病理性近视的基因位点筛查

目的通过基因组扫描和家系连锁分析，对已知病理性近视相关位点进行筛查。方法收集符合常染色体显性遗传的病理性近视家系，选取330对微卫星标记进行基因组扫描，在显性遗传模式、基因频率0．0133和外显率100％的条件下，进行二点连锁分析和多点连锁分析。结果连锁分析在9个家系中均未发现连锁位点。第12号染色体上LODs最大0．773459，最小-8．121303，第18号染色体上LODs最大0．559933，最小-8．936928，排除了与已知病理性近视基因位点MYP2和MYP3连锁。结论我国病理性近视基因位点与国外报道不同，存在遗传异质性。病理性沂视溃传模式可能不旱单一的单蕞冈常染仁．体显件诸俜。     

常染色体显性视网膜色素变性家系基因定位的研究

目的 对一个常染色体显性视网膜色素变性大家系进行基因定位。方法 收集视网膜色素变性家系,并对该家系成员进行详细眼部检查;抽取外周血3－5ml并提取DNA;采用多个已知遗传标记与该家系致病基因位点进行连锁分析。结果 两点连锁分析结果显示该家系致病基因位点与遗传位标D3S1292连锁,在θ＝0．1时间到最大LOD值2．73。结论 D3S1292位于3号染色体长臂2区1带（3q21),从而将该家系致病基因位点大致定位于3q21附近。同时有文献报道视紫红质基因位点也位于3q染色体上,且与D3S1292邻近,因此该家系的致病基因很可能是视紫红质基因。     

*常染色体显性先天性缝合状白内障家系致病基因的定位

目的对我国一常染色体显性先天性缝合状白内障家系进行致病基因的定位。方法采集家系成员外周静脉血提取基因组DNA。选用美国Applied Biosystems公司提供的约400个遗传标记物进行基因扫描。数据经Linkage软件包进行连锁分析,初步确定致病基因所在染色体区域。在阳性区域内选取更高密度的荧光标记物进行精细扫描,用Cyrillic软件进行单体型分析。结果两点间连锁分析在D3S1279处获得最大对数优势记分（LOD）值Zmax=2．32（θmax=0．00）。通过精细扫描和单体型分析将致病基因定位于D3S1267和D3S1614之间约38．6厘摩（cM）区域内。结论先天性缝合状白内障家系的致病基因位于3号染色体3q21．1-q26．2约38．6cM区域内。（中华腥科杂志,2006,42：908—912）     

一个先天性眼外肌纤维化中国家系的基因定位

目的对一个常染色体显性遗传的先天性眼外肌纤维化(congenial fibrosis of the extraocular muscles,CFEOM)的中国家系进行基因定位。方法收集一个CFEOM中国家系,对该家系成员进行详细眼科检查,确诊为CFEOM。采集外周血5ml并抽提DNA,采用多个已知遗传标记与该家系致病基因位点进行连锁分析。结果在标记位点D12S345、D12S331及D12S1048处,lod值均大于1,其中在标记位点D12S331处获得最大lod值,lod=2.24(θ=0)。结论研究提示遗传位点与标记位点D12S345、D12S331和D12S1048存在连锁。其基因型与位于12号染色体上12p11.2-q12的CFEOM1的基因型一致。     

常染色体显性遗传先天性核性白内障一家系致病基因的初步定位

目的 初步定位一个显性遗传性先天性核性白内障家系的致病基因.方法 在已知与先天性白内障相关的致病基因附近选择合适的微卫星标记,基因组PCR扩增后进行基因分型,由LINKAGE软件处理,对该家系进行连锁分析.结果 在22q的D22S258、D22S315、D22S1163显示最大LOD值2.11（重组率θ=0）.单倍型分析提示致病基因位于D22S1174～D22S270大约18.5 Mbp的遗传距离.结论 该家系的致病基因定位于22q11.2～22q13,该范围内的CRYBB1、CRYBB2、CRYBB3、CRYBA4为其可能致病基因.     

先天性广泛眼外肌纤维化综合征一家系的连锁分析和候选基因研究

目的探讨先天性广泛眼外肌纤维化综合征(CFEOM)一家系的临床表型特征和致病基因。方法收集CFEOM一家系,对全部患者进行临床检查和全基因组扫描及连锁分析(1inkage analysis),对连锁区域内的候选基因KIf21A进行基因序列分析。结果此家系中4例患者具有典型CFEOM临床表现。连锁分析显示微卫星标记物D12S1648、D12s345、D12S1692、D12S59、D12S1090、D12S2194、D12S1048、D12S1668在家系中与全部患者的疾病表型共分离,并在D12S1090取得最大LOD值(2．12)。KIf21A基因测序未发现突变,仅在外显子21发现一单个碱基多态性改变。结论此家系属常染色体显性遗传CFEOM1型,致病基因定位于染色体带12p11．2-q12微卫星标记物D12S1648和D12S1668之间约4cM的区域。KIF21A基因可能不是此家系的致病基因。(中华眼科杂志,2005,41：594-599)     

先天性广泛眼外肌纤维化综合征一家系临床表型及基因连锁定位分析

目的 分析一个先天性广泛眼外肌纤维化综合征(CFEOM)家系的临床表型，并通过连锁分析方法来定位该家系的致病基因。方法 对家系中的所有患者进行临床检查。根据目前已知的两种常染色体显性遗传类型的CFEOM的遗传学位点12p11．2-q12(FEOM1)和16q24(FEOM3)选取微卫星进行连锁分析研究。结果 家系中4名患者具有典型的CFEOM表现。连锁分析显示，微卫星D12S59、D12S1048、D12S1648在所有患者中与疾病呈现共分离现象，其中D12S1048最大Lod值为1．91，而在微卫星D12S61和D12S1090处出现重组，表明该家系的致病基因位于这两个微卫星之间。结论此家系属常染色体显性遗传的CFEOM 1型，其致病基因定位于12p11．2-q12的D12S61和D12S1090之间。     

我国人睑裂狭小综合征患者FOXL2基因突变检测

目的研究分析我国人睑裂狭小综合征（BPES）两家系及6例散发病例的基因突变。方法选取染色体3q区域5个微卫星位点D3S3696、D3S1549、D3S3586、D3S1764和D3S1744进行家系连锁分析,应用聚合酶链反应（PER）和DNA测序技术对提示连锁的染色体区域内候选基因FOXL2进行突变筛查。结果家系连锁分析,将致病基因定位在3q23区D3S3696至D3S1744之间9．88cM范围,其中位点D3S1549、D3S3586的LOD最大值为2．11（θ=0．00）,D3S1764为1．51（θ=0．00）;对FOXL2基因突变筛查发现,2例散发患者有909—938dup30重复突变,1例散发患者有1041-1042insC移码突变,但两个家系中无突变。结论两个家系与3q23区域的D3S1549、D3S3586和D3S1764位点存在连锁。首次在散发患者中发现两种FOXL2基因突变,其中909—938dup30突变被认为是BPES综合征FOXL2基因两大突变热点之一。尚未发现突变的家系,其致病机制可能与FOXL2基因周围的位置效应,或是与提示连锁的3q23区域内其他基因相关。（中华眼科杂志,2006,42：409-414）     

先天性核性白内障家系致病基因的定位与候选基因突变检测

目的 对中国一常染色体显性遗传性先天性核性白内障家系进行致病基因的定位与候选基因突变检测.方法 实验研究.采集家系成员的外周静脉血,提取基因组DNA.用约400个中密度微卫星标记进行基因扫描,平均遗传距离10厘摩(cM).利用LINKAGE软件包进行连锁分析.在阳性定位区域内选取更为精细的微卫星标记进行精细定位.利用CYRILLIC软件进行单体型分析,确定候选基因所在染色体区域.候选基因直接测序检测基因突变.结果两点间连锁分析在微卫星标记D2S325处获得最大对数优势计分(LOD)值Zmax=2.29(θmax=0.00).精细定位和单体型分析将致病基因定位于微卫星标记D2S117和D2S2382之间,遗传距离约19.04 cM,染色体位置为2q32.3-q35.候选基因直接测序发现CRYGC基因第3外显子第470碱基一个G→A的点突变.结论本研究将我国一个先天性核性白内障家系的致病基因定位于2号染色体2q32.3-q35约19.04cM区域内,并在CRYGC基因发现一个新的点突变与此家系共分离.(中华眼科杂志,2009,45:234-238)     

原发性开角型青光眼家系致病基因的定位研究

目的采用候选位点连锁分析的方法对常染色体显性遗传的原发性开角型青光眼（POAG）一家系的致病基因进行定位。方法对重庆一大型POAG家系进行全面遗传学调查和样本采集,以短串联重复序列（STR）为分子遗传学标记,首先采用候选位点连锁分析的方法对该家系进行MYOC、OPTN、WDR36和CYP1B1基因的筛查定位,然后在阳性位点D2S2259上下游加密STR进一步行精细定位及单体型分析。结果由D2S2369、D2S2352、D2S378和D2S337所确定的染色体区域与该家系的致病基因紧密连锁（θ=0.00时,LODs分别为：D2S2369=4.584;D2S2352=2.992;D2S378=6.238;D2S337=4.892）。该区域位于人类染色体2p15～p16.3,长约7cM/7.5Mb,其中共有12个基因在眼部表达。结论研究与2007年Suriyapperuma SP等对7个欧裔成人型POAG家系的定位区域一致,且范围更小。     

New locus for autosomal dominant high myopia maps to the long arm of chromosome 17

PURPOSE: To map the gene(s) associated with autosomal dominant (AD) high-grade myopia. METHODS: A multigeneration English/Canadian family with AD severe myopia was ascertained. Myopes were healthy, with no clinical evidence of syndromic disease, anterior segment abnormalities, or glaucoma. The family contained 22 participating members (12 affected). The average age of diagnosis of myopia was 8.9 years (range, birth to 11 years). The average refractive error for affected adults was -13.925 D (range, -5.50 to -50.00). Microsatellite markers for genotyping were used to assess linkage to several candidate loci, including three previously identified AD high-myopia loci on 18p11.31, 12q22-q23, and 7q36. Syndromic myopia linkage was excluded by using intragenic or flanking markers for Stickler syndrome types 1, 2, and 2B; Marfan syndrome; Ehlers-Danlos syndrome type 4; and juvenile glaucoma. A full genome screening was performed, with 327 microsatellite markers spaced by 5 to 10 cM. Two-point linkage was analyzed using the FASTLINK program run at 90% penetrance and a myopia gene frequency of 0.0133. RESULTS: Linkage to all candidate loci was excluded. The genome screening yielded a maximum two-point lod score of 3.17 at theta = 0 with microsatellite marker D17S1604. Fine mapping and haplotype analysis defined the critical interval of 7.71 cM at 17q21-22. CONCLUSIONS: A novel putative disease locus for AD high-grade myopia has been identified and provides additional support for genetic heterogeneity for this disorder.     

Identification of a novel locus on 2q for autosomal dominant high-grade myopia

PURPOSE: Myopia, or nearsightedness, is a visual disorder of high and growing prevalence in the United States and in other countries. Pathologic high myopia, or myopia of 相似文献   

Linkage replication of the MYP12 locus in common myopia

PURPOSE: Myopia is a common disorder with a large public health impact. Although 12 myopia loci have been reported and heterogeneity for high myopia loci have been demonstrated, replication of high-myopia loci with a common myopia phenotype has not been successful. This study reports the successful replication of MYP12 in three large, multigenerational families with autosomal dominant (AD) common myopia (spherical equivalent [SphE] 相似文献   

Familial high myopia linkage to chromosome 18p

A locus for autosomal dominant high myopia was reported on chromosome 18p. We sought to confirm this finding and narrow the reported interval by analyzing high myopia among families of Hong Kong Chinese, in whom myopia is common. In 15 families with a possibly autosomal dominant inheritance of high myopia (>or=-6 dpt) in at least 2 generations, 10 chromosome 18p markers were analyzed for linkage with high myopia. Two-point linkage analysis showed trends toward linkage of markers D18S476 and D18S62 with high myopia, with maximum logarithm of odds (LOD) scores of at least 1.1 and 1.7, respectively. Multipoint analysis of those 2 markers gave a maximum LOD score of at least 2.1. To attempt to account for likely genetic heterogeneity, 5 families showing evidence of linkage of the 2 markers with high myopia were selected for further multipoint linkage analysis, resulting in a maximum LOD score of 2.4 at D18S476. While multiple genetic and environmental factors likely contribute to myopia, these data are consistent with the possibility of a locus on chromosome 18p.     

Linkage analysis of the genetic loci for high myopia on 18p, 12q, and 17q in 51 U.K. families

PURPOSE: To determine the extent to which high myopia in a cohort of 51 U.K. families can be attributed to currently identified genetic loci. METHODS: The families comprised 245 subjects with phenotypic information and DNA available, of whom 170 were classified as affected. Subjects were genotyped for microsatellite markers spanning approximately 40cM regions on 18p (MYP2), 12q (MYP3) and 17q, together with markers flanking COL2A1, COL11A1, and FBN1. Two-point linkage analyses were performed using the same disease gene segregation model as was used in the original publications, followed by nonparametric and multipoint analyses using Genehunter (http://linkage.rockefeller.edu/soft/gh/ provided in the public domain by Rockefeller University, New York, NY), with additional maximization over the parameter alpha, the proportion of linked families. RESULTS: Evidence of linkage was found for the MYP3 locus on 12q (two-point Zmax = 2.54, P = 0.0003 and multipoint hLOD = 1.08 at alpha = 0.24, P = 0.023 for marker D12S332; nonparametric linkage [NPL] = 1.49, P = 0.07 for marker D12S1607). For the 17q locus there was weak evidence of excess allele sharing and linkage under a recessive model (NPL = 1.34, P = 0.09 for marker D17S956; two-point hLOD = 1.24 at alpha = 0.30 for marker D17S1795; multipoint hLOD = 1.24 at alpha = 0.17, P = 0.014 for marker at 77.68 cM, between markers D17S956 and D17S1853). No significant linkage was found to the MYP2 locus on 18p, or to the COL2A1, COL11A1, and FBN1 genes. CONCLUSIONS: These results suggest that the MYP3 locus on 12q could be responsible for high myopia in approximately 25% of the U.K. families showing apparent autosomal dominant transmission, but that the loci on 18p and 17q are less common causes. Thus, additional loci for high myopia are likely to be the cause of the majority of cases of high myopia in the United Kingdom.     

Genomewide scan and fine mapping of quantitative trait loci for intraocular pressure on 5q and 14q in West Africans

PURPOSE: High intraocular pressure (IOP) is a major risk factor for glaucoma, one of the leading causes of blindness worldwide. Because it has been demonstrated that African populations are at increased risk for glaucoma, the authors investigated the genetic basis of IOP in a sample of West Africans with type 2 diabetes (T2D) from Ghana and Nigeria. METHODS: Genomewide linkage analysis was conducted for loci linked to IOP (measured by applanation tonometry) in 244 affected sibling pairs with T2D using 372 autosomal short-tandem repeat markers at an average spacing of 9 cM. RESULTS: Multipoint variance components linkage analyses revealed suggestive linkage on chromosome 5 (5q22) with a logarithm of odds (LOD) score of 2.50 (nominal P = 0.0003; empiric P = 0.0004) and on chromosome 14 (14q22) with an LOD score of 2.95 (nominal P = 0.0001; empiric P = 0.0003). Fine mapping at a marker density of 2 cM in the 5q region confirmed the linkage signal, with an increase in peak LOD score to 4.91. CONCLUSIONS: The strong signal on chromosome 5 lies in the region in which a novel gene, WDR36, in the GLC1G locus was recently identified as causative for adult-onset primary open-angle glaucoma and provides additional evidence that chromosome 5 contains susceptibility loci for glaucoma in multiple human populations. The evidence provided in this study is particularly important given the evolutionary history of these West African populations and the recent ancestral relationship to African Americans-a population with one of the highest rates of diabetes and associated complications (including glaucoma) in the world.     

A new locus for autosomal dominant congenital cataracts maps to chromosome 3

PURPOSE: To map a gene for cataracts in a family with congenital nuclear and sutural cataracts and to examine candidate genes in the linked region. METHODS: A large family with autosomal dominant congenital nuclear and sutural cataracts was identified and characterized. A genome-wide screen was conducted with a set of markers spaced at 10- to 15-cM intervals, and linkage was assessed using standard LOD score analysis. RESULT: Fifteen (15) affected individuals were identified. This form of congenital cataracts maps to a 12-cM region on chromosome 3q21.2-q22.3 between markers D3S3674 and D3S3612, with a maximum multipoint LOD score of 6.94 at D3S1273. The crystallin gene, CRYGS, was excluded as a candidate gene for this locus. CONCLUSIONS: There are now more than 12 different genetic loci that cause congenital cataracts. The most recent locus to be identified is on chromosome 3q21.2-q22.3, in a family with congenital nuclear and sutural cataracts.     

Autosomal dominant congenital nystagmus is not linked to 6p12, 7p11, and 15q11 in a German family

PURPOSE: Congenital nystagmus (CN) is an eye-movement disorder that usually starts within the first months of life. Autosomal dominant, autosomal recessive, and X-chromosomal pedigree patterns are observed. Causative genes are yet unknown. Several loci were implicated to contain disease-relevant genes for autosomal dominant CN (AD CN). AD CN cosegregated with a balanced translocation of 7;15 in a family. In a large black pedigree linkage was demonstrated to 6p12. DESIGN: In this study, we describe a large German family with AD congenital nystagmus. Linkage of AD in this family was tested with previously implicated loci. METHODS: Affected family members and unaffected members underwent genetic analysis. Key family members underwent ophthalmologic testing and oculography. RESULTS: No linkage of AD CN to the implicated loci on 6p12, and 7p11, and 15q11 was found in this study. CONCLUSION: In the presented pedigree genes on 15q11, and on the assumption of full penetrance, 6p12 and 7p11 are not involved in the development of AD congenital nystagmus.     

Genome-wide scan for myopia in the Old Order Amish

PURPOSE: To identify myopia susceptibility genes influencing common myopia in 34 Old Order Amish families, a genetically well-defined founder population. DESIGN: A prospective study of families with myopia consisting of a minimum of two individuals affected with myopia. METHODS: Extended families consisting of at least two siblings affected with myopia were ascertained. A genome-wide linkage scan using 387 markers was conducted by the Center for Inherited Disease Research (CIDR). Linkage analyses were conducted with parametric (autosomal dominant, fixed penetrance model) and nonparametric methods. Model-free linkage analysis was also performed maximizing over penetrance and over dominance (that is, fitting a wide range of both dominant and recessive models). RESULTS: Under the fixed penetrance model, the maximum two-point heterogeneity LOD score (HLOD) was 1.59 at D20S451 and the maximum multipoint HLOD was 1.92 at D6S1021. The nonparametric maximum multipoint (NPL) at D3S2427 had a P-value of .0005. Under the model-free analysis, multipoint heterogeneity LOD scores of 2.03 were observed on both chromosomes 8 (under a recessive model between D8S1130 and D8S1106) and X (under a recessive model between DXS6800 and DXS6789). Reanalyses of chromosomes 3, 6, 8, 20, and X using the best penetrance models resulted in maximum multipoint HLODs of 1.84 at D3S3053; 1.84 at D3S2427; 2.04 at D8S1130; and 2.34 at DXS6800. CONCLUSIONS: The locus on chromosome 8p23 independently confirms a report by Hammond and associates mapping a myopia quantitative trait loci (QTL) to this region.