Assignment of the human connexin43 gene,GJA1, to chromosome 6q22.3

Summary Connexin43 is one of connexin proteins which make up the intercellular gap junctions. Targeted null mutation of the mouse connexin43 gene has been reported to result in a cardiac malformation. Moreover, single-base mutations of the human homolog (GJA1) were identified in patients with laterality defects of the chest and abdominal organs, suggesting that connexin43 contributes to the determination of laterality during organogenesis. We mappedGJA1 to 6q22.3 by fluorescencein situ hybridization, using a bacterial artificial chromosome (BAC) clone that covered almost the entireGJA1-cDNA, as a probe.     

Significant association of a single nucleotide polymorphism in the tumor necrosis factor-alpha (TNF-α) gene promoter with human narcolepsy

Narcolepsy is a sleep disorder in which multiple factors, including environmental and genetic factors, are involved. A genetic factor strongly associated with the disorder has been found in the human leukocyte antigen (HLA) class II region: the haplotype, DRB1*1501-DQB1*0602, predisposes to narcolepsy. No susceptibility genes other than the HLA-haplotype have been found. In this paper, we performed an association study of the tumor necrosis factor-alpha (TNF-alpha) gene located in the HLA class III region with human narcolepsy, in which we examined the known single-nucleotide polymorphisms (SNPs) in the promoter region in 49 narcoleptic patients, who were all positive for DRBI*1501, and 111 healthy control individuals. The results indicated that the frequency of the genotype at position -857 (-857SNP) was significantly different between the patients and controls, and the allele frequencies of 857SNP revealed that the frequency of -857T was significantly increased in the patients as compared with that in the controls (P=0.0068). In addition, haplotypes presumed from HLA-DRB1, -857SNP and HLA-B loci suggested that -857T was mainly associated with DRB1 alleles other than DRB1*1501: the significant increase in frequency of -857T in the patients was not caused by allelic association with DRB1*1501. Therefore, it is conceivable that the TNF-alpha with 857T was associated with narcolepsy independently of the strong association of DRB1*1501 with the disorder. Altogether, the data presented here lead us to propose that TNF-alpha could be a new susceptibility gene in human narcolepsy.     

Nogo-A: a useful marker for the diagnosis of oligodendroglioma and for identifying 1p19q codeletion

The differential diagnosis between oligodendrogliomas and other gliomas remains a critical issue. The aim of this study is to verify the diagnostic value of Olig-2, Nogo-A, and synaptophysin and their role in identifying 1p19q codeletion. A total of 168 cases of brain tumors were studied: 24 oligodendrogliomas, 23 anaplastic oligodendrogliomas, 2 oligoastrocytomas, 2 anaplastic oligoastrocytomas, 30 glioblastoma multiforme, 2 diffuse astrocytomas, 4 anaplastic astrocytomas, 10 pilocytic astrocytomas, 9 ependymomas, 12 anaplastic ependymomas, 10 central neurocytomas, 10 meningiomas, 10 choroid plexus papillomas, 10 dysembryoplastic neuroepithelial tumors, and 10 metastases. All cases were immunostained with Olig-2, Nogo-A, and synaptophysin. In 79 cases, the status of 1p/19q had already been assessed by fluorescence in situ hybridization. Thus, in selected cases, fluorescence in situ hybridization was repeated in areas with numerous Nogo-A-positive neoplastic cells. Nogo-A was positive in 18 (75%) of 24 oligodendrogliomas, 8 (80%) of 10 dysembryoplastic neuroepithelial tumors, 6 (20%) of 30 glioblastoma multiforme, and 2 (20%) of 10 pilocytic astrocytomas. Olig-2 stained 22 (91.6%) of 24 oligodendrogliomas and all dysembryoplastic neuroepithelial tumors but also 24 (80%) of 30 glioblastoma multiforme and 8 (80%) of 10 pilocytic astrocytomas. Finally, synaptophysin stained 13 (54.1%) of 24 oligodendrogliomas, 3 (10%) of 30 glioblastoma multiforme, 1 (10%) of 10 pilocytic astrocytomas, and all neurocytomas. Among the 79 tested cases, original fluorescence in situ hybridization showed 1p/19q codeletion in 12 (52.2%) of 23 oligodendrogliomas, 8 (38%) of 21 anaplastic oligodendrogliomas, and 1 (4%) of 25 glioblastoma multiforme. However, after carrying out the Nogo-A-driven fluorescence in situ hybridization, 1p/19q codeletion was observed in 8 additional cases. Nogo-A is more useful and specific than Olig-2 in differentiating oligodendrogliomas from other gliomas. Furthermore, using a Nogo-A-driven fluorescence in situ hybridization analysis, it is possible to identify a larger number of 1p19q codeletions in gliomas.     

Evidence for association with hepatocellular carcinoma at the PAPSS1 locus on chromosome 4q25 in a family-based study

A region on chromosome 4q25 has recently been highlighted as linked to hepatocellular carcinoma (HCC). In this study, we performed a family-based association analysis with 67 single-nucleotide polymorphisms (SNPs) to map this linkage region in 240 families with HCC, 212 (88.3%) of which were ascertained through hepatitis B virus surface antigen (HBsAg)-positive index cases. Individual SNP analysis with correction for multiple testing identified 10 SNPs in two correlated haplotype blocks, located in or around the 3′-phosphoadenosine 5′-phosphosulfate synthetase-1 (PAPSS1) gene (all P-values: <0.0075). Our linkage data and GIST (Genotype identity-by-descent sharing test) indicate that 6 of these 10 SNPs contributed to the linkage signal. The haplotype block of the strongest association with HCC extended from the intron 5 to the 3′-flanking region of PAPSS1; multiple consecutive three-SNP haplotypes in this region were significant. The most significant haplotype showed odd ratios of 3.41 (95% confidence interval (CI)=1.36–8.53) for homozygous individuals in a case-unaffected sibling analysis. This haplotype also revealed an association with elevated serum α-fetoprotein and with poor survival in familial cases and an independent series of HBsAg-positive cases with small tumor present at the time of hospital admission. These results implicate PAPSS1 as a candidate HCC-susceptibility gene in hepatitis B carriers.     

Clinical significance of chromosome 1p/19q loss of heterozygosity and Sox17 expression in oligodendrogliomas

Objective: To study chromosome 1p/19q loss of heterozygosity (LOH) and Sox17 protein expression in oligodendrogliomas and correlate this loss with clinicopathological features. Methods: This study included 100 cases of oligodendrogliomas at the First Affiliated Hospital of Xinjiang Medical University from 2003 to 2014. The cases included paraffin-embedded tissues from 50 low-grade oligodendrogliomas and 50 anaplastic oligodendrogliomas. Chromosome 1p/19q LOH was detected by fluorescence in situ hybridization (FISH) and Sox17 protein expression was analyzed by immunohistochemistry. Clinicopathological characteristics of the oligodendrogliomas were compared and prognosis analyzed using Cox regression and Kaplan-Meier analyses. Results: The LOH positivity rate of 1p/19q was 52% in 50 cases of low-grade oligodendrogliomas and 68% in 50 cases of anaplastic oligodendrogliomas (P = 0.102). The rates of Sox17 expression were significantly different in oligodendrogliomas (82%) and anaplastic oligodendrogliomas (62%, P = 0.026). Single factor analysis determined that 1p/19q LOH (P = 0.000), Sox17 protein expression (P = 0.000), location (P = 0.001), chemotherapy (P = 0.000), and radiation therapy (P = 0.001) were associated with oligodendroglioma patient prognosis. Cox multiple factors regression analysis determined that 1p/19q LOH and Sox17 expression were independent prognostic factors of oligodendrogliomas. Conclusion: In this study, oligodendroglioma patients with 1p/19q LOH and Sox17 protein expression had a better prognosis. Thus, analysis of 1p/19q LOH and Sox17 protein expression could significantly enhance diagnostic accuracy, guide treatment, and improve the prognosis.     

Variable phenotypes associated with 10q23 microdeletions involving the PTEN and BMPR1A genes

Infantile juvenile polyposis is a rare disease with severe gastrointestinal symptoms and a grave clinical course. Recently, 10q23 microdeletions involving the PTEN and BMPR1A genes were found in four patients with infantile juvenile polyposis. It was hypothesized that a combined and synergistic effect of the deletion of both genes would explain the condition. Subsequently, however, a patient with a larger 10q23 deletion including the same genes but with a mild clinical phenotype was identified. Here, we present four additional patients with 10q23 microdeletions involving the PTEN and BMPR1A genes. The sizes of the deletions were analyzed using single nucleotide polymorphism array analysis. All patients had macrocephaly, dysmorphic features, retardation and congenital abnormalities. One patient developed colorectal cancer. However, only one case had disease onset before 2 years of age and severe symptoms requiring colectomy. No clear correlation was found between ages at onset or severity of gastrointestinal symptoms and the sizes of the deletions. We conclude that patients with 10q23 microdeletions involving the PTEN and BMPR1A genes have variable clinical phenotypes, which cannot be explained merely by the deletion sizes. The phenotypes are not restricted to severe infantile juvenile polyposis but include childhood-onset cases with macrocephaly, retardation, mild gastrointestinal symptoms and possibly early-onset colorectal cancer.     

Interstitial deletion of chromosome 10, del(10) (q11.2q22.1) in a boy with developmental delay and multiple congenital anomalies

We describe a 4-year-old boy with an interstitial deletion of the long arm of chromosome 10:del(10) (q11.2q22.1). Frontal bossing, hypertelorism, bright blue iris color, up-slanting palpebral fissures, a flat nasal bridge, a broad nose, apparently low-set ears, micrognathia, deep philtrum, and hypotonia were noted neonatally. A murmur was noted at age 5½ months and surgical repair of subaortic stenosis was required at 4 years. At 4 years micrognathia was no longer evident, but the palate was high-arched. The pattern of abnormalities included postnatal-onset slow growth, short stature, mental retardation, and cardiac anomalies. © 1993 Wiley-Liss, Inc.     

10p末端三体致多发畸形的临床表型及遗传学分析

目的分析1例多发畸形患儿的遗传学原因,探讨其染色体变异与表型的相关性。方法应用常规G显带分析患儿外周血染色体核型,采用低覆盖度全基因组高通量测序技术(low-coverage massively parallel copy number variation sequencing,CNV-seq)进行DNA拷贝数变异分析,并通过荧光原位杂交对患儿及父母进行验证,以判断变异区域的结构变化和遗传学来源。结果G带检测患儿核型为46,XX,3pter+?。CNV-seq分析结果显示患儿10pl3pl5.3区存在约13.5 Mb重复(60466〜13556655)和3p26.3区存在636 kb微缺失(60064〜695821)0对患儿及父母进行FISH验证,明确患儿核型为46,XX,ish der(3)t(3;10)(10p+,3p dim),父母荧光原位杂交验证结果未见异常,提示患儿为新发变异。结论患儿的10pl3pl5.3重复与智力缺陷、生长迟缓、畸形表型、胃食管返流等临床表型相关。3p末端缺失涉及CHL1基因,该基因在大脑的构建和功能中起重要作用,可能同时协作影响患儿的智力发育。     

A novel promoter polymorphism in the gene encoding complement component 5 receptor 1 on chromosome 19q13.3 is not associated with asthma and atopy in three independent populations

BACKGROUND: The inflammatory functions of complement component 5 (C5) are mediated by its receptor, C5R1, which is expressed on bronchial, epithelial, vascular endothelial and smooth muscle cells. A susceptibility locus for murine allergen-induced airway hyper-responsiveness was identified in a region syntenic to human chromosome 19q13, where linkage to asthma has been demonstrated and where the gene encoding C5R1 is localized. OBJECTIVE: The aim of this study was to screen for novel polymorphisms in the C5R1 gene and to determine whether any identified polymorphisms are associated with asthma and/or atopy and whether they are functional. METHODS: Single-nucleotide polymorphism (SNP) detection in the gene encoding C5R1 was performed by direct sequencing. Genotyping was performed in three populations characterized for asthma and/or atopy: (1) 823 German children from The Multicenter Allergy Study; (2) 146 individuals from Tangier Island, Virginia, a Caucasian isolate; and (3) asthma case-parent trios selected from 134 families (N=783) in Barbados. Functional studies were performed to evaluate differences between the wild-type and the variant alleles. RESULTS: We identified a novel SNP in the promoter region of C5R1 at position -245 (T/C). Frequency of the -245C allele was similar in the German (31.5%) and Tangier Island (36.3%) populations, but higher in the Afro-Caribbean population (53.0%; P=0.0039 to <0.0001). We observed no significant associations between the -245 polymorphism and asthma or atopy phenotypes. Upon examination of the functional consequences of the -245T/C polymorphism, we did not observe any change in promoter activity. CONCLUSION: This new marker may provide a valuable tool to assess the risk for C5a-associated disorders, but it does not appear to be associated with asthma and/or atopy.     

Primary congenital glaucoma caused by the homozygous F261L CYP1B1 mutation and paternal isodisomy of chromosome 2

Primary congenital glaucoma (PCG), a rare, severe and blinding disease, usually results from mutations in the CYP1B1 gene located in chromosome 2p22.2. Uniparental isodisomy (UPID) is also a rare condition in which a diploid offspring carries two identical copies of a single parental chromosome. By DNA sequence analysis, we found that a proband (female newborn) affected by PCG was homozygous for the null‐allele F261L of the CYP1B1 gene. Her father was a heterozygous carrier for this mutation, and unexpectedly her mother carried only the G168D mutation in the heterozygous state. Segregation analysis of eight microsatellite markers which spanned the two arms of chromosome 2 was consistent with paternal isodisomy for this chromosome in the proband. To the best of our knowledge, this is the first reported case of UPID resulting in PCG and the fifth reported case of paternal UPID for chromosome 2. In addition, the absence of a clinical phenotype other than PCG confirms previous observations of there being no paternally imprinted genes in chromosome 2 that have major phenotypic effects. These results, along with previous reports, also suggest that UPID may play a relevant role in recessive diseases linked to chromosome 2.     

A de novo non-sense mutation in ZBTB18 in a patient with features of the 1q43q44 microdeletion syndrome

The phenotype of patients with a chromosome 1q43q44 microdeletion (OMIM; 612337) is characterized by intellectual disability with no or very limited speech, microcephaly, growth retardation, a recognizable facial phenotype, seizures, and agenesis of the corpus callosum. Comparison of patients with different microdeletions has previously identified ZBTB18 (ZNF238) as a candidate gene for the 1q43q44 microdeletion syndrome. Mutations in this gene have not yet been described. We performed exome sequencing in a patient with features of the 1q43q44 microdeletion syndrome that included short stature, microcephaly, global developmental delay, pronounced speech delay, and dysmorphic facial features. A single de novo non-sense mutation was detected, which was located in ZBTB18. This finding is consistent with an important role for haploinsufficiency of ZBTB18 in the phenotype of chromosome 1q43q44 microdeletions. The corpus callosum is abnormal in mice with a brain-specific knock-out of ZBTB18. Similarly, most (but not all) patients with the 1q43q44 microdeletion syndrome have agenesis or hypoplasia of the corpus callosum. In contrast, the patient with a ZBTB18 point mutation reported here had a structurally normal corpus callosum on brain MRI. Incomplete penetrance or haploinsufficiency of other genes from the critical region may explain the absence of corpus callosum agenesis in this patient with a ZBTB18 point mutation. The findings in this patient with a mutation in ZBTB18 will contribute to our understanding of the 1q43q44 microdeletion syndrome.     

中国北方人群14个短串联重复序列位点的遗传多态性分析

目的 分析中国北方汉族人群中染色体7p14—15区域内6个短串联重复序列(short tandem repeat，STR)位点和12q13区域内8个STR位点的遗传多态性。方法 采用荧光标记PCR扩增技术和毛细管电泳方法，对染色体7p14—15区域内D7S1808、D7S2250、D7S2251、D7S683、D7S656、D7S528位点和12q13区域内D12S1056、D12S1293、D12S83、D12S1655、D12S1662、D12S334、D12S137、D12S102位点在100名随机选取的无血缘关系的中国北方汉族人群中的遗传多态性进行分析。结果 在中国北方汉族人群中，染色体7p14-15区域的D7S1808、D7S2250、D7S2251、D7S683、D7S656和D7S528位点分别检测出7、8、7、4、6和5个等位基因，24、27、22、10、17和13种基因型，杂合度分别为86％、88％、83％、79％、85％和80％；染色体12q13区域的D12S1056、D12S1293、D12S83、D12S1655、D12S1662、D12S334、D12S137和D12S102位点分别检测出5、5、8、6、6、6、5和7个等位基因，15、15、29、17、17、19、13和24种基因型，杂合度分别为86％、84％、87％、82％、84％、85％、81％和89％。结论 染色体7p14—15区域的6个STR位点和12q13区域的8个STR位点基因频率分布符合Hardy—Weinberg平衡，并在中国北方汉族人群中呈现较好的遗传多态性。     

Developmental profile in a patient with monosomy 10q and dup(17p) associated with a peripheral neuropathy

We report on a patient with dup(17p) and monosomy (10q) resulting from a familial translocation. Manifestations typical of both syndromes were present. The overall development of this patient was better by comparison with similar reported cases of either anomaly. Our evaluation detected severe gross motor delay and signs of a demyelinating peripheral neuropathy. This patient is trisomic for the region of 17p which includes the peripheral myelin protein-22 (PMP-22) gene, known to be duplicated in Charcot-Marie-Tooth neuropathy type 1A (CMT1A). Our analysis in this patient suggests that trisomy for the PMP-22 gene led to the demyelinating neuropathy and contributed to his severe motor developmental delay. © 1996 Wiley-Liss, Inc.     

Two cases of interstitial deletion of the long arm of chromosome 1: del(1)(q21 → q25) and del(1)(q41 → q43)

Two unrelated children, one with a proximal interstitial deletion 1 (1(pter----q21: :q25----qter] and the other one with a distal interstitial deletion 1 (1(pter----q41: :q43----qter] are presented. The clinical features of the patient with a proximal deletion (q21-q25) correspond with those of eight earlier reported cases with a deletion 1q21/22/23----q25. The second patient with the distal interstitial deletion (q41-q43) is the first case published as far as we know. The clinical characteristics of the latter patient are compared with those of six cases with a terminal deletion 1q with at least one common band missing (1q42).     

Constitutive fragile sites 1p31, 3p14, 6q26, and 16q23 and their use as controls for false-negative results with the fragile(X)

Fragile(X) estimations in fragile(X)-mental retardation hemizygotes or heterozygotes can become falsely negative in stored blood (lymphocytes). This was shown in blood stored (before culture) at 4°C, room temperature (25°C), 37°C, and 39°C for 1–4 days. After storage, blood was cultured in Ham's F10-5% FC serum with 0.1 μM FUdR and scored for fra(X) and the constitutive fragile sites at 3p14 and 6q26. It was found that the proportion of cells expressing the fragile(X) and the 3p14 site varied inversely with the temperature and time of storage. In addition, 50 patients and controls were scored for the three latter sites after routine 72–96-hr culture in F 10–0.05 or 0.1 μM FUdR. The 3p14 site was detected in every individual tested in a mean ± S.D. of 11.3 ± 3.2% of cells (0.1 μM FUdR). It was found that this site was FUdR dose dependent whereas the 6q26 site was not. The 3p14 (but not the 6q26) site is therefore suitable as a control site for the FUdR effect. It is proposed that repeat studies are necessary when less then 4% 3p14 sites are present in specimens from males referred for fra(X) estimation. Other constitutive fragile sites (eg, 1p31 and 16q23) can also be used.     

Neonatal death in cousins with trisomy 10q and monosomy 4p due to a familial translocation

Two cousins with trisomy for a part of the long arm of chromosome 10 and monosomy for the distal portion of the short arm of chromosome 4 are reported. These infants had severe, neonatally lethal, multiple malformations. Certain of these malformations - including severe lower limb reductions, marked ophthalmologic anomalies and certain craniofacial features - are inconsistent with either a simple additive effect of the two component chromosomal anomalies, or chromosomal "epistasis" that would result in observing the phenotypic effect of only one of the chromosomal aberrations. Rather a synergistic effect of these two karyotypic anomalies has resulted in unique phenotypic features.     

ABCG1基因两个单核苷酸多态位点与冠状动脉粥样硬化性心脏病易感性及病情严重程度的相关性分析

目的 应用基于群体的病例-对照关联研究方法探讨ABCG1基因上的遗传多态性与冠状动脉粥样硬化性心脏病(简称冠心病)及病情严重程度的相关性.方法 在山东汉族人群中收集541例冠心病患者和649名正常对照,采用聚合酶链反应-限制性片段长度多态方法对ABCG1基因内两个单核甘酸多态位点进行基因分型,统计学分析.结果 rs225374等位基因C在病例组中的频率显著高于对照组(OR=1.186,95%CI:1.009～1.394,P=O.039),在男性病例组与对照组中的差异同样具有统计学意义(OR=1.236,95%CI:1.014～1.506,P=O.036).rs1044317等位基因A在病例组中的频率显著高于对照组(OR=1.187,95%CI:1.009～1.397,P=0.039).单独在病例组内的分析结果显示,rs225374等位基因C频率在高Gensini积分组中显著高于低Gensini积分组(OR=1.303,95%CI:1.024～1.657,P=O.031).结论 ABCG1基因上两个单核苷酸多态位点与冠心病易感性及病情严重程度具有一定相关性.