Oleic acid induces A7r5 cell proliferation and migration associated with increased expression of HGF and p‑p38

The phenotypes and mechanisms underlying the proliferation and migration of vascular smooth muscle cells (VSMCs) induced by oleic acid (OA) are not completely understood. Therefore, the aim of the present study was to further elucidate the effects of OA on the proliferation and migration of VSMCs. Using A7r5 cells, the hepatocyte growth factor (HGF) inhibitor PHA665752 and the p38 MAPK inhibitor SB203580 were utilized, and Cell Counting Kit-8 (CCK-8) assays, Transwell assays, flow cytometry, ELISAs, western blotting and reverse transcription-quantitative PCR (RT-qPCR) were conducted to assess the effects of OA. CCK-8 assays indicated that OA promoted (at 5 and 50 µmol/l) or inhibited (at 800 µmol/l) A7r5 cell proliferation in a time- and concentration-dependent manner (P<0.05). Transwell assays revealed that OA also promoted (at 50 µmol/l) or inhibited (at 800 µmol/l) A7r5 cell migration (P<0.05). Moreover, cell-cycle analysis identified that 50 µmol/l OA reduced the cellular population in the G₀/G₁ phase and enhanced the cellular population in the S phase (P<0.05), whereas 800 µmol/l OA increased the cell number in the G₀/G₁ phase and decreased the cell number in the S phase (P<0.05). In addition, OA promoted (at 50 µmol/l) or inhibited (at 800 µmol/l) the expression level of HGF in A7r5 cells, as demonstrated via ELISA, western blotting and RT-qPCR analyses (P<0.05). It was also found that OA promoted (at 50 µmol/l) or inhibited (at 800 µmol/l) the expression level of phosphorylated (p)-p38 in A7r5 cells, as indicated by western blotting (P<0.05). Furthermore, the cell proliferation, migration and HGF expression induced by OA (50 µmol/l) were mitigated by treatment with PHA665752 (0.1 µmol/l) (P<0.05), and the cell proliferation, migration and p-p38 expression induced by OA (50 µmol/l) were mitigated by SB203580 (2 µmol/l) (P<0.05). Thus, the results suggested that OA served a role in the proliferation and migration of VSMCs via HGF and the p38 MAPK pathway. Moreover, the proliferation and migration of VSMCs induced by OA was associated with increased expression levels of HGF and p-p38. Taken together, OA, HGF and p38 MAPK may be potential therapeutic targets for the treatment of atherosclerosis.

Heart Rate and Heart Rate Difference Predicted the Efficacy of Metoprolol on Postural Tachycardia Syndrome in Children and Adolescents

OBJECTIVE

To evaluate the ability of heart rate (HR) and HR difference during head-up tilt test (HUTT) and to predict clinical improvement related to metoprolol treatment in children and adolescents with postural tachycardia syndrome (POTS).

STUDY DESIGN

This was a retrospective cohort study. A total of 53 subjects (27 male, aged 6-12 years old, mean age 11.79 ± 1.50 years old) with POTS treated with metoprolol were involved from July 2012 to September 2019. In total, 52 subjects who underwent health examination during the same period were matched as the control group. Subjects in both groups underwent HUTT. The HR distance between 5 minutes and 0 minutes (HR difference 5) and between 10 minutes and 0 minutes (HR difference 10) during HUTT was calculated.

RESULTS

The POTS group was significantly greater than the control group in HR 5, HR 10, HR difference 5, and HR difference 10 (P < .01). There was no statistical difference in HR 0 between the 2 groups (P > .05). In total, 53 subjects with POTS were followed up for 96.0 (IQR, 40.5, 134.5) days during treatment with metoprolol. HUTT results demonstrated that 58.49% of subjects with POTS had a response and symptom scores were reduced after intervention. HR and HR difference were useful in predicting the efficacy of metoprolol on POTS. When HR 5, HR 10, HR difference 5, and HR difference 10, respectively, were ≥110, 112, 34, and 37 beats/min, the sensitivity and specificity were 82.50% and 69.23%, 84.62% and 69.70%, 85.29% and 89.47%, and 97.56% and 64.86%, respectively.

CONCLUSIONS

HR and HR difference are helpful to predict the efficacy of metoprolol on POTS in children and adolescents.

Effect of Intra-wound Vancomycin for Spinal Surgery: A Systematic Review and Meta-analysis

Intra-site prophylactic vancomycin in spine surgery is an effective method of decreasing the incidence of postsurgical wound infection. However, there are differences in the prophylactic programs used for various spinal surgeries. Thus, this systematic review and meta-analysis aimed to evaluate the effectiveness of using intra-wound vancomycin during spinal surgery and to explore the effects of dose-dependence and the method of administration in a subgroup analysis. A total of 628 citations or studies were searched in PubMed, Ovid, Web of Science, and Google Scholar that were published before August 2016 with the terms "local vancomycin", "intra-wound vancomycin", "intraoperative vancomycin", "intra-site vancomycin", "topical vancomycin", "spine surgery", and "spinal surgery". Finally, 19 retrospective cohort studies and one prospective case study were eligible for inclusion in the systematic review and meta-analysis. The odds of developing postsurgical wound infection without prophylactic local vancomycin use were 2.83-fold higher than the odds of experiencing wound infection with the use of intra-wound vancomycin (95% confidence interval, 2.03-3.95; P = 0.083; I² = 32.2%). The subgroup analysis including the dosage and the method of administration, revealed different results compared to previous research. The value of I² in the 1-g group was 27.2%, which was much lower than in the 2-g group (I² = 57.6%). At the same time, the value of I² was 0.0% (P = 0.792, OR = 2.70) when vancomycin powder was directly sprinkled into all layers of the wound. However, there is high heterogenicity (I² = 60.0%, P = 0.007, OR = 2.83) when vancomycin powder is not exposed to the bone graft and instrumentation. There are differences found with the method of local application of vancomycin for reducing postoperative wounds and further studies are necessary, including investigations focusing on the dose-dependent effects during spinal or the topical pharmacokinetic and other orthopaedic surgeries.

急性胰腺炎与肝功能异常之间的"因-果"关系研究进展

急性胰腺炎(acute pancreatitis, AP)与肝功能异常之间的关系问题是一个全新的临床课题, 现有的研究结果暗示: AP易累及肝脏, 肝功能受损也可影响胰腺. AP与肝功能异常之间可能存在着一定的互为"因-果"的关系. 本文检索和分析了近十年来有关AP与肝功能异常之间关系的文献报道, 从AP与肝功能异常的概念、AP诱发的肝功能异常及其机制、肝功能异常诱发的胰腺炎及其机制、胰腺炎与肝功能损伤之间的相互关系及临床意义等方面进行了综述, 期望能够为对临床预防和治疗"AP"或"肝功能异常"提供新的思考, 并为探索"AP"或"肝功能异常"的病理机制提供新的研究方向.

The FOXO1 Gene-Obesity Interaction Increases the Risk of Type 2 Diabetes Mellitus in a Chinese Han Population

Here, we aimed to study the effect of the forkhead box O1-insulin receptor substrate 2 (FOXO1-IRS2) gene interaction and the FOXO1 and IRS2 genes-environment interaction for the risk of type 2 diabetes mellitus (T2DM) in a Chinese Han population. We genotyped 7 polymorphism sites of FOXO1 gene and IRS2 gene in 780 unrelated Chinese Han people (474 cases of T2DM, 306 cases of healthy control). The risk of T2DM in individuals with AA genotype for rs7986407 and CC genotype for rs4581585 in FOXO1 gene was 2.092 and 2.57 times higher than that with GG genotype (odds ratio [OR] = 2.092; 95% confidence interval [CI] = 1.178-3.731; P = 0.011) and TT genotype (OR = 2.571; 95% CI = 1.404-4.695; P = 0.002), respectively. The risk of T2DM in individuals with GG genotype for Gly1057Asp in IRS2 gene was 1.42 times higher than that with AA genotype (OR = 1.422; 95% CI = 1.037-1.949; P = 0.029). The other 4 single nucleotide polymorphisms (SNPs) had no significant association with T2DM (P > 0.05). Multifactor dimensionality reduction (MDR) analysis showed that the interaction between SNPs rs7986407 and rs4325426 in FOXO1 gene and waist was the best model confirmed by interaction analysis, closely associating with T2DM. There was an increased risk for T2DM in the case of non-obesity with genotype combined AA/CC, AA/AC or AG/AA for rs7986407 and rs4325426, and obesity with genotype AA for rs7986407 or AA for rs4325426 (OR = 3.976; 95% CI = 1.156-13.675; P value from sign test [P(sign)] = 0.025; P value from permutation test [P(perm)] = 0.000-0.001). Together, this study indicates an association of FOXO1 and IRS2 gene polymorphisms with T2DM in Chinese Han population, supporting FOXO1-obesity interaction as a key factor for the risk of T2DM.

Relationship between intestinal flora microenvironment and colorectal cancer

Intestinal flora is a hot research topic. Studies suggest that intestinal flora is associated with the development of metabolic diseases, autoimmune diseases, neurological disorders, cognitive and behavioral disorders, cancer and so on. In this paper, we retrieved and analyzed the literature published in the past ten years which studied the relationship between microbiota microenvironment and colorectal cancer. We discuss the definitions of intestinal flora, microbiota microenvironment and colorectal cancer, the composition of intestinal flora, imbalance of intestinal flora, correlation between microbiota microenvironment and colorectal cancer, and the pathophysiology of colorectal cancer associated with microbiota microenvironment, with an aim to reveal the role of intestinal flora microenvironment in the pathogenesis of colorectal cancer, and to provide ideas and clues for the development of new intestinal flora-targeted approaches for prevention and treatment of colorectal cancer.

Effects of T-type calcium channel blockers on renal function and aldosterone in patients with hypertension: a systematic review and meta-analysis

Background

High blood pressure can cause kidney damage, which can increase blood pressure, leading to a vicious cycle. It is not clear whether the protective effects of T-type calcium channel blockers (T-type CCBs) on renal function are better than those of L-type CCBs or renin-angiotensin system (RAS) antagonists in patients with hypertension.

Methods and Findings

PUBMED, MEDLINE, EMBASE, OVID, Web of Science, Cochrane, CNKI, MEDCH, VIP, and WANFANG databases were searched for clinical trials published in English or Chinese from January 1, 1990, to December 31, 2013. The weighted mean difference (WMD) and 95% confidence interval (CI) were calculated and reported. A total of 1494 reports were collected, of which 24 studies with 1,696 participants (including 809 reports comparing T-type CCBs versus L-type CCBs and 887 reports comparing T-type CCB versus RAS antagonists) met the inclusion criteria. Compared with L-type CCBs, T-type CCBs resulted in a significant decline in aldosterone (mean difference = −15.19, 95% CI −19.65–−10.72, p<1×10⁻⁵), proteinuria (mean difference = −0.73, 95% CI −0.88–−0.57, p<1×10⁻⁵), protein to creatinine ratio (mean difference = −0.22, 95% CI −0.41–−0.03, p = 0.02), and urinary albumin to creatinine ratio (mean difference = −55.38, 95% CI −86.67–−24.09, p = 0.0005); no significant difference was noted for systolic blood pressure (SBP) (p = 0.76) and diastolic blood pressure (DBP) (p = 0.16). The effects of T-type CCBs did not significantly differ from those of RAS antagonists for SBP (p = 0.98), DBP (p = 0.86), glomerular filtration rate (p = 0.93), albuminuria (p = 0.97), creatinine clearance rate (p = 0.24), and serum creatinine (p = 0.27) in patients with hypertension.

Conclusion

In a pooled analysis of data from 24 studies measuring the effects of T-type CCBs on renal function and aldosterone, the protective effects of T-type CCBs on renal function were enhanced compared with L-type CCBs but did not differ from RAS antagonists. Their protective effects on renal function were independent of blood pressure.

The effects of calcium channel blockers in the prevention of stroke in adults with hypertension: a meta-analysis of data from 273,543 participants in 31 randomized controlled trials

BACKGROUND

Hypertension is a major risk factor for the development of stroke. It is well known that lowering blood pressure decreases the risk of stroke in people with moderate to severe hypertension. However, the specific effects of calcium channel blockers (CCBs) against stroke in patients with hypertension as compared to no treatment and other antihypertensive drug classes are not known.

METHODS AND FINDINGS

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CCBs effect on stroke in patients with hypertension in studies of CCBs versus placebo, angiotensin-converting-enzyme inhibitors (ACEIs), β-adrenergic blockers, and diuretics. The PUBMED, MEDLINE, EMBASE, OVID, CNKI, MEDCH, and WANFANG databases were searched for trials published in English or Chinese during the period January 1, 1996 to July 31, 2012. A total of 177 reports were collected, among them 31 RCTs with 273,543 participants (including 130,466 experimental subjects and 143,077 controls) met the inclusion criteria. In these trials a total of 9,550 stroke events (4,145 in experimental group and 5,405 in control group) were reported. CCBs significantly decreased the incidence of stroke compared with placebo (OR = 0.68, 95% CI 0.61-0.75, p<1×10(-5)), β-adrenergic blockers combined with diuretics (OR = 0.89, 95% CI 0.83-0.95, p = 7×10(-5)) and β-adrenergic blockers (OR = 0.79, 95% CI 0.72-0.87, p<1×10(-5)), statistically significant difference was not found between CCBs and ACEIs (OR = 0.92, 95% CI 0.8-1.02, p = 0.12) or diuretics (OR = 0.95, 95% CI 0.84-1.07, p = 0.39).

CONCLUSION

In a pooled analysis of data of 31 RCTs measuring the effect of CCBs on stroke, CCBs reduced stroke more than placebo and β-adrenergic blockers, but were not different than ACEIs and diuretics. More head to head RCTs are warranted.

Association between schizophrenia and single nucleotide polymorphisms in lipoprotein lipase gene in a Han Chinese population

OBJECTIVE

Many studies have suggested that certain types of lipids such as phospholipids, fatty acids, and cholesterols are involved in the pathology of nervous system diseases. Lipoprotein lipase (LPL), as the key enzyme of triglyceride hydrolysis, is expressed in the brain regions functionally relevant to learning, memory, and other cognitive functions. In addition, both genome-wide linkage and association studies in schizophrenia have implicated the chromosome 8p22 region, in which the LPL gene is located. Therefore, LPL is an attractive candidate gene for schizophrenia and we tested this hypothesis in a case-control sample.

METHODS

In this study, we investigated allele and genotype frequencies distributions of nine single nucleotide polymorphisms (SNPs) within the LPL gene in Han Chinese patients with schizophrenia (n=319) and healthy controls (n=575).

RESULTS

Significant differences were detected between case and control groups in the frequencies of rs253 alleles [odds ratio (OR): 1.74; 95% confidence interval (CI): 1.43-2.11; P=3.21×10] and genotypes (OR: 3.08; 95%CI: 2.07-4.56; global P=7.88×10), respectively. Interestingly, this association was observed only in the male (P=5.87×10 for allele; P=1.79×10 for genotype) and not in the female samples (P>0.05). After correcting for multiple testing, the above association remains to be significant (Pc<1×10). These results suggest that rs253 C allele and CC genotype confer risk for schizophrenia in men.

CONCLUSION

Our study lends support to the potential role of lipid metabolism in schizophrenia and further investigations are warranted.

Association between type 2 diabetes and CDKN2A/B: a meta-analysis study

Cyclin-dependent kinase inhibitor-2A/B (CDKN2A/B) has been reported as a candidate gene of type 2 diabetes (T2D) based on its chromosomal position and its important role in β-cell function and regeneration. However, studies to date have reported inconsistent findings regarding the association between T2D and CDKN2A/B. To clarify this inconsistence, we conducted a meta-analysis based on alleles and genotypes prevalence of rs10811661 and rs564398 in CDKN2A/B. The PubMed, EMBASE, and Medline databases were systematically reviewed for studies published between January, 2006, and November, 2010. A total of 35 reports were collected, among of them only 16 studies (including 24,407 cases and 33,937 controls) match the inclusion criteria and were selected for the statistical test. In the meta-analysis of published data, our results suggest that the rs10811661 T allele (OR 1.28, 95% CI 1.21-1.36, P < 1 × 10(-5)) and TT genotype (OR 1.32, 95% CI 1.22-1.43, P < 1 × 10(-5)) of CDKN2A/B were associated with type 2 diabetes respectively, but rs564398 was not (for allele only: OR 0.96, 95% CI 0.88-1.05, P = 0.35). The association between rs10811661 T allele and T2D was observed both in Asia (P < 1 × 10(-4)) and Europe ethnicity groups (P = 0.002). This meta-analysis yielded evidence that rs10811661 of CDKN2A/B confers risk for T2D. Larger studies with mixed ethnicity subjects are required to validate our findings.

Genome-wide screening for risk loci of idiopathic recurrent miscarriage in a Han Chinese population: a pilot study

The etiology of recurrent miscarriage (RM) is extremely heterogeneous, including genetic, immunologic, anatomic, endocrinological, and infectious anomalies. About 50% of RM is unexplained or poorly understood, which is called idiopathic recurrent miscarriage (IRM). The primary aim of this study was to identify the genetic loci that might be susceptible to IRM. Forty-four Han Chinese patients with IRM during the first trimester of their pregnancies and 44 healthy sex- and ethnic-matched controls were enrolled in this study. A case-control and genome-wide study was performed and 430 polymorphic microsatellite markers were analyzed. Three loci, 6q27 (D6S446, P = .028), 9q33.1 (D9S1776, P = .037), and Xp22.11 (DXS1226, P = .008), significantly associated with IRM were found. This work identified 3 genetic regions that might harbor genes predisposed to IRM and provided new insights for future genetic and etiological study of IRM. Further study is required to confirm it.

The common biological basis for common complex diseases: evidence from lipoprotein lipase gene

The lipoprotein lipase (LPL) gene encodes a rate-limiting enzyme protein that has a key role in the hydrolysis of triglycerides. Hypertriglyceridemia, one widely prevalent syndrome of LPL deficiency and dysfunction, may be a risk factor in the development of dyslipidemia, type II diabetes (T2D), essential hypertension (EH), coronary heart disease (CHD) and Alzheimer's disease (AD). Findings from earlier studies indicate that LPL may have a role in the pathology of these diseases and therefore is a common or shared biological basis for these common complex diseases. To examine this hypothesis, we reviewed articles on the molecular structure, expression and function of the LPL gene, and its potential role in the etiology of diseases. Evidence from these studies indicate that LPL dysfunction is involved in dyslipidemia, T2D, EH, CHD and AD; and support the hypothesis that there is a common or shared biological basis for these common complex diseases.

Chitinase-3-like 1 (CHI3L1) gene and schizophrenia: genetic association and a potential functional mechanism

BACKGROUND

Gene expression data and association analyses in two Chinese samples implicate chitinase 3-like 1 (CHI3L1), a cellular survival gene, in schizophrenia susceptibility.

METHODS

We tested whether the association data are robust to replication in a Caucasian schizophrenia sample and performed a comprehensive investigation of common genetic variation at the locus.

RESULTS

In a sample of 375 case and 812 control subjects we identified significant association with the same risk allele at the promoter single nucleotide polymorphism (SNP) associated in the original study (rs10399805; p = .018) and with another SNP at intron 7 of CHI3L1 (rs2275351; p = .008). The rs10399805 SNP is located at position -247 and disrupts the C/EBP-AML-1 binding site in the gene promoter; the risk allele is predicted to increase CHI3L1 expression, as has been reported in several postmortem schizophrenia studies. Carriers of the risk variant presented with fewer positive symptoms and relatively spared cognitive performance compared with other schizophrenia patients.

CONCLUSIONS

These findings support a functional mechanism for involvement of CHI3L1 in schizophrenia susceptibility, possibly contributing to a less severe illness. The associated variants in this study are not well tagged by all Whole-Genome Association (WGA) platforms, suggesting additional genotyping may be necessary despite the imminent availability of WGA data from large SZ samples. Because CHI3L1 may be involved in transmission of stress-induced cellular responses, studies of interaction with known environmental risk factors may also be warranted.

A review of gene linkage, association and expression studies in autism and an assessment of convergent evidence

Autism is a neurodevelopmental disorder with high heritability and a likely complex genetic architecture. Much genetic evidence has accumulated in the last 20 years but no gene has been unequivocally identified as containing risk variants for autism. In this article we review the past and present literature on neuro-pathological, genetic linkage, genetic association, and gene expression studies in this disorder. We sought convergent evidence to support particular genes or chromosomal regions that might be likely to contain risk DNA variants. The convergent evidence from these studies supports the current hypotheses that there are multiple genetic loci predisposing to autism, and that genes involved in neurodevelopment are especially important for future genetic studies. Convergent evidence suggests the chromosome regions 7q21.2-q36.2, 16p12.1-p13.3, 6q14.3-q23.2, 2q24.1-q33.1, 17q11.1-q21.2, 1q21-q44 and 3q21.3-q29, are likely to contain risk genes for autism. Taken together with results from neuro-pathological studies, genes involved in brain development located at the above regions should be prioritized for future genetic research.

Polymorphisms in the TSHR (thyrotropin receptor) gene on chromosome 14q31 are not associated with mental retardation in the iodine-deficient areas of China

Mental retardation (MR) is one of the most frequent handicaps among children. Fetal iodine deficiency disorder (FIDD) is the commonest cause of preventable MR. However, not everyone in the iodine-deficient areas is affected and familial aggregation is common. This suggests that genetic factors may play an important role. Thyroid hormone (TH) plays an important role in fetal and early postnatal brain development. The thyroid-stimulating hormone (TSH, or thyrotropin) receptor (TSHR) is located on the surface of thyroid cells and binds TSH. It results in the production of thyroid hormones via the activation of adenylate cyclase and phospatidylinositol-dependent signaling pathways. Some researchers formulated the hypothesis that TSH receptor expression in the brain may be involved in local thyroid homeostasis through TSH stimulating the DIO2 activity. In the previous study, we have proposed that DIO2 may protect against FIDD in the iodine-deficient areas of China. The TSHR gene, which located on chromosome 14q31 is a potential candidate gene for susceptibility to FIDD. To investigate the potential genetic contribution of TSHR gene, we performed a case-control association study in Chinese Han population from the Qin-Ba mountain regions using four common SNPs in the gene (rs2284716, rs917986, rs2075173 and rs2075179). Pairwise linkage disequilibrium (LD) analysis showed that LD was observed between rs2284716 and rs917986 and between rs2075173 and rs2075179. Single-locus analysis found that all four SNPs in TSHR gene showed no association after correction for multiple testing. Haplotype analysis showed no significant differences in frequency for three sets of haplotypes based on the pariwise LD results. In conclusion, our association results suggest that TSHR gene is not a susceptibility gene for FIDD in the iodine-deficient areas of China.

An association between polymorphisms of the interleukin-10 gene promoter and schizophrenia in the Chinese population

Immunological abnormalities have been found to be associated with schizophrenia for decades. Cytokines are key proteins involved in the immune system activation. Interleukin-10 (IL-10), an important immunoregulatory cytokine, is located on chromosome 1q31-32, a region previously reported to be linked to schizophrenia in genetic studies. Thus, a study was carried out on the association between schizophrenia and three single nucleotide polymorphisms in the promoter region of IL-10 gene. Totally, 341 patients and 334 controls of Chinese descent were analyzed. Statistically significant differences were observed in both allelic and genotypic frequencies of the -592A/C polymorphism (Allele, chi(2)=4.43, df=1, P=0.032, odds ratio (OR)=1.26, 95% CI 1.02-1.56; Genotype, chi(2)=6.18, df=2, P=0.044) while the other two polymorphisms did not show such differences. The observed haplotype distributions revealed a significant association with schizophrenia (P=0.0008). These data suggest that the IL-10 gene may confer susceptibility to the development of schizophrenia in the Chinese population.

Positive association of the DIO2 (deiodinase type 2) gene with mental retardation in the iodine-deficient areas of China

BACKGROUND

Iodine deficiency is the commonest cause of preventable mental retardation (MR) worldwide. However, in iodine-deficient areas not everyone is affected and familial aggregation is common. This suggests that genetic factors may also contribute. Thyroid hormone (TH) plays an important role in fetal and early postnatal brain development. The pro-hormone T4 (3,3',5,5'-triiodothyronine) is converted in the brain to its active form, T3, or its inactive metabolite, reverse T3, mainly by the action of deiodinase type 2 (DIO2).

METHODS

To investigate the potential genetic contribution of the DIO2 gene, we performed a case-control association study using three common SNPs in the gene (rs225014, rs225012, and rs225010) that were in strong linkage disequilibrium with each other.

RESULTS

Single marker analysis showed a positive association of MR with rs225012 and rs225010. Particularly with rs255012 [corrected], CC [corrected] genotype frequency was significantly higher in MR cases than in controls (chi squared [corrected] = 9.18, p = 0.00246). When we compared the distributions of common haplotypes, we also found significant differences between mental retardation and controls in the haplotype combination of rs225012 and rs225010 (chi2 = 15.04, df 2, global p = 0.000549). This association remained significant after Bonferroni correction (p = 0.0016470).

CONCLUSION

We conclude that allelic variation in the DIO2 gene may affect the amount of T3 available and in an iodine-deficient environment may partly determine overall risk of MR.

[Genetic analysis of a Chinese pedigree with congenital synpolydactyly]

Syndactyly is a limb malformation that shows a characteristic manifestation in both hands and feet. This condition is inherited as an autosomal dominant trait with reduced penetrance. Clinical presentation, in general, is complete or partial webbing between 3rd and 4th fingers. Syndactyly type I, II and III were mapped to 2q34-36, 2q31-q32 and 6q21-23.2 respectively. Syndactyly type II is named as synpolydactyly (SPD). Expansion of a polyalanine tract in the HOXD13 gene is known to cause synpolydactyly. HOXD13 gene locates in the HoxD complex. Nine homologous genes (HOXD1, -D3, -D4, -D8, -D9, -D10, -D11, -D12, -D13) of HoxD complex locate on chromosome 2 in the order of HOXD1 to HOXD13, among which HOXD13 is closest to the centromere. Deletions and duplications in HoxD complex or its upstream regulator factors have been identified to cause hand heteroplasia and consequently lead to abnormity of finger number or abnormity of configuration. We performed linkage analysis in a kindred with autosomal dominant hereditary syndactyly. Tight linkage to markers on chromosome 2q31-q32 (maximum two-point lod score: 6.78 at recombination fraction theta = 0.00) was observed. Multipoint linkage analysis produced a maximum LOD score of 7.02. Haplotype construction and analysis of recombination events narrowed this locus to a 20.61 cM region between markers D2S2302 and D2S315. No mutation was found in the coding region, the intro-exon boundaries, or part of the promoter region of HOXD13. Our result demonstrates that synpolydactyly locus in the Chinese Han Population is in the region of chromosome 2q31-q32 but a different causal gene can be involved.