Smek1 deficiency exacerbates experimental autoimmune encephalomyelitis by activating proinflammatory microglia and suppressing the IDO1-AhR pathway.

BACKGROUND: Experimental autoimmune encephalomyelitis (EAE) is an animal disease model of multiple sclerosis (MS) that involves the immune system and central nervous system (CNS). However, it is unclear how genetic predispositions promote neuroinflammation in MS and EAE. Here, we investigated how partial loss-of-function of suppressor of MEK1 (SMEK1), a regulatory subunit of protein phosphatase 4, facilitates the onset of MS and EAE. METHODS: C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG35-55) to establish the EAE model. Clinical signs were recorded and pathogenesis was investigated after immunization. CNS tissues were analyzed by immunostaining, quantitative polymerase chain reaction (qPCR), western blot analysis, and enzyme-linked immunosorbent assay (ELISA). Single-cell analysis was carried out in the cortices and hippocampus. Splenic and lymph node cells were evaluated with flow cytometry, qPCR, and western blot analysis. RESULTS: Here, we showed that partial Smek1 deficiency caused more severe symptoms in the EAE model than in controls by activating myeloid cells and that Smek1 was required for maintaining immunosuppressive function by modulating the indoleamine 2,3-dioxygenase (IDO1)-aryl hydrocarbon receptor (AhR) pathway. Single-cell sequencing and an in vitro study showed that Smek1-deficient microglia and macrophages were preactivated at steady state. After MOG35-55 immunization, microglia and macrophages underwent hyperactivation and produced increased IL-1ß in Smek1-/+ mice at the peak stage. Moreover, dysfunction of the IDO1-AhR pathway resulted from the reduction of interferon γ (IFN-γ), enhanced antigen presentation ability, and inhibition of anti-inflammatory processes in Smek1-/+ EAE mice. CONCLUSIONS: The present study suggests a protective role of Smek1 in autoimmune demyelination pathogenesis via immune suppression and inflammation regulation in both the immune system and the central nervous system. Our findings provide an instructive basis for the roles of Smek1 in EAE and broaden the understanding of the genetic factors involved in the pathogenesis of autoimmune demyelination.

Cervical Spinal Involvement in a Chinese Pedigree With Pontine Autosomal Dominant Microangiopathy and Leukoencephalopathy Caused by a 3' Untranslated Region Mutation of COL4A1 Gene.

Background and Purpose- Pontine autosomal dominant microangiopathy and leukoencephalopathy, a recently defined subtype of cerebral small vessel disease, is associated with mutations in COL4A1 (collagen type IV alpha 1 chain) 3' untranslated region. We here describe a pontine autosomal dominant microangiopathy and leukoencephalopathy pedigree with COL4A1 mutation presenting both pontine and cervical spinal cord involvement. Methods- For the diagnostic purpose, brain and spinal magnetic resonance imaging scanning, skin biopsy, and whole-exome sequencing were performed on the patients in the pedigree. Suspected pathogenic variants were further confirmed by cosegregation analysis using Sanger sequencing in the family members. Results- We identified a mutation located at the binding site of miR-29 (microRNA-29) in 3' untranslated region of COL4A1(c.*32G>A). The pontine autosomal dominant microangiopathy and leukoencephalopathy patients in this pedigree carried this variant, whereas other healthy family members but one did not. Magnetic resonance imaging showed lesions in the pons, white matter, and cervical spinal cord. Skin biopsy revealed thickened basal lamina in vessels. Conclusions- For the first time, we reported cervical spinal involvement in pontine autosomal dominant microangiopathy and leukoencephalopathy and expanded the clinical spectrum of this disease.

Association of polymorphisms in SPARC and NLRP2 genes with rheumatoid arthritis in a Chinese Han population.

OBJECTIVES: To investigate the association of the polymorphisms in SPARC and NLRP2 with rheumatoid arthritis (RA) in a Chinese Han population. METHODS: Four single nucleotide polymorphisms (SNPs) covering SPARC and three SNPs covering NLRP2 were investigated in 624 Chinese Han RA patients and 1920 healthy controls. RESULTS: The A allele at SPARC rs3210714, SPARC rs11950384, NLRP2 rs2217659, and NLRP2 rs703468 were linked to reduced risk of RA (p = 0.0016, p = 0.0051, p < 0.0001, and p = 0.0033, respectively). Under the recessive model, the A/A genotype of rs3210714, rs11950384, rs2217659, and rs703468 were relevant with RA (p = 0.0071, p = 0.017, p < 0.0001 and p = 0.0066, respectively). Haplotype analysis identified the SPARC GGCG haplotype, AAAA haplotype were associated with the risk for RA (p < 0.0001 and p = 0.0015, respectively), while the risk of RA was lower for carriers of the GAAA haplotype (p < 0.0001), AACG haplotype (p < 0.0001), and the AGCG haplotype (p < 0.0001). The NLRP2 GG haplotype was a risk factor (p < 0.0001), while the GA haplotype and the AG haplotype were associated with lower risk of RA (p < 0.0001 and p = 0.0017, respectively). There was no significant difference between the RA patients and the controls in polymorphisms of rs7719521, rs1978707, and rs269913. CONCLUSION: This study indicates that polymorphisms in SPARC and NLRP2 are related to RA susceptibility in a Chinese Han population.

Diagnostic signatures and immune cell infiltration characteristics in anti-GABABR encephalitis.

PURPOSE: Anti-gamma-aminobutyric acid B receptor (GABABR) encephalitis is an uncommon form of autoimmune encephalitis associated with a poor prognosis and a high fatality rate. We aim to find diagnostic markers for anti- GABABR encephalitis as well as the effects of immune cell infiltration on this pathology. METHODS: For quantitative proteomic analysis, isobaric tags for relative and absolute quantitation were used in conjunction with LC-MS/MS analysis. To conduct functional correlation analyses, differentially expressed proteins (DEPs) were identified. Following that, we used bioinformatics analysis to screen for and determine the diagnostic signatures of anti- GABABR encephalitis. ROC curves were used to evaluate the diagnostic values. To assess the inflammatory status of anti- GABABR encephalitis, we used cell-type identification by estimating relative subsets of the RNA transcript (CIBERSORT) and explored the link between diagnostic markers and infiltrating immune cells. RESULTS: Overall, 108 robust DEPs (47 upregulated and 61 downregulated) were identified, of which 11 were immune related. The most impressively enriched pathways were complemented and coagulation cascades, actin cytoskeleton regulation, and cholesterol metabolism; GSEA revealed that the enriched pathways were considerably differentially connected to immune modulation. Eleven immune-related DEPs were chosen for further investigation. We developed a novel diagnostic model based on CSF1R and AZGP1 serum levels using ROC analysis (area under the ROC curve = 1). M1 macrophages and activated natural killer cells are likely to play a role in course of anti- GABABR encephalitis. CONCLUSION: We identified CSF1R and AZGP1 are possible anti-GABABR encephalitis diagnostic indicators, and immune cell infiltration may have a significant impact on the development and occurrence of anti- GABABR encephalitis.

Loss of Smek1 Induces Tauopathy and Triggers Neurodegeneration by Regulating Microtubule Stability.

Suppressor of Mek1 (Smek1) is a regulatory subunit of protein phosphatase 4. Genome-wide association studies have shown the protective effect of SMEK1 in Alzheimer's disease (AD). However, the physiological and pathological roles of Smek1 in AD and other tauopathies are largely unclear. Here, the role of Smek1 in preventing neurodegeneration is investigated in tauopathy. Smek1 is downregulated in the aged human brain. Through single-cell sequencing, a novel neuronal cluster is identified that possesses neurodegenerative characteristics in Smek1-/- mice. Smek1 deficiency caused markedly more severe motor and cognitive impairments in mice, as well as neuronal loss, gliosis, and tau hyperphosphorylation at major glycogen synthase kinase 3ß (Gsk3ß) sites. Protein-protein interaction analysis revealed that the Ran-binding domain (RanBD) in the N-terminus of Smek1 facilitated binding with kinesin family member 2A (Kif2a). Depletion of Smek1 resulted in cytoplasmic aggregation of Kif2a, axon outgrowth defects, and impaired mitochondrial axonal trafficking. Downregulation of Kif2a markedly attenuated tau hyperphosphorylation and axon outgrowth defects in shSmek1 cells. For the first time, this study demonstrates that Smek1 deficiency progressively induces neurodegeneration by exacerbating tau pathology and mitochondrial dysfunction in an age-dependent manner.

[Association of two SNPs in 3'UTR of ETS1 gene with systemic lupus erythematosus in a northern Chinese Han population].

OBJECTIVE: To assess the association between 2 single nucleotide polymorphisms (SNPs) of ETS1 gene and susceptibility to systemic lupus erythematosus (SLE) in a northern Chinese Han population. METHODS: Two SNPs within the ETS1 gene mapped to 11q23 were selected based on HapMap data. Genotyping was conducted with Taqman method in 231 patients with SLE and 474 healthy controls from Qilu Hospital, Shandong and analyzed with PLINK1.07 software. Haplotypes were analyzed with SHEsis software. RESULTS: A statistically significant difference was detected in the distribution of rs1128334 and rs4937333 genotypes between the two groups (all P< 0.01). For rs1128334, the frequency of the minor allele was 0.291 and 0.428 in controls and cases, respectively. For rs4937333, the minor allele frequency was 0.381 and 0.476 in controls and cases respectively. An A-C haplotype was found to be strongly associated with increased risk for SLE, while another haplotype G-C may reduce this risk. CONCLUSION: Our study has suggested that rs1128334 and rs4937333 are strongly associated with the risk for SLE in northern Chinese Han population.

Two single nucleotide polymorphisms in TSLP gene are associated with asthma susceptibility in Chinese Han population.

BACKGROUND: Asthma is a chronic inflammatory disease of the airway that is mediated by T-helper 2(TH2) cells. Thymic stromal lymphopoietin (TSLP) can aggravate asthmatic lung inflammation by activating dendritic cells (DCs) to promote TH2 differentiation. TSLP promoter polymorphisms are associated with susceptibility to bronchial asthma in Japanese population. We sought to determine whether single nucleotide polymorphisms (SNPs) in TSLP gene are associated with asthma in Chinese Han population. OBJECTIVE: To analyze the polymorphism of the two SNPs Rs2289276 and Rs2289278 in TSLP gene and to evaluate the association between the two SNPs and asthma susceptibility in Chinese Han population by using case-control study. METHODS: five hundred and thirty one asthmatic patients and 540 age-sex matched normal controls were collected and DNA were extracted from peripheral blood, then the genotypes of SNPs Rs2289276 and Rs2289278 in TSLP gene were detected with polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP), genotype and allele frequencies were calculated and analyzed with Chi-square test. RESULTS: Frequencies of CC/CT/TT genotypes at Rs2289276 site were 0.4706/0.4392/0.0902 in the asthmatic patients and 0.5604/0.3800/0.0595 in the healthy controls. Frequencies of CC/CG/GG genotypes at Rs2289278 site were 0.6502/0.2966/0.0532 in the asthmatic patients and 0.5795/0.3428/0.0777 in the healthy controls. The genotype and allele frequencies of the two SNPs in asthma patients were significantly different from those in the healthy controls. Rs2289278 C allele was correlated with decreased FEV(1): FVC (P ≤ .05). CONCLUSIONS: TSLP variants are significantly associated with bronchial asthma. TSLP might be a new therapeutic target molecule for asthma.

[Association study between TNFSF4 and coronary heart disease].

Previous studies suggest that TNFSF4 is a susceptibility gene of atherosclerosis. But case-control association analysis in Swedish population and German population provided inconsistent, even opposite results. In order to explore the relationship between this gene and coronary heart disease (CHD) in Chinese Han population, we collected 498 cases and 509 controls from Qilu hospital of Shandong University and analyzed the association between five single-nucleotide polymorphisms (SNPs) (rs1234314, rs45454293, rs3850641, rs1234313, and rs3861950) of TNFSF4 and CHD. On the basis of using traditional statistical analysis methods based on single SNP and haplotypes, we introduced principal component score-based logistic regression analysis to deal with the data. The results suggested that in Armitage trend test, only rs3861950 was significant, when used the Bonferroni correction, and all of the five SNPs were not statistically significant. In the logistic regression analysis which adjusts the confounding factors, all of the five SNPs were not statistically significant. In haplotype analysis, the frequencies of six haplotypes were significantly different in cases and controls (CTAGT (P=0.0006), CTAAC (P=0.0123), CCAGT (P=0.0004), GTGGT (P=0.0329), GCGAC (P<0.0001), and GCAAC (P=0.0173)). In principal component score-based logistic regression analysis, the first principal component has statistical significance (P=0.0236). These results indicate that TNFSF4 is a susceptibility gene of CHD in Chinese Han population.

Two single nucleotide polymorphisms in ALOX15 are associated with risk of coronary artery disease in a Chinese Han population.

Arachidonate 12/15-lipoxygenase (12/15-LOX) has been implicated in the pathogenesis of atherosclerosis, but with contradicting results. The aim of this study was to investigate the association of two polymorphisms in ALOX15 and the risk of coronary artery disease (CAD) in a Chinese Han population. A total of 519 unrelated CAD patients and 608 unrelated control subjects of the Chinese Han population were recruited in the case-control study. Two tagSNPs, rs7217186:T>C and rs2619112:G>A, were selected and genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The carriers of the C allele (the CC homozygote and the CT heterozygote) of rs7217186:T>C and the carriers of the A allele (the AA homozygote and the GA heterozygote) of rs2619112:G>A displayed elevated odds ratios (ORs) for CAD compared with the TT homozygotes and GG homozygotes, respectively, after adjusting for other potential confounders including age, sex, body mass index, systolic blood pressure, diastolic blood pressure, glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and smoking status (adjusted odds ratio [OR] = 3.2, 95% confidence interval [CI]: 1.335-7.665, P = 0.009 and adjusted OR = 3.5, 95% CI: 1.343-9.330, P = 0.011). In stratified analyses, after adjusting those aforementioned confounders, the CC and CT genotypes of rs7217186:T>C were associated with a greater risk of CAD in subjects <60 years (adjusted OR = 5.7, 95% CI: 1.557-21.097, P = 0.009) and in females (adjusted OR = 9.3, 95% CI: 1.048-82.213, P = 0.045). For rs2619112:G>A, subjects (<60 years) carrying the A allele had a greater risk of CAD than the GG homozygotes (adjusted OR = 4.9, 95% CI: 1.215-19.547, P = 0.025); the male carriers of A allele also had a greater risk (adjusted OR = 3.5, 95% CI: 1.136-11.006, P = 0.029). In summary, the present study shows that after adjustment for other confounding CAD factors, rs7217186:T>C and rs2619112:G>A of ALOX15 are associated with increased risk of CAD in this Chinese Han population.

[Association of the ABCG1 gene polymorphism with the susceptibility and severity of coronary atherosclerotic disease].

OBJECTIVE: To investigate the association of the ATP-binding cassette sub-family G member 1 (ABCG1) gene polymorphisms with coronary atherosclerotic disease (CAD) in Chinese Han population. METHODS: A population based case-control association study was carried out in 541 patients with CAD and 649 healthy controls from Chinese Han population. Two single nucleotide polymorphisms (SNPs) of the ABCG1 gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Logistic regression was used to compare the genotypic and allelic frequency difference. RESULTS: The frequency of allele C of rs225374 was significantly higher in the CAD patients than that in the healthy controls (OR=1.186, 95%CI: 1.009-1.394, P=0.039), while the difference was also significant in the male subgroup (OR=1.236, 95%CI: 1.014-1.506, P=0.036). A statistically higher frequency of rs1044317 allele A was found in the CAD patients in comparison to the healthy controls (OR=1.187, 95%CI: 1.009-1.397, P=0.039). In case-only association study, rs225374 showed significant association in the high Gensini score group compared with the low Gensini score group (OR=1.303, 95%CI: 1.024-1.657, P=0.031). CONCLUSION: The two SNPs of the ABCG1 gene might be associated with the susceptibility and severity of CAD in Chinese Han population.

[Association of rs2298212 polymorphism in OX40 gene with coronary atherosclerotic disease in Chinese Han population].

OBJECTIVE: To study the association of the OX40 gene rs2298212G/A polymorphism with coronary atherosclerotic disease (CAD) in Chinese Han population. METHODS: Five hundred and thirty six CAD patients and 544 age and ethnic matched controls of Chinese Han population were recruited from Qilu Hospital, Shandong University. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype the selected single nucleotide polymorphism. Distributions of genotypic and allelic frequencies were analyzed by Chi-square test. RESULTS: The distribution of genotypic and allelic frequencies have no significant differences between the CAD cases and controls(P> 0.05), even after adjusting for age, gender, body mass index, systolic blood pressure, diastolic blood pressure, glucose, total cholesterol, and triglyceride. However, when substratification analysis of the involved coronary artery vessels was performed, significant difference was found between single-vessel and triple-vessel (P= 0.02, OR = 1.56, 95% CI: 1.08-2.26) involvement. CONCLUSION: The rs2298212G/A polymorphism in OX40 gene may be associated with the severity of coronary atherosclerotic disease.

[Clinical investigation of a family with brachydactyly type A1 and the identification of the disease gene].

OBJECTIVE: To determine the inheritance mode and pathogenesis of a family with brachydactyly type A1 in Jining, Shandong province via clinical feature and disease gene analysis. METHODS: Family survey and clinical examinations were performed to determine the inheritance mode; microsatellite polymorphic markers and polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)were employed for linkage analysis and mutation screening respectively. RESULTS: The brachydactyly type of the family was type A1 (BDA1), and autosomal dominant inheritance. A missense mutation (G298A) of the indian hedgehog gene (IHH) was identified in the patients of this family. CONCLUSION: A missense mutation G298A of the IHH gene might be the molecular basis for the brachydactyly type A1 in this family from Shandong province.

The effect of ZnO nanoparticles on liver function in rats.

Zinc oxide (ZnO) is widely incorporated as a food additive in animal diets. In order to optimize the beneficial effects of ZnO and minimize any resultant environmental pollution, ZnO nanoparticles are often used for delivery of the zinc. However, the possible toxic effects of ZnO nanoparticles, including effects on cytochrome P450 (CYP450) enzymes, have not been evaluated. In this study, we investigated the effect of ZnO nanoparticles, in doses used in animal feeds, on CYP450 enzymes, liver and intestinal enzymes, liver and kidney histopathology, and hematologic indices in rats. We found that liver and kidney injury occurred when the concentrations of ZnO nanoparticles in feed were 300-600 mg/kg. Also, liver mRNA expression for constitutive androstane receptor was suppressed and mRNA expression for pregnane X receptor was induced when feed containing ZnO nanoparticles was given at a concentration of 600 mg/kg. Although the expression of mRNA for CYP 2C11 and 3A2 enzymes was induced by ZnO nanoparticles, the activities of CYP 2C11 and 3A2 were suppressed. While liver CYP 1A2 mRNA expression was suppressed, CYP 1A2 activity remained unchanged at all ZnO nanoparticle doses. Therefore, it has been concluded that ZnO nanoparticles, in the doses customarily added to animal feed, changed the indices of hematology and blood chemistry, altered the expression and activity of hepatic CYP enzymes, and induced pathological changes in liver and kidney tissues of rats. These findings suggest that greater attention needs to be paid to the toxic effects of ZnO nanoparticles in animal feed, with the possibility that the doses of ZnO should be reduced.

[Analysis on genetic polymorphism of 5 STR loci selected from X chromosome].

OBJECTIVE: To select short tandem repeats(STR) from X chromosome. METHODS: STR is a universal genetic marker that has changeable polymorphism and stable heredity in human genome. It is a specific DNA segment composed of 2-6 base pairs as its core sequence. It is an ideal DNA marker used in linkage analysis and gene mapping. In this study, 8 short tandem repeats were selected from two genomic clones on X chromosome by using BCM Search Launcher. Primers amplifying the STR loci were designed by using Primer 3.0 according to the unique sequence flanking the STRs. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE. RESULTS: Five of these STRs were polymorphic. Chi-square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium (P>0.05). CONCLUSION: Five polymorphic short tandem repeats have been identified on chromosome X and will be useful for linkage analysis and gene mapping.

Lipoprotein lipase gene Hind III polymorphism was associated with hemorrhagic stroke.

OBJECTIVE: To investigate the relevance between lipoprotein lipase (LPL) Hind III gene polymorphism and cerebral hemorrhage. METHODS: A case-control study was performed utilizing PCR-RFLP method and sequencing of amplified products to detect LPL Hind III gene polymorphism in 350 cases of hemorrhagic stroke (HS group) and 350 healthy subjects (control group). Blood lipids and glucose levels were also recorded for each attendant. RESULTS: In HS group, T and G allele frequencies were 90.8% and 9.2%, respectively; while those in the control group were 82.3% and 17.7%. In HS group, detection rate of the G allele frequency and GG genotype were significantly lower than those in the control group. In addition, TG, LDL-C, fasting blood glucose , systolic blood pressure , diastolic blood pressure were significantly higher in HS group (P<0.05, P<0.01). Compared with TG+GG genotype, TT genotype population show significantly higher triglycerides concentration (P<0.05). With adjustment for hypertension, high blood sugar, and age -related factors, multivariate logistic regression analysis showed that LPL Hind III G allele could be a protective factor (OR = 0.392, 95% CI: 0.191~0.805, P = 0.011). CONCLUSION: LPL Hind III gene polymorphism was relevant to hemorrhagic stroke. LPL Hind III G mutant allele could be a protective factor in the pathogenesis of cerebral hemorrhage.

[Characterization of genomic structure and mutation analysis of SMARCA1 gene in a Smith-Fineman-Myers syndrome family].

The study is to determine the genomic structure and the role of SMARCA1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member1, SMARCA1) in the etiology of Smith-Fineman-Myers syndrome (SFMS). By comparing the cDNA sequence of SMARCA1 with the genomic sequences, genomic structure of SMARCA1 was determined, and conformed by amplifying and sequencing the sequences of exons and splicing junction. The results show that the genomic sequence of SMARCA1 gene exceeds 71.7 kb in length, and contains 24 exons and 23 introns. All the exon/intron boundaries follow the GT-AG rule and are in good agreement with the exon/intron consensus sequence. The characterization of genomic structure of SMARCA1 gene allows us to detect disease-causing mutation within the gene and further study its biological function. The open reading frame of SMARCA1 was detected for mutation by PCR amplification and direct sequencing in affected males from SFMS family in Shandong China. The disease in SFMS family from Shandong is not caused by the mutation within open reading frame of SMARCA1 gene.

[Polymorphic loci and polymorphism analysis of short tandem repeats within XNP gene].

To select polymorphic short tandem repeat markers within X-linked nuclear protein (XNP) gene, genomic clones which contain XNP gene were recognized by homologous analysis with XNP cDNA. By comparing the cDNA with genomic DNA, non-exonic sequences were identified, and short tandem repeats were selected from non-exonic sequences by using BCM search Launcher. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE. Five short tandem repeats were identified from XNP gene, two of which were polymorphic. Four and 11 alleles were observed in Chinese population for XNPSTR1 and XNPSTR4, respectively. Heterozygosities were 47% for XNPSTR1 and 70% for XNPSTR4. XNPSTR1 and XNPSTR4 localized within 3' end and intron 10, respectively. Two polymorphic short tandem repeats have been identified within XNP gene and will be useful for linkage analysis and gene diagnosis of XNP gene.

[Fine mapping of Smith-Fineman-Myers syndrome and exclusion of GPC3, GPCR2 MST4 and GLUD2 as candidate genes].

OBJECTIVE: Smith-Fineman-Myers syndrome (SFMS) is an X-linked mental retardation syndrome. The authors had ascertained a large Chinese family with SFMS from Shandong and had mapped the disease locus to an interval of 19.8 Mb on Xq25 flanked by markers DXS8064 and DXS8050. Further investigation suggested that SFMS exhibited locus heterogeneity. In this study for facilitating the identification of the gene responsible for SFMS, the additional markers were analyzed to narrow down the candidate region, and four candidate genes (GPC3, MST4,GPCR2 and GLUD2) were chosen and screened for disease-causing mutation. METHODS: PCR and denaturing polyacrylamide gel electrophoresis were used to genotype 13 new polymorphic markers distributed within the candidate region. Mutation detection was accomplished by sequencing the exons and intron-exon junctions of the candidate genes. RESULTS: By analyzing 13 additional polymorphic markers, SFMS candidate region can be reduced to an interval of 10.18 Mb bounded by XSTR3 and XSTR4, and no disease-causing mutation was identified in the coding regions of four candidate genes. CONCLUSION: GPCR2 GPC3, MST4 and GLUD2 were excluded as pathogenic genes for SFMS. The refined SFMS locus will assist in the identification and characterization of other candidate genes for SFMS.

[Application of homozygosity mapping to the fine mapping of the osteoporosis-pseudoglioma syndrome locus].

OBJECTIVE: To evaluate the role of homozygosity mapping in the fine mapping of the genes responsible for the rare autosomal recessive diseases. METHODS: Polymerase chain reaction-single sequence length polymorphism was used to genotype the family members from 8 families with osteoporosis-pseudoglioma syndrome(OPS) for 14 polymorphic loci within candidate region. The OPS candidate region was narrowed by searching for homozygous region in affected. RESULTS: The OPS candidate region was narrowed to a 1 cM interval between D11S1296 and D11S4136. CONCLUSION: Homozygosity mapping is a powerful method for mapping and narrowing the candidate region of the genes responsible for the rare autosomal recessive diseases.