpliSeq™ panel for the sequencing of coding DNA sequence (CDS), flanking introns, 5' untranslated region (UTR) and 3' UTR from five HPA-causing genes (PAH, PTS, QDPR, GCH1, and PCBD1) using the Ion Torrent Personal Genome Machine (PGM) Sequencer. A standard group of 15 samples with previously known DNA sequences and a test group of 37 HPA patients with unknown mutations were used for assay validation and application, respectively. All variations were confirmed by Sanger sequencing. In the standard group, all the known mutations were detected and were consistent with the results of previous Sanger sequencing. In the test group, we identified mutations in 71 of 74 alleles, with a mutation detection rate of 95.9%. We also found a frame shift deletion p.Ile25Metfs*13 in PAH that was previously unreported. In addition, 1 of 37 in the test group was inconsistent with either the molecular diagnosis or clinical diagnosis by traditional differential methods. In conclusion, our comprehensive assay based on a custom AmpliSeq™ panel and Ion Torrent PGM sequencing has wider coverage, higher throughput, is much faster, and more efficient when compared with the traditional molecular detection method for HPA patients, which could meet the medical need for individualized diagnosis and treatment.

Rs2200733 and rs10033464 on chromosome 4q25 confer risk of cardioembolic stroke: an updated meta-analysis.

A recent genome-wide association study elucidated that 4q25 was implicated in ischemic stroke, but subsequent studies showed inconsistent results. In order to get coincident conclusion, we investigated two SNPs (rs2200733, rs10033464) on chromosome 4q25 in 1,388 stroke patients and 1,629 controls from Chinese Han population and then performed a meta-analysis. Although we failed to detect any association between 4q25 and stroke in our case-control study, meta-analysis revealed that rs2200733 showed association with overall stroke (OR 1.18, 95 % CI 1.08-1.27), but not for rs10033464. Subsequently subgroup analysis indicated that both rs2200733 and rs10033464 conferred increased risk for cardioembolic stroke (CE stroke) (for rs2200733, OR 1.38, 95 % CI 1.26-1.51; for rs10033464, OR 1.14, 95 % CI 1.02-1.26), while rs2200733 was marginal associated with non-CE stroke (OR 1.09, 95 % CI 1.02-1.16). our results demonstrated that two SNPs (rs2200733 and rs1003346) on chromosome 4q25 were limited to the stroke of cardioembolic etiology. To confirm this conclusion, well-designed studies with larger sample size involving case-control populations with homogeneous ancestry warrant to be conducted in the future.

[Detection of homozygous deletions in spinal muscular atrophy with genomic DNA sequencing].

OBJECTIVE: 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). METHODS: 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. RESULTS: 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. CONCLUSION: Genomic DNA sequencing is a rapid, accurate and economic method for the diagnosis of homozygous deletion of SMA.

GADD45α alleviates the CDDP resistance of SK-OV3/cddp cells via redox-mediated DNA damage.

Epithelial ovarian cancer has the highest mortality rate of all malignant ovarian cancer types. Great progress has been made in the treatment of ovarian cancer in recent years. However, drug resistance has led to a low level of 5-year survival rate of epithelial ovarian cancer, and the molecular mechanism of which remains unknown. The aim of the present study was to identify the role of redox status in the cisplatin (CDDP) resistance of ovarian cancer. CDDP-resistant SK-OV3 (SK-OV3/cddp) cells were prepared and their reactive oxygen species and glutathione levels were investigated. The effects of hydrogen peroxide on the CDDP sensitivity of the SK-OV3/cddp cells and their expression levels of the redox-associated protein growth arrest and DNA damage 45a (GADD45α) were also investigated. In addition, the impact of GADD45α overexpression on cell viability was evaluated in vitro and in vivo, and the levels of Ser-139 phosphorylated H2A histone family member X (γ-H2AX), which is associated with DNA damage, were detected. The results suggested that redox status affected the drug resistance of the ovarian cancer cells by increasing the expression of GADD45α. The overexpression of GADD45α reversed the CDDP resistance of the SK-OV3/cddp cells and increased the level of γ-H2AX. In conclusion, GADD45α alleviated the CDDP resistance of SK-OV3/cddp cells via the induction of redox-mediated DNA damage.

[Analysis of clinical phenotype in 42 nuclear pedigrees carrying mitochondrial DNA A3243G mutation].

OBJECTIVE: A3243G mutation in mitochondrial DNA is the most common pathogenic point mutation causing a variety of phenotypes. The clinical phenotype and the relationship between the clinical phenotype and the ratio of A3243G mutation were studied in the members from nuclear families carrying A3243G mutation. METHODS: A total of 42 families carrying A3243G mutation were recruited and their clinical symptoms, laboratory results and the ratio of A3243G analyzed. RESULT: (1) In probands, myopathy, seizure, hirsutism, headache, cognitive impairment, weight loss and short stature were the most common clinical features. They tended to occur simultaneously. Lactic acid, pyruvate and MRI were abnormal in most probands; (2) most carriers had a normal phenotype. Myopathy, weight loss and short stature were their most common clinical features; (3) the ratio of A3243G mutation in urine was higher than that in blood in probands (t = -15.06, P < 0.001). And the ratio of A3243G mutation in urine was higher than that in blood in their mothers (z = -6.241, P < 0.001); (4) the ratio of A3243G mutation in probands was 2-fold higher than that in their mothers in both blood and urine. CONCLUSION: The phenotype of patients carrying A3243G mutation is varied. The clinical symptoms and laboratory results of probands are worse than those of mothers. It is probably due to a higher mutation ratio of m.3243A>G in their tissues.

Diagnosis of Spinal Muscular Atrophy: A Simple Method for Quantifying the Relative Amount of Survival Motor Neuron Gene 1/2 Using Sanger DNA Sequencing.

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.

Flavonoid biosynthesis controls fiber color in naturally colored cotton.

The existence of only natural brown and green cotton fibers (BCF and GCF, respectively), as well as poor fiber quality, limits the use of naturally colored cotton (Gossypium hirsutum L.). A better understanding of fiber pigment regulation is needed to surmount these obstacles. In this work, transcriptome analysis and quantitative reverse transcription PCR revealed that 13 and 9 phenylpropanoid (metabolic) pathway genes were enriched during pigment synthesis, while the differential expression of phenylpropanoid (metabolic) and flavonoid metabolic pathway genes occurred among BCF, GCF, and white cotton fibers (WCF). Silencing the chalcone flavanone isomerase gene in a BCF line resulted in three fiber phenotypes among offspring of the RNAi lines: BCF, almost WCF, and GCF. The lines with almost WCF suppressed chalcone flavanone isomerase, while the lines with GCF highly expressed the glucosyl transferase (3GT) gene. Overexpression of the Gh3GT or Arabidopsis thaliana 3GT gene in BCF lines resulted in GCF. Additionally, the phenylpropanoid and flavonoid metabolites of BCF and GCF were significantly higher than those of WCF as assessed by a metabolomics analysis. Thus, the flavonoid biosynthetic pathway controls both brown and green pigmentation processes. Like natural colored fibers, the transgenic colored fibers were weaker and shorter than WCF. This study shows the potential of flavonoid pathway modifications to alter cotton fibers' color and quality.

p.Val19Glyfs*21 and p.Leu228* variants in the survival of motor neuron 1 trigger nonsense-mediated mRNA decay causing the SMN1 PTC+ transcripts degradation.

Spinal Muscular Atrophy (SMA) results from loss-of-function mutations in the survival of motor neuron 1 (SMN1) gene. Our previous research showed that 40% of variants were nonsense or frameshift variants and SMN1 mRNA levels in the patients carrying these variants were significantly decreased. Here we selected one rare variant (p.Val19Glyfs*21) and one common variant (p.Leu228*) to explore the degradation mechanism of mutant transcripts. The levels of full-length (FL)-SMN1 transcripts and SMN protein in the cell lines from the patients with these variants were both significantly reduced (p<0.01). Treatment with two translation inhibitors (puromycin and Cycloheximide (CHX)) markedly increased the levels of FL-SMN1 transcripts with premature translation termination codons (PTCs) (p<0.01) and showed time-dependent (10h>5.5h) but not dose-dependent effects. Moreover, the knockdown of UPF1, a key factor in nonsense-mediated mRNA decay (NMD) by lentivirus, led to a 3.1-fold increase (p<0.01) in FL-SMN1 transcript levels in patient fibroblasts. Our research provides evidence that these two PTC-generating variants (p.Val19Glyfs*21 and p.Leu228*) can trigger NMD, causing rapid degradation of SMN1 transcripts thereby resulting in SMN protein deficiency. These two variants are highly pathogenic and are associated with more severe SMA phenotypes. Varying NMD efficiency after treatment with puromycin and CHX in different cell types was also observed.

Role of Diffusion-weighted and Contrast-enhanced Magnetic Resonance Imaging in Differentiating Activity of Ankylosing Spondylitis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

A rare variant (c.863G>T) in exon 7 of SMN1 disrupts mRNA splicing and is responsible for spinal muscular atrophy.

Proximal spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or mutation of SMN1 (survival motor neuron 1). SMN exon 7 splicing is regulated by a number of exonic and intronic regulatory sequences and the trans-factors that bind them. Variants located in or near these regulated regions should be evaluated to determine their effect on splicing. We identified the rare variant c.863G>T (r.835_*3del, p.Gly279Glufs*5) in exon 7 of SMN1 in three patients affected with type I or type II SMA. Most of the SMN1 transcripts exhibited complete loss of exon 7 in vivo. The ex vivo splicing assay demonstrated that the variant disrupts inclusion of exon 7 (~85%) in the SMN1 mRNA; replacement with various bases yielded a variety of splicing effects in SMN1 and SMN2 pre-mRNA. The c.863G>T (r.835_*3del, p.Gly279Glufs*5) variant is located in a region that includes binding sites for multiple splicing factors including Tra2ß1. Thus, the variant disrupts Tra2ß1 binding, but does not affect binding of hnRNP A1. These findings demonstrate how rare variants influence pre-mRNA splicing of SMN and reveal the functional influence of c.863G>T (r.835_*3del, p.Gly279Glufs*5) variant in patients with SMA.

Association between SMN2 methylation and disease severity in Chinese children with spinal muscular atrophy.

The homozygous loss of the survival motor neuron 1 (SMN1) gene is the primary cause of spinal muscular atrophy (SMA), a neuromuscular degenerative disease. A genetically similar gene, SMN2, which is not functionally equivalent in all SMA patients, modifies the clinical SMA phenotypes. We analyzed the methylation levels of 4 CpG islands (CGIs) in SMN2 in 35 Chinese children with SMA by MassARRAY. We found that three CpG units located in CGI 1 (nucleotides (nt) -871, -735) and CGI 4 (nt +999) are significantly hypomethylated in SMA type III compared with type I or II children after receiving Bonferroni correction. In addition to the differentially methylated CpG unit of nt -871, the methylation level of the nt -290/-288/-285 unit was negatively correlated with the expression of SMN2 full-length transcripts (SMN2-fl). In addition, the methylation level at nt +938 was inversely proportional to the ratio of SMN2-fl and lacking exon 7 transcripts (SMN2-Δ7, fl/Δ7), and was not associated with the SMN2 transcript levels. Thus, we can conclude that SMN2 methylation may regulate the SMA disease phenotype by modulating its transcription.

Mutation Spectrum of the Survival of Motor Neuron 1 and Functional Analysis of Variants in Chinese Spinal Muscular Atrophy.

Proximal spinal muscular atrophy (SMA) is a common fatal autosomal recessive disorder caused by deletion or mutation of the survival of motor neuron 1 (SMN1). Here, we studied SMA molecular pathology in 653 Chinese patients and found approximately 88.2% with homozygous SMN1 exon 7 deletion and 6.3% with heterozygous exon 7 loss using multiplex ligation-dependent probe amplification. SMN1 variants were detected in 34 patients with heterozygous SMN1 loss by clone sequencing. In 27 of them, 15 variants were identified: five were unreported novel variants [c.-7_9del(p.0), p.Tyr109Cys, p.Ile249Tyrfs*16, p.Tyr272Trpfs*35, and c.835-5T>G], five were previously found only in Chinese patients (p.Ser8Lysfs*23, p.Gln14*, p.Val19Glyfs*21, p.Leu228*, and p.Tyr277Cys), and five were reported in other populations [p.Ala2Gly, p.Gln15*, p.Glu134Lys, p.Ser230Leu, and c.863G>T (r.835_*3del, p.Gly279Glufs*5)]. Variants p.Ser8Lysfs*23 and p.Leu228* were the most common in Chinese SMA. Five variants (p.Ser8Lysfs*23, p.Gln14*, p.Gln15*, p.Val19Glyfs*21, and p.Leu228*) resulted in premature stop codons, likely causing SMN1 mRNA nonsense-mediated decay. The novel variant c.-7_9del (p.0) caused deletion of the translation start codon (AUG), resulting in full-length SMN protein loss. The novel variant c.835-5T>G, located in a splice site, resulted in 90% exon 7 skipping. Our study could facilitate early diagnosis for SMA patients in mutation detection and revealed the specific mutation spectrum of SMN1 in Chinese SMA and high genetic heterogeneity in subtle variants observed between patients from China and Caucasians.

Are polymorphisms of N-acetyltransferase genes susceptible to primary liver cancer in Luoyang, China?

AIM: To identify whether the polymorphisms of the N-acetyltransferase (NAT) genes are susceptible to primary liver cancer (PLC) in Luoyang, a PLC low-incidence area of China. METHODS: The NAT1 and NAT2 genotypes of 96 PLC cases and 173 controls were determined by PCR-RFLP. Both interaction between NAT1 or NAT2 and environmental risk factors were analyzed based on case control study. RESULTS: Compared to the control group, the frequencies of alleles NAT1*3, NAT1*4, NAT1*10, NAT1*14B and alleles NAT2*4, NAT2*6, NAT2*7 in PLC group showed no statistically significant difference (chi(2) = 2.61 and 4.16, respectively, both P>0.05). The frequencies of NAT1 genotypes NAT1*3/*3, NAT1*3/*4, NAT1*3/*10, NAT1*3/*14B, NAT1*4/*4, NAT1*4/*10, NAT1*4/*14B, NAT1*10/*10, NAT1*10/*14B, and NAT2 genotypes NAT2*4/*4, NAT2*4/*6, NAT2*4/*7, NAT2*6/*6, NAT2*6/*7 and NAT2*7/*7 also had no statistically significant difference between the two groups (chi(2) = 11.86 and 2.94 respectively both, P>0.05). Neither the frequencies of rapid and slow NAT1 acetylators nor the frequencies of rapid and slow NAT2 acetylators were significantly different between the two groups (chi(2) = 0.598 and 0.44, respectively, both P>0.05). The interaction between NAT1*10 and occupational exposures was found significant with an odds ratio of 3.40 (chi(2) = 8.42, P = 0.004, OR 95%CI:1.03-11.22). But no interaction was found between NAT2 and any environmental risk factors. CONCLUSION: The polymorphisms of NAT1 and NAT2 are not susceptible to PLC in Luoyang. Allele NAT1*10 interacts with occupational exposures.

A novel large deletion mutation of FERMT1 gene in a Chinese patient with Kindler syndrome.

Kindler syndrome (KS; OMIM 173650) is a rare autosomal recessive skin disorder, which results in symptoms including blistering, epidermal atrophy, increased risk of cancer, and poor wound healing. The majority of mutations of the disease-determining gene (FERMT1 gene) are single nucleotide substitutions, including missense mutations, nonsense mutations, etc. Large deletion mutations are seldom reported. To determine the mutation in the FERMT1 gene associated with a 7-year-old Chinese patient who presented clinical manifestation of KS, we performed direct sequencing of all the exons of FERMT1 gene. For the exons 2-6 without amplicons, we analyzed the copy numbers using quantitative real-time polymerase chain reaction (qRT-PCR) with specific primers. The deletion breakpoints were sublocalized and the range of deletion was confirmed by PCR and direct sequencing. In this study, we identified a new 17-kb deletion mutation spanning the introns 1-6 of FERMT1 gene in a Chinese patient with severe KS phenotypes. Her parents were carriers of the same mutation. Our study reported a newly identified large deletion mutation of FERMT1 gene involved in KS, which further enriched the mutation spectrum of the FERMT1 gene.