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AlSaadi MM, Gaunt TR, Boustred CR, Guthrie PAI, Liu X, Lenzi L, Rainbow L, Hall N, Alharbi KK, Day INM. From a single whole exome read to notions of clinical screening: primary ciliary dyskinesia and RSPH9 p.Lys268del in the Arabian Peninsula. Ann Hum Genet 2012; 76:211-20. [PMID: 22384920 PMCID: PMC3575730 DOI: 10.1111/j.1469-1809.2012.00704.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Primary ciliary dyskinesia (PCD) is a genetic disorder, usually autosomal recessive, causing early respiratory disease and later subfertility. Whole exome sequencing may enable efficient analysis for locus heterogeneous disorders such as PCD. We whole-exome-sequenced one consanguineous Saudi Arabian with clinically diagnosed PCD and normal laterality, to attempt ab initio molecular diagnosis. We reviewed 13 known PCD genes and potentially autozygous regions (extended homozygosity) for homozygous exon deletions, non-dbSNP codon, splice-site base variants or small indels. Homozygous non-dbSNP changes were also reviewed exome-wide. One single molecular read representing RSPH9 p.Lys268del was observed, with no wild-type reads, and a notable deficiency of mapped reads at this location. Among all observations, RSPH9 was the strongest candidate for causality. Searching unmapped reads revealed seven more mutant reads. Direct assay for p.Lys268del (MboII digest) confirmed homozygosity in the affected individual, then confirmed homozygosity in three siblings with bronchiectasis. Our finding in southwest Saudi Arabia indicates that p.Lys268del, previously observed in two Bedouin families (Israel, UAE), is geographically widespread in the Arabian Peninsula. Analogous with cystic fibrosis CFTR p.Phe508del, screening for RSPH9 p.Lys268del (which lacks sentinel dextrocardia) in those at risk would help in early diagnosis, tailored clinical management, genetic counselling and primary prevention.
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Affiliation(s)
- Muslim M AlSaadi
- College of Medicine, King Saud University, P O Box 2925 Riyadh 11472, Kingdom of Saudi Arabia
| | - Tom R Gaunt
- Bristol Genetic Epidemiology Laboratories and MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, United Kingdom
| | - Christopher R Boustred
- Bristol Genetic Epidemiology Laboratories and MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, United Kingdom
| | - Philip AI Guthrie
- Bristol Genetic Epidemiology Laboratories and MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, United Kingdom
| | - Xuan Liu
- Institute of Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Luca Lenzi
- Institute of Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Lucille Rainbow
- Institute of Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Neil Hall
- Institute of Integrative Biology, Biosciences Building, Crown Street, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Khalid K Alharbi
- Clinical Laboratory Sciences Department, College of Applied Medical Sciences, King Saud University, P.O.Box 10219, Riyadh 11433, Kingdom of Saudi Arabia
| | - Ian NM Day
- Bristol Genetic Epidemiology Laboratories and MRC Centre for Causal Analyses in Translational Epidemiology, School of Social and Community Medicine, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, United Kingdom
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Talmud PJ, Cooper JA, Gaunt T, Holmes MV, Shah S, Palmen J, Drenos F, Shah T, Kumari M, Kivimaki M, Whittaker J, Lawlor DA, Day IN, Hingorani AD, Casas JP, Humphries SE. Variants of ADRA2A are associated with fasting glucose, blood pressure, body mass index and type 2 diabetes risk: meta-analysis of four prospective studies. Diabetologia 2011; 54:1710-9. [PMID: 21455730 PMCID: PMC3110279 DOI: 10.1007/s00125-011-2108-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 02/08/2011] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS We quantified the effect of ADRA2A (encoding α-2 adrenergic receptor) variants on metabolic traits and type 2 diabetes risk, as reported in four studies. METHODS Genotype data for ADRA2A single nucleotide polymorphisms (SNPs) rs553668 and rs10885122 were analysed in >17,000 individuals (1,307 type 2 diabetes cases) with regard to metabolic traits and type 2 diabetes risk. Two studies (n = 9,437), genotyped using the Human Cardiovascular Disease BeadChip, provided 12 additional ADRA2A SNPs. RESULTS Rs553668 was associated with per allele effects on fasting glucose (0.03 mmol/l, p = 0.016) and type 2 diabetes risk (OR 1.17, 95% CI 1.04-1.31; p = 0.01). No significant association was observed with rs10885122. Of the 12 SNPs, several showed associations with metabolic traits. Overall, after variable selection, rs553668 was associated with type 2 diabetes risk (OR 1.38, 95% CI 1.09-1.73; p = 0.007). rs553668 (per allele difference 0.036 mmol/l, 95% CI 0.008-0.065) and rs17186196 (per allele difference 0.066 mmol/l, 95% CI 0.017-0.115) were independently associated with fasting glucose, and rs17186196 with fasting insulin and HOMA of insulin resistance (4.3%, 95% CI 0.6-8.1 and 4.9%, 95% CI 1.0-9.0, respectively, per allele). Per-allele effects of rs491589 on systolic and diastolic blood pressure were 1.19 mmHg (95% CI 0.43-1.95) and 0.61 mmHg (95% CI 0.11-1.10), respectively, and those of rs36022820 on BMI 0.58 kg/m(2) (95% CI 0.15-1.02). CONCLUSIONS/INTERPRETATION Multiple ADRA2A SNPs are associated with metabolic traits, blood pressure and type 2 diabetes risk. The α-2 adrenergic receptor should be revisited as a therapeutic target for reduction of the adverse consequences of metabolic trait disorders and type 2 diabetes.
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Affiliation(s)
- P J Talmud
- Centre for Cardiovascular Genetics, Department of Medicine, University College London, 5 University St, London, WC1E 6JF, UK.
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Timpson NJ, Heron J, Day INM, Ring SM, Bartoshuk LM, Horwood J, Emmett P, Davey-Smith G. Refining associations between TAS2R38 diplotypes and the 6-n-propylthiouracil (PROP) taste test: findings from the Avon Longitudinal Study of Parents and Children. BMC Genet 2007; 8:51. [PMID: 17662150 PMCID: PMC1964760 DOI: 10.1186/1471-2156-8-51] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Accepted: 07/28/2007] [Indexed: 11/17/2022] Open
Abstract
Background Previous investigations have highlighted the importance of genetic variation in the determination of bitter tasting ability, however have left unaddressed questions as to within group variation in tasting ability or the possibility of genetic prescription of intermediate tasting ability. Our aim was to examine the relationships between bitter tasting ability and variation at the TAS2R38 locus and to assess the role of psychosocial factors in explaining residual, within group, variation in tasting ability. Results In a large sample of children from the Avon Longitudinal Study of Parents and Children, we confirmed an association between bitter compound tasting ability and TAS2R38 variation and found evidence of a genetic association with intermediate tasting ability. Antisocial behaviour, social class and depression showed no consistent relationship with the distribution of taste test scores. Conclusion Factors which could influence a child's chosen taste score, extra to taste receptor variation, appeared not to show relationships with test score. Observed spread in the distribution of the taste test scores within hypothesised taster groups, is likely to be, or at least in part, due to physiological differentiation regulated by other genetic contributors. Results confirm relationships between genetic variation and bitter compound tasting ability in a large sample, and suggest that TAS2R38 variation may also be associated with intermediate tasting ability.
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Affiliation(s)
- Nicholas J Timpson
- Department of Social Medicine, Bristol University, Bristol, UK
- The Wellcome Trust Centre for Human Genetics, Oxford University, Oxford, UK
| | - Jon Heron
- ALSPAC, Department of Social Medicine, Bristol University, Bristol, UK
| | - Ian NM Day
- Department of Social Medicine, Bristol University, Bristol, UK
| | - Susan M Ring
- Department of Social Medicine, Bristol University, Bristol, UK
| | - Linda M Bartoshuk
- University of Florida, Dept. of Community Dentistry and Behavioral Science, Gainesvile, USA
| | - Jeremy Horwood
- Department of Social Medicine, Bristol University, Bristol, UK
| | - Pauline Emmett
- ALSPAC, Department of Social Medicine, Bristol University, Bristol, UK
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Gaunt TR, Rodriguez S, Zapata C, Day INM. MIDAS: software for analysis and visualisation of interallelic disequilibrium between multiallelic markers. BMC Bioinformatics 2006; 7:227. [PMID: 16643648 PMCID: PMC1479374 DOI: 10.1186/1471-2105-7-227] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 04/27/2006] [Indexed: 11/10/2022] Open
Abstract
Background Various software tools are available for the display of pairwise linkage disequilibrium across multiple single nucleotide polymorphisms. The HapMap project also presents these graphics within their website. However, these approaches are limited in their use of data from multiallelic markers and provide limited information in a graphical form. Results We have developed a software package (MIDAS – Multiallelic Interallelic Disequilibrium Analysis Software) for the estimation and graphical display of interallelic linkage disequilibrium. Linkage disequilibrium is analysed for each allelic combination (of one allele from each of two loci), between all pairwise combinations of any type of multiallelic loci in a contig (or any set) of many loci (including single nucleotide polymorphisms, microsatellites, minisatellites and haplotypes). Data are presented graphically in a novel and informative way, and can also be exported in tabular form for other analyses. This approach facilitates visualisation of patterns of linkage disequilibrium across genomic regions, analysis of the relationships between different alleles of multiallelic markers and inferences about patterns of evolution and selection. Conclusion MIDAS is a linkage disequilibrium analysis program with a comprehensive graphical user interface providing novel views of patterns of linkage disequilibrium between all types of multiallelic and biallelic markers. Availability Available from and
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Affiliation(s)
- Tom R Gaunt
- Human Genetics Division, University of Southampton, School of Medicine, Duthie Building (MP 808), Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
| | - Santiago Rodriguez
- Human Genetics Division, University of Southampton, School of Medicine, Duthie Building (MP 808), Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
| | - Carlos Zapata
- Departamento de Genética, Universidad de Santiago, Santiago de Compostela, Spain
| | - Ian NM Day
- Human Genetics Division, University of Southampton, School of Medicine, Duthie Building (MP 808), Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
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Holmes C, Ballard C, Lehmann D, David Smith A, Beaumont H, Day IN, Nadeem Khan M, Lovestone S, McCulley M, Morris CM, Munoz DG, O'Brien K, Russ C, Del Ser T, Warden D. Rate of progression of cognitive decline in Alzheimer's disease: effect of butyrylcholinesterase K gene variation. J Neurol Neurosurg Psychiatry 2005; 76:640-3. [PMID: 15834019 PMCID: PMC1739631 DOI: 10.1136/jnnp.2004.039321] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To determine whether individuals with Alzheimer's disease (AD) and the K variant allele of butyrylcholinesterase have a slower rate of cognitive decline than those without the K variant allele of butyrylcholinesterase. METHOD The cognitive status of 339 community based subjects with AD was assessed with the Mini Mental State Examination at baseline and yearly over a three year follow up period. The rates of cognitive decline of subjects with and without the K variant allele were compared. RESULT Presence of the K allele was associated with a slower average rate of cognitive decline in subjects with severe AD. CONCLUSIONS This finding is consistent with the suggestion that the K variant of butyrylcholinesterase has an important role in disease progression in AD, and this may have implications for treatment.
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Affiliation(s)
- C Holmes
- University of Southampton, Clinical Neurosciences Research Division, Memory Assessment and Research Centre, Moorgreen Hospital, Botley Road, Southampton, UK.
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Lawlor DA, Day INM, Gaunt TR, Hinks LJ, Briggs PJ, Kiessling M, Timpson N, Smith GD, Ebrahim S. The association of the PON1 Q192R polymorphism with coronary heart disease: findings from the British Women's Heart and Health cohort study and a meta-analysis. BMC Genet 2004; 5:17. [PMID: 15214960 PMCID: PMC449704 DOI: 10.1186/1471-2156-5-17] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Accepted: 06/23/2004] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND There have been inconsistent results from case-control studies assessing the association of the PON1 Q192R polymorphism with coronary heart disease (CHD). Most studies have included predominantly men and the association in women is unclear. Since lipid levels vary between the sexes the antioxidant effect of PON1 and any genes associated with it may also vary by sex. We have examined the association of the PON1 Q192R polymorphism with CHD in a large cohort of British women and combined the results from our cohort study with those from all other published studies. RESULTS The distribution of genotypes was the same among women with CHD and those without disease. The odds ratio (95% confidence interval) of having CHD comparing those with either the QR or RR genotype to those with QQ genotype (dominant model of association) was 1.03 (0.89, 1.21) and the per allele odds ratio was 0.98 (0.95, 1.01). In a meta-analysis of this and 38 other published studies (10,738 cases and 17,068 controls) the pooled odds ratio for the dominant effect was 1.14 (1.08, 1.20) and for the per allele effect was 1.10 (1.06, 1.13). There was evidence of small study bias in the meta-analyses and the dominant effect among those studies with 500 or more cases was 1.05 (0.96, 1.15). Ethnicity and reporting of whether the genotyping was done blind to the participants clinical status also contributed to heterogeneity between studies, but there was no difference in effect between studies with 50% or more women compared to those with fewer women and no difference between studies of healthy populations compared to those at high risk (with diabetes, renal disease of familial hypercholesterolaemia). CONCLUSION There is no robust evidence that the PON1 Q192R polymorphism is associated with CHD risk in Caucasian women or men.
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Affiliation(s)
- Debbie A Lawlor
- Department of Social Medicine, University of Bristol, Bristol, UK
| | - Ian NM Day
- Human Genetics Division, School of Medicine, University of Southampton School of Medicine, Southampton, UK
| | - Tom R Gaunt
- Human Genetics Division, School of Medicine, University of Southampton School of Medicine, Southampton, UK
| | - Lesley J Hinks
- Human Genetics Division, School of Medicine, University of Southampton School of Medicine, Southampton, UK
| | - Patricia J Briggs
- Human Genetics Division, School of Medicine, University of Southampton School of Medicine, Southampton, UK
| | - Matthew Kiessling
- Human Genetics Division, School of Medicine, University of Southampton School of Medicine, Southampton, UK
| | - Nick Timpson
- Department of Social Medicine, University of Bristol, Bristol, UK
| | | | - Shah Ebrahim
- Department of Social Medicine, University of Bristol, Bristol, UK
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Affiliation(s)
- I N Day
- Human Genetics Division, Duthie Building (Mp808), Southampton University Hospital, Southampton SO16 6YD.
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Zhang B, Dhillon S, Geary I, Howell WM, Iannotti F, Day IN, Ye S. Polymorphisms in matrix metalloproteinase-1, -3, -9, and -12 genes in relation to subarachnoid hemorrhage. Stroke 2001; 32:2198-202. [PMID: 11546917 DOI: 10.1161/hs0901.095382] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND PURPOSE Intracranial aneurysm, which underlies the vast majority of subarachnoid hemorrhage incidences, has a multifactorial etiology, and the importance of genetic factors is increasingly recognized. Development and rupture of intracranial aneurysms involve degradation and remodeling of the vascular wall matrix in which the matrix metalloproteinases (MMPs) play an important role. The possible impact of MMP gene polymorphisms on susceptibility to intracranial aneurysms is still controversial, with conflicting data from different reported studies. METHODS In this study we analyzed 5 different functional promoter polymorphisms in the MMP-1, MMP-3, MMP-9, and MMP-12 genes in a sample of 92 patients with aneurysmal subarachnoid hemorrhage and 158 healthy control subjects, all from southern England. RESULTS No significant difference was detected between the patient and control groups in genotype distribution of any of the polymorphisms studied. CONCLUSIONS The data do not support the hypothesis that MMP gene variations influence the development of intracranial aneurysms in the population studied.
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Affiliation(s)
- B Zhang
- Human Genetics Research Division, Clinical Neurosciences Research Division, University of Southampton, School of Medicine, UK
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Abstract
Analysis of single nucleotide polymorphisms (SNPs) has been and will be increasingly utilized in various genetic disciplines, particularly in studying genetic determinants of complex diseases. Such studies will be facilitated by rapid, simple, low cost and high throughput methodologies for SNP genotyping. One such method is reported here, named tetra-primer ARMS-PCR, which employs two primer pairs to amplify, respectively, the two different alleles of a SNP in a single PCR reaction. A computer program for designing primers was developed. Tetra-primer ARMS-PCR was combined with microplate array diagonal gel electrophoresis, gaining the advantage of high throughput for gel-based resolution of tetra-primer ARMS-PCR products. The technique was applied to analyse a number of SNPs and the results were completely consistent with those from an independent method, restriction fragment length polymorphism analysis.
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Affiliation(s)
- S Ye
- Human Genetics Research Division, University of Southampton, Duthie Building (MP808), Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
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Affiliation(s)
- I N Day
- Human Genetics Research Division, Southampton University School of Medicine, Southampton SO16 6YD, UK.
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Abstract
BACKGROUND The common isoforms of apolipoprotein E (apoE), E2, E3, and E4, are important determinants of plasma lipid concentrations, and the epsilon4 allele is associated with raised risk of coronary heart disease. We investigated whether the effect of smoking on coronary heart disease risk is affected by APOE genotype. METHODS We enrolled 3052 middle-aged men who were free of coronary heart disease for prospective cardiovascular surveillance in the second Northwick Park Heart Study (NPHSII). Smoking habit was ascertained at baseline and yearly by questionnaire. APOE genotype was identified by PCR and restriction enzyme digestion. Endpoints were fatal coronary heart disease, non-fatal myocardial infarction, and coronary artery surgery and silent myocardial infarction at follow-up. FINDINGS During 18836 person years of surveillance, 96 men had an acute myocardial infarction, 26 needed coronary artery surgery, and 14 had silent myocardial infarctions. Compared with never-smokers, risk of coronary heart disease in ex-smokers was 1.34 (95% CI 0.86-2.08) and in smokers it was 1.94 (1.25-3.01). This risk was independent of other classic risk factors. In never-smokers, risk was closely similar in men with different genotypes. Risk in men homozygous for the epsilon3 allele was 1.74 (1.10-2.77) in ex-smokers and 1.68 (1.01-2.83) in smokers, whereas in men carrying the epsilon4 allele risk was 0.84 (0.40-1.75) and 3.17 (1.82-5.50), respectively, with no significant differences in risk in the epsilon2 carriers. For the epsilon3 group, the genotype effect on risk was no longer significant after adjustment for classic risk factors (including plasma lipids). However, even after adjustment, smokers who were carriers of the epsilon4 allele, showed significantly raised risk of coronary heart disease compared with the non-smoking group (2.79, 1.59-4.91, epsilon4-smoking interaction p=0.007). INTERPRETATION Smoking increases the risk of coronary heart disease in men of all genotypes but particularly in men carrying the epsilon4 allele.
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Affiliation(s)
- S E Humphries
- Centre for Cardiovascular Genetics, Department of Medicine, Royal Free and University College London Medical School, Rayne Institute, WC1E 6JJ, London, UK.
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Abstract
Studies of the association between polymorphisms of the gene for the vitamin D receptor (VDR) and adult bone mass have been inconsistent, pointing to the possibility that gene--environment interactions may vary in different populations. We have demonstrated previously an association between weight in infancy (a marker of the intrauterine and early post-natal environment) and each of adult bone mass and VDR genotype. We therefore sought to extend these observations in an elderly UK cohort and to investigate the possibility of an interaction between these genetic and early environmental markers of later osteoporosis risk. One hundred and sixty-five men and 126 women aged 61--73 years for whom birth records were available underwent bone mass measurements at baseline and follow-up 4 years later. Whole-blood samples were obtained, DNA extracted using standard techniques and polymorphisms in the VDR and collagen type I alpha 1 (Col IA1) genes identified. In the cohort as a whole, there were no significant associations between either birthweight or VDR genotype and bone mineral density (BMD) or bone loss rate at either site. However, the relationship between lumbar spine BMD and VDR genotype varied according to birthweight. Among individuals in the lowest third of birthweight, spine BMD was higher (P = 0.01) in individuals of genotype 'BB' after adjustment for age, sex and weight at baseline. In contrast, spine BMD was reduced (P = 0.04) in individuals of the same genotype who were in the highest third of the birthweight distribution. A significant (P = 0.02) statistical interaction was also found between VDR genotype and birthweight as determinants of BMD. Similar but slightly weaker associations were seen between lumbar spine bone mineral content (BMC) and VDR genotype in the lowest birthweight tertile. When examining the relationship between Col1A1 genotype and bone mass, lumbar spine BMC was higher in individuals of genotype 'Ss' or 'ss' in the lowest birthweight tertile (P = 0.02) after adjustment for age, sex and weight at baseline. These results suggest that genetic influences on adult bone size and mineral density may be modified by undernutrition in utero.
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Affiliation(s)
- E M Dennison
- MRC Environmental Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, UK
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Gaunt TR, Cooper JA, Miller GJ, Day IN, O'Dell SD. Positive associations between single nucleotide polymorphisms in the IGF2 gene region and body mass index in adult males. Hum Mol Genet 2001; 10:1491-501. [PMID: 11448941 DOI: 10.1093/hmg/10.14.1491] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We previously demonstrated an association between the insulin-like growth factor 2 (IGF2) gene 3'-untranslated region (3'-UTR) ApaI polymorphism and body mass index (BMI) in over 2500 middle-aged Caucasoid males. In the same cohort, we have now tested association with 11 more markers, including seven novel single nucleotide polymorphisms (SNPs), spanning >30 kb across the IGF2 gene. Three SNPs showed significant positive associations with BMI: 6815 A/T in the IGF2 P1 promoter (P = 0.00012, n = 2394) and the newly identified SNPs 1156 C/T in intron 2 (P = 0.017, n = 1567) and 1926 C/G in the 3'-UTR (P = 0.0062, n = 1872). There was strong pairwise linkage disequilibrium (LD) between the ApaI and 1926 C/G sites, whereas LD between ApaI and 6815 A/T, and between ApaI and 1156 T/C, was minimal. Univariately 6815 A/T, 1156 T/C and ApaI explained 1.03, 1.02 and 0.67% of the variation in BMI. Multi-way analysis of variance (ANOVA) models showed that 6815 A/T and 1156 T/C explained a further 0.4 and 0.8% of the variation beyond that accounted for by ApaI and the association of 1926 C/G with BMI disappeared after adjustment. The 6815 A/T, 1156 T/C and ApaI markers in effect constitute independent affirmations of our original hypothesized candidate gene region. In a stepwise multi-way ANOVA model, all three terms were significantly independently associated with BMI. The total proportion of BMI variance explained by this model was 2.25%, strongly suggesting that IGF2 genetic variation is a significant determinant of body weight in middle-aged males.
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Affiliation(s)
- T R Gaunt
- Human Genetics Research Division, University of Southampton School of Medicine, Duthie Building (MP 808), Southampton General Hospital, Tremona Road, Southampton S016 6YD, UK
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Holloway JW, Ye S, Day IN. Tools for molecular genetic epidemiology: a comparison of MADGE methodology with other systems. Biotechnol Genet Eng Rev 2001; 17:71-88. [PMID: 11255682 DOI: 10.1080/02648725.2000.10647988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- J W Holloway
- Human Genetics Research Division, University of Southampton, Duthie Building (808), Southampton General Hospital, Tremona Road, Southampton S016 6YD, U.K.
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Abstract
Cigarette smoking causes vascular endothelial dysfunction and is a major risk factor for cardiovascular diseases. Nicotine, a major constituent of cigarette smoke, has been shown to alter gene expression in endothelial cells; however, the regulatory pathways involved remain to be defined. We hypothesized that there might be distinct pathways that could be identified by systematic transcriptome analysis. Using the cDNA microarray approach, we ascertained the expression of over 4,000 genes in human coronary artery endothelial cells and identified a number of nicotine-modulated genes encoding a protein involving in signal transduction or transcriptional regulation. Among these were phosphatidylinositol phosphate kinase and diacylglycerol kinase, which are regulators of the inositol phospholipid pathway. Changes were also detected for transcription factors cAMP response element binding protein and nuclear factor-kappaB, of which the activities of both have been previously shown to be altered in nicotine-stimulated cells. The data from this study are relevant to understanding the mechanisms underlying the pathophysiological effect of nicotine and smoking, particularly on endothelial function and pathogenesis of atherosclerosis.
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Affiliation(s)
- S Zhang
- Human Genetics Research Division, School of Medicine, University of Southampton, Southampton, SO16 6YD, United Kingdom
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Abstract
A new modification of the microplate array diagonal gel electrophoresis (MADGE) system accommodates the dual amplification refractory mutation system (ARMS) products of 96 samples on one 192-well gel. Simultaneous electrophoresis of a number of horizontal ARMS-MADGE gels achieves high throughput. Gels are imaged digitally, here using the FluorImager 595 fluorescent scanning system. Customized software by Phoretix enables rapid computerized calling of band patterns in ARMS-MADGE arrays, in which the two wells receiving a pair of allele-specific assays for a single template are juxtaposed to form one virtual track, with genotype data exported directly into Microsoft Excel for statistical analysis. An ARMS assay of the A/T base change at the -23/HphI RFLP in the insulin gene promoter, which initiates from 2.5 ng template DNA, was used here to demonstrate this improved general approach for population SNP analyses.
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Affiliation(s)
- S D O'Dell
- Human Genetics Research Division, Southampton University Medical School, Southampton General Hospital, England, UK. s.d.o'
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Gu DF, Hinks LJ, Morton NE, Day IN. The use of long PCR to confirm three common alleles at the CYP2A6 locus and the relationship between genotype and smoking habit. Ann Hum Genet 2000; 64:383-90. [PMID: 11281276 DOI: 10.1046/j.1469-1809.2000.6450383.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Long PCR followed by nested PCR has previously been used to determine CYP2A6 160H alleles, but the method proved unreliable. We have optimized this approach in a DNA bank of 1032 subjects (age range 59-74 years) to give reliable results, yielding indirect molecular evidence and very strong statistical evidence of hitherto unrecognized common alleles (designated O) recalcitrant to the long PCR. Coding three alleles (160L, 160H and O) and an approach to association analysis originally developed to deal with null alleles implicit in ABO blood group phenotyping, the contribution of 160H (functionally null) to reduced smoking habit has been clearly measured for the first time, unconfounded by alleles null to the long PCR. The most significant findings (p < 0.01) are that the possession of a 160H allele, compared with not possessing a 160H allele, is associated with a mean age of starting regular smoking 3 years later (95% CI +/- 1.93 years, average start age 20-21 years rather than 17-18 years); and that the average likelihood of quitting smoking at any time is 1.75 fold (95% CI, 1.17-2.61) for those possessing an 160H allele compared with those who have no 160H allele. This suggests that a smoking subject with a genotype predicted to confer 50% of the ability to eliminate nicotine via the CYP2A6 pathway has almost twice the likelihood of quitting smoking.
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Affiliation(s)
- D F Gu
- Research Division of Human Genetics, Southampton University Medical School, Southampton University Hospital, UK
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18
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Abstract
The 5' polymorphic region of the insulin (INS, MIM# 176730) gene contains a variable tandem repetition of 14-15 bp (a variable number of tandem repeats (VNTR) locus). After PCR amplification, we achieved precise sizing of class I alleles (range 641 to 843 bp) on 96-well open-face polyacrylamide microplate array diagonal gel electrophoresis (MADGE) gels, obtaining resolution of the 2% mobility difference which represents one tandem repeat. PCR products were run double-stranded, but no additional bands were generated except in the case of differences of three, two, and one repeat between alleles; none compromised allele identification, and in the latter case the heteroduplex was a useful confirmation signal. No end labelling of primers was required, as the sensitive Vistra Green intercalating dye for double strands was used for visualization of bands from diluted samples. Duracryl, a high mechanical-strength polyacrylamide derivative, proved to have good resolution properties for electrophoresis. A co-run ladder ensured precise binning without inter-lane variability. Simultaneous electrophoresis of gels in a thermostatically controlled tank allowed up to 1,000 samples to be run in 90 min. Gels were analyzed using a FluorImager 595 fluorescent scanning system, and alleles identified using a combination of Phoretix software for band migration measurement and Microsoft Excel to compute allele sizes. Unlike other systems for minisatellite allele sizing, throughput was not limited (in time or cost) by electrophoresis.
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Affiliation(s)
- S D O'Dell
- Human Genetics Research Division, Southampton University School of Medicine, Southampton General Hospital, Southampton, United Kingdom. S.D.O'
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19
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Abstract
Familial hypercholesterolemia by usual definition reflects mutations of the LDL-receptor gene. Extensive molecular characterization of mutations ascertained mainly through homozygotes (the Dallas collection) has been presented by Hobbs et al. (Hum Mutat 1:445-446, 1992). This paper catalogues a spectrum of 134 mutations (27 novel mutations in 45 patients, 24 previously described mutations in 89 patients) ascertained through heterozygotes from the analysis of 791 patients with definite, probable, or possible FH, mainly from the UK, using high-throughput modifications of the single-strand conformation polymorphism technique. From a composite database of LDL receptor gene mutations complied from these two sets and from the literature, deductions are made about ascertainment bias, mutation rates, and molecular heterogeneity. Calculations suggest that there may be a large number of rare amino acid variants in the general population not causing classic FH. Approaches to, and feasibility of, molecular diagnostics are considered.
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Affiliation(s)
- I N Day
- Department of Medicine, Rayne Institute, University College of London Medical School, UK
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20
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Mavroidis N, Traeger-Synodinos J, Kanavakis E, Drogari E, Matsaniotis N, Humphries SE, Day IN, Kattamis C. A high incidence of mutations in exon 6 of the low-density lipoprotein receptor gene in Greek familial hypercholesterolemia patients, including a novel mutation. Hum Mutat 2000; 9:274-6. [PMID: 9090532 DOI: 10.1002/(sici)1098-1004(1997)9:3<274::aid-humu10>3.0.co;2-#] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- N Mavroidis
- First Department of Pediatrics, University of Athens, St. Sophia's Children's Hospital, Greece
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21
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Heath KE, Day IN, Humphries SE. Universal primer quantitative fluorescent multiplex (UPQFM) PCR: a method to detect major and minor rearrangements of the low density lipoprotein receptor gene. J Med Genet 2000; 37:272-80. [PMID: 10745045 PMCID: PMC1734566 DOI: 10.1136/jmg.37.4.272] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A method based on quantitative fluorescent multiplex PCR has been developed to detect major rearrangements of the low density lipoprotein receptor gene (LDLR) which account for approximately 5% of mutations. The method involves two PCR reactions; the first (P1) amplifies the selected exons using unique primer sequences tagged with newly designed universal primers, while the second (P2) amplifies the P1 amplicons using the universal primers. One of the P2 universal primers is labelled with a fluorescent dye which is incorporated into the PCR products which are then electrophoresed on an ABI DNA sequencer. The relative amounts of the amplified peak areas are determined and compared to ratios obtained for DNA from four normal controls and known major rearrangements. The multiplex set developed is based on LDLR exons 3, 5, 8, 14, and 17 and 86% of reported major rearrangements would be detectable by this assay as well as any deletions and insertions of greater than 1 bp. The method was evaluated using DNA from 15 reported deletions and duplications which were all correctly identified. Two groups of UK patients with a clinical diagnosis of familial hypercholesterolaemia (FH) and where no mutation had been identified in LDLR or APOB (14 children and 42 adults) were screened for the presence of major LDLR rearrangements by this assay. Three major rearrangements were detected and a 4 bp duplication was identified in a fourth patient. Since it avoids the problems associated with Southern blotting, this method will be useful for detecting gene rearrangements.
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Affiliation(s)
- K E Heath
- Centre for Cardiovascular Genetics, The Rayne Institute, University College Medical School, 5 University Street, London WC1E 6JJ, UK
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22
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Affiliation(s)
- A M Voropanov
- Division of Human Genetics, School of Medicine, Southampton University, Southampton General Hospital, England, UK.
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23
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Abstract
Body mass index (BMI) is an established epidemiological predictor of coronary disease, diabetes and hypertension. In a previous study of 2560 healthy British Caucasoid males aged 50-61 years (Northwick Park Heart Study II; NPHSII), we showed that IGF2 ApaI AA homozygotes display a mean body weight 3.3 kg lower than GG homozygotes (P = 0.0002) independent of height. Two RFLPs in the insulin (INS) gene, +1127/PstI shown previously and -23/HphI in this study, both of which are in strong linkage disequilibrium with class I/III alleles of the INS 5' variable number tandem repeat (VNTR), are not associated with weight or BMI. The IGF2 ApaI polymorphism therefore appears to mark an effect independent of INS VNTR class I vs class III. We now show by regression that there is a positive correlation of BMI with INS VNTR class I allele size, with an average 0.33% (95% CI = 0.13%, 0.50%) increase in BMI per extra tandem repeat (P < 0.0001) representing variation of 4.8% over the allele size range. However, an alternative interpretation is of 'step' rather than 'slope', the small class I subclass allele group (mode 669 bp) being lighter than the large subclass group (mode 814 bp). This small effect would not be evident as an association between INS VNTR class I/I1 genotype and BMI. The IGF2 ApaI association and INS VNTR class I subclass regression association account for at least 1.1% of population BMI variance. Neither, both, or a third site may be aetiological.
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Affiliation(s)
- S D O'Dell
- Human Genetics Research Division, Southampton University School of Medicine, UK. S.D.O'
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24
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Holloway JW, Beghé B, Turner S, Hinks LJ, Day IN, Howell WM. Comparison of three methods for single nucleotide polymorphism typing for DNA bank studies: sequence-specific oligonucleotide probe hybridisation, TaqMan liquid phase hybridisation, and microplate array diagonal gel electrophoresis (MADGE). Hum Mutat 1999; 14:340-7. [PMID: 10502782 DOI: 10.1002/(sici)1098-1004(199910)14:4<340::aid-humu10>3.0.co;2-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the near future the number of SNPs identified and mapped will increase and the need for high throughput SNP typing will be paramount for comprehensive examination by association of the role of genomic regions in disease traits. A range of higher throughput methods for typing SNPs is now in routine use in many laboratories worldwide. In this report, we analyse the relative advantages and disadvantages of three such methods, TaqMan, PCR-SSOP, and ARMS-MADGE, currently in use in our laboratories. Throughputs achievable are similar, but there are major differences in cost and time for set-up, equipment, consumables, and staff time, which may determine the choice for individual laboratories.
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Affiliation(s)
- J W Holloway
- Human Genetics Research Division, University of Southampton, Southampton General Hospital, Southampton, UK.
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25
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Humphries SE, Luong LA, Montgomery HE, Day IN, Mohamed-Ali V, Yudkin JS. Gene-environment interaction in the determination of levels of plasma fibrinogen. Thromb Haemost 1999; 82:818-25. [PMID: 10605788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- S E Humphries
- Department of Medicine, Royal Free & University College London Medical School, Rayne Institute, United Kingdom
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26
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Abstract
Molecular genetic epidemiology, association and linkage studies in populations, human or other species, is now yielding powerful new insights into disease and susceptibility genes. Inter alia, the subject requires laboratory analytical methodologies focused on achieving high throughput. Here we review one suite of methodology suitable for such laboratories. Microplate array diagonal gel electrophoresis (MADGE) was invented for molecular genetic epidemiological studies. It combines direct compatibility with microplates, convenient polyacrylamide gel electrophoresis and economy of time and reagents, at minimal capital cost, and enables one user to run up to several thousand gel lanes per day for direct assay of single-base variations. Melt-MADGE combines temporal thermal ramp apparatus to achieve similar throughput for de novo mutation scanning.
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Affiliation(s)
- I N Day
- Wessex Human Genetics Institute, Southampton University Hospitals NHS Trust, UK.
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27
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Haddad L, Day IN, Hunt S, Williams RR, Humphries SE, Hopkins PN. Evidence for a third genetic locus causing familial hypercholesterolemia. A non-LDLR, non-APOB kindred. J Lipid Res 1999; 40:1113-22. [PMID: 10357843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Monogenically inherited hypercholesterolemia is most commonly caused by mutations at the low density lipoprotein receptor (LDLR) locus causing familial hypercholesterolemia (FH) or at the apolipoprotein B (APOB) locus causing the disorder familial defective apoB (FDB). Probands from 47 kindreds with a strict clinical diagnosis of FH were selected from the Cardiovascular Genetics Research Lipid Clinic, Utah, for molecular genetic analysis. Using a combination of single-strand conformation polymorphism (SSCP) and direct sequencing, 12 different LDLR gene mutations were found in 16 of the probands. Three of the probands were carriers of the APOB R3500Q mutation. In five of the remaining 28 pedigrees where no mutation had been detected, samples from enough relatives were available to examine co-segregation with the LDLR region using the microsatellite marker D19S221, which is within 1 Mb centromeric of the LDLR locus, and D19S394, sited within 150 kb telomeric of the LDLR locus. In four of the families there was strong evidence for co-segregation between the LDLR locus and the phenotype of hypercholesterolemia, but in one large family with 18 living affected members and clear-cut bimodal hypercholesterolemia, there were numerous exclusions of co-segregation. Using length polymorphic markers within and outside the APOB gene, linkage of phenotype in this family to the APOB region was similarly excluded. In this large family, the degree of hypercholesterolemia, prevalence of tendon xanthomata, and occurrence of early coronary disease were indistinguishable from the other families studied. In summary, the data provide unequivocal evidence that a third locus can be etiological for monogenic familial hypercholesterolemia and should be reinvigorating to research in this field.
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Affiliation(s)
- L Haddad
- Centre for Cardiovascular Genetics, Department of Medicine, University College London Medical School, The Rayne Institute, 5 University Street, London WC1E 6JJ, United Kingdom
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28
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Day IN, O'Dell SD, Spanakis E, Weavind GP. Microplate array diagonal gel electrophoresis (MADGE), CpG-PCR and temporal thermal ramp-MADGE (Melt-MADGE) for single nucleotide analyses in populations. Genet Anal 1999; 14:197-204. [PMID: 10084115 DOI: 10.1016/s1050-3862(98)00027-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Important requirements for molecular genetic epidemiological studies are economy, sample parallelism, convenience of setup and accessibility, goals inadequately met by existent approaches. We invented microplate array diagonal gel electrophoresis (MADGE) to gain simultaneously the advantages of simple setup, 96-well microplate compatibility, horizontal electrophoresis, and the resolution of polyacrylamide. At essentially no equipment cost (one simple plastic gel former), 10-100-fold savings on time for sample coding, liquid transfers, and data documentation, in addition to volume reductions and gel re-use, can be achieved. MADGE is compatible with ARMS, restriction analysis and other pattern analyses. CpG-PCR is a general PCR approach to CpG sites (10-20% of all human single base variation): both primers have 3' T, and are abutted to the CpG, forcing a TaqI restriction site if the CpG is intact. Typically, a 52 bp PCR product is then cut in half. CpG-PCR also illustrates that PAGE-MADGE readily permits analysis of 'ultrashort' PCRs. Melt-MADGE employs real-time-variable-temperature electrophoresis to examine duplex mobility during melting, achieving DGGE-like de novo, mutation scanning, but with the conveniences of arbitrary programmability, MADGE compatibility and short run time. This suite of methods enhances our capability to type or scan thousands of samples simultaneously, by 10-100-fold.
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Affiliation(s)
- I N Day
- Wessex Human Genetics Institute, Southampton University Hospitals NHS Trust, UK.
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29
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Lee WK, Haddad L, Macleod MJ, Dorrance AM, Wilson DJ, Gaffney D, Dominiczak MH, Packard CJ, Day IN, Humphries SE, Dominiczak AF. Identification of a common low density lipoprotein receptor mutation (C163Y) in the west of Scotland. J Med Genet 1998; 35:573-8. [PMID: 9678702 PMCID: PMC1051368 DOI: 10.1136/jmg.35.7.573] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Familial hypercholesterolaemia (FH) is an autosomal codominant disorder characterised by high levels of LDL cholesterol and a high incidence of coronary artery disease. Our aims were to track the low density lipoprotein receptor (LDLR) gene in individual families with phenotypic FH and to identify and characterise any mutations of the LDLR gene that may be common in the west of Scotland FH population using single strand conformational polymorphism analysis (SSCP). Patient samples consisted of 80 heterozygous probands with FH, 200 subjects who were related to the probands, and a further 50 normal, unrelated control subjects. Tracking of the LDLR gene was accomplished by amplification of a 19 allele tetranucleotide microsatellite that is tightly linked to the LDLR gene locus. Primers specific for exon 4 of the LDLR gene were used to amplify genomic DNA and used for SSCP analysis. Any PCR products with different migration patterns as assessed by SSCP were then sequenced directly. In addition to identifying probands with a common mutation, family members were screened using a forced restriction site assay and analysed using microplate array diagonal gel electrophoresis (MADGE). Microsatellite D19S394 analysis was informative in 20 of 23 families studied. In these families there was no inconsistency with segregation of the FH phenotype with the LDLR locus. Of the FH probands, 15/80 had a mutant allele as assessed by SSCP using three pairs of primers covering the whole of exon 4 of the LDLR gene. Direct DNA sequencing showed that 7/15 of the probands had a C163Y mutation. Using a PCR induced restriction site assay for the enzyme RsaI and MADGE, it was determined that the C163Y mutation cosegregated with the FH phenotype in family members of the FH probands. This mutant allele was not present in any of the control subjects. Microsatellite analysis has proven useful in tracking the LDLR gene and could be used in conjunction with LDL cholesterol levels to diagnose FH, especially in children and young adults where phenotypic diagnosis can be difficult.
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Affiliation(s)
- W K Lee
- Department of Medicine and Therapeutics, Gardiner Institute, Western Infirmary, Glasgow, UK
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30
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Day IN, Spanakis E, Palamand D, Weavind GP, O'Dell SD. Microplate-array diagonal-gel electrophoresis (MADGE) and melt-MADGE: tools for molecular-genetic epidemiology. Trends Biotechnol 1998; 16:287-90. [PMID: 9675913 DOI: 10.1016/s0167-7799(98)01217-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Microplate-array diagonal-gel electrophoresis (MADGE) was invented for molecular-genetic epidemiological studies. It combines direct compatibility with microplates, convenient polyacrylamide-gel electrophoresis and economy of time and reagents at minimal capital cost, and enables one user to run up to several-thousand gel lanes per day for the direct assay of single-base variations. Melt-MADGE adds temporal-thermal-ramp apparatus to achieve similar throughput for de novo mutation scanning.
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Affiliation(s)
- I N Day
- Wessex Human Genetics Institute, University of Southampton, UK.
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31
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Abstract
Insulin-like growth factor II (IGF-II) plays a key role in mammalian growth, influencing foetal cell division and differentiation and possibly metabolic regulation. The mature 67 amino acid peptide shares sequence homology with both insulin and IGF-I. The liver is the main endocrine source of IGFs, but autocrine/paracrine activity is found in most tissues. The type 1 receptor mediates most of the biological effects of IGF-I and IGF-II; the type 2 receptor is involved with IGF-II degradation. Binding proteins may both localise IGFs to the receptors and regulate their activities. The IGF2 gene is maternally imprinted in mouse and human. Relaxation of IGF2 imprinting occurs in the Beckwith-Wiedemann syndrome of somatic overgrowth, sporadic Wilms' tumour and a number of other cancers. In the general adult population, the IGF2-INS gene cluster may also influence body weight, in which case IGF-II function could become a target for therapeutic intervention in obesity.
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Affiliation(s)
- S D O'Dell
- Wessex Human Genetics Institute, Southampton University Hospitals NHS Trust, UK. s.d.o'
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32
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Wilson DJ, Gahan M, Haddad L, Heath K, Whittall RA, Williams RR, Humphries SE, Day IN. A World Wide Web site for low-density lipoprotein receptor gene mutations in familial hypercholesterolemia: sequence-based, tabular, and direct submission data handling. Am J Cardiol 1998; 81:1509-11. [PMID: 9645910 DOI: 10.1016/s0002-9149(98)00215-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Familial hypercholesterolemia is an autosomal dominant inherited condition characterized by a mutation in the low-density lipoprotein receptor (LDLR) gene. A database has been set up on the World Wide Web for mutations in the LDLR gene.
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Affiliation(s)
- D J Wilson
- Department of Medicine, University College London Medical School, Rayne Institute, United Kingdom
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33
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De Oliveira e Silva ER, Haddad L, Kwiterovich PO, Humphries SE, Day IN. Applicability of LDLR flanking microsatellite polymorphisms for prenatal diagnosis of homozygous state for familial hypercholesterolemia. Clin Genet 1998; 53:375-8. [PMID: 9660055 DOI: 10.1111/j.1399-0004.1998.tb02748.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Analysis of newly identified microsatellite polymorphisms flanking the low density lipoprotein receptor (LDLR) gene was undertaken in the kindred of a child with apparent homozygous LDLR deficiency. The applicability of these approaches to prenatal diagnosis is considered and compared with previous approaches applying functional studies of the LDLR in amniotic fibroblasts.
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Affiliation(s)
- E R De Oliveira e Silva
- Laboratory of Biochemical Genetics and Metabolism, The Rockefeller University, New York, NY 10021-6399, USA
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34
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Abstract
We have investigated the W64R (Trp64Arg) mutation in the beta-3-adrenergic receptor in 2270 healthy British males aged 50-61 y. The frequency of the rare R allele was 0.07 (95% confidence interval (CI) 0.06-0.08). The men showed an absence of association between W64R genotype and weight or height, both in the whole sample and in each quintile of the body mass index (BMI), and there was no association with tendency to gain weight. The W64R heterozygous state appears not to be a major contributing factor to obesity in the general population.
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Affiliation(s)
- S D O'Dell
- Department of Medicine, University College London Medical School, The Rayne Institute, UK. S.D.O'
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35
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Traeger-Synodinos J, Mavroidis N, Kanavakis E, Drogari E, Humphries SE, Day IN, Kattamis C, Matsaniotis N. Analysis of low density lipoprotein receptor gene mutations and microsatellite haplotypes in Greek FH heterozygous children: six independent ancestors account for 60% of probands. Hum Genet 1998; 102:343-7. [PMID: 9544850 DOI: 10.1007/s004390050703] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study reports the characterization of 60% of low density lipoprotein receptor (LDLR) gene mutations in 150 unrelated Greek familial hypercholesterolaemia (FH) heterozygous children by the analysis of six LDLR gene mutations. The linkage disequilibrium of two polymorphic microsatellites (D19S394 and D19S221) flanking the LDLR gene on chromosome 19 to the four most common mutations strongly suggests that each mutation is identical-by-descent in the probands included in this study (this is also supported by the geographical distribution of FH families with these mutations throughout Greece) and permits an estimation of the number of generations from a common ancestor for each mutation. The characterization of 60% of LDLR mutations in a representative sample of Greek FH heterozygotes provides a basis for the diagnosis of FH through DNA analysis in Greece, by using single-strand conformation polymorphism analysis followed by allele-specific oligonucleotide hybridization (exon 6 mutations) or restriction endonuclease analysis (C152R, V408M). A rapid diagnostic assay positive for the mutation has been developed for the most common mutation, G528D. The application of simple DNA diagnostic assays for LDLR mutation analysis are appropriate for the early identification of FH heterozygotes in Greece and are useful for the primary prevention of coronary artery disease.
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Affiliation(s)
- J Traeger-Synodinos
- First Department of Pediatrics, University of Athens, St. Sophia's Children's Hospital, Greece
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36
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Wenham PR, Haddad L, Panarelli M, Ashby JP, Day IN, Giles PD, Humphries SE, Penney MD, Rae PW, Walker SW. Simplified detection of a mutation causing familial hypercholesterolaemia throughout Britain: evidence for an origin in a common distant ancestor. Ann Clin Biochem 1998; 35 ( Pt 2):226-35. [PMID: 9547893 DOI: 10.1177/000456329803500205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Familial hypercholesterolaemia (FH) is an inherited autosomal codominant disorder caused by many different mutations in the low-density lipoprotein receptor (LDLR) gene. The one described most frequently in patients with FH from England, arises from a G-->A transition at the first nucleotide of codon 80, resulting in the substitution of lysine for glutamic acid at residue 80 of the mature protein, FH E80K. We describe a simple method to detect this mutation in genomic DNA using the polymerase chain reaction (PCR). A 69 base pair (bp) fragment of exon 3 of the LDLR gene is amplified using a mutagenic upstream PCR primer. This substitutes a T for an A residue in the amplified product, 2 bp upstream from the mutant site, generating a restriction site for the endonuclease Taq I, in normal, but not in mutant DNA. Following digestion of amplified DNA with Taq I, normal but not mutant DNA is cut into two fragments of 29 and 40 bp, which are readily identified by polyacrylamide gel electrophoresis. Using this method, 410 patients with clinically diagnosed FH, attending lipid clinics in Edinburgh (72), Newport (158), Walsall (30) and Southampton (150), were screened for the mutation. Five individuals tested positive as heterozygotes, one from Edinburgh, three from Newport and one from Southampton. This finding was confirmed by DNA sequence analysis. We conclude that FH due to this mutation occurs in individuals throughout Great Britain and that it can be detected accurately using this simple technique. DNA from these and other individuals previously identified to be heterozygous for FH E80K, was then studied using PCR of highly informative microsatellite markers flanking the LDLR gene. Sixteen of 17 apparently unrelated individuals heterozygous for FH E80K also were heterozygous for an identical size (239 nucleotide) allele, of polymorphic microsatellite D19S394, located approximately 250 kb away from the LDLR gene. This supports the hypothesis that FH E80K in these 16 individuals arose from a single ancestor less than 1000 years ago.
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Affiliation(s)
- P R Wenham
- Department of Clinical Biochemistry, Western General Hospital, Edinburgh, UK
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37
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Austin MA, Talmud PJ, Luong LA, Haddad L, Day IN, Newman B, Edwards KL, Krauss RM, Humphries SE. Candidate-gene studies of the atherogenic lipoprotein phenotype: a sib-pair linkage analysis of DZ women twins. Am J Hum Genet 1998; 62:406-19. [PMID: 9463319 PMCID: PMC1376888 DOI: 10.1086/301712] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
There is a growing body of evidence supporting the roles of small, dense LDL and plasma triglyceride (TG), both features of the atherogenic lipoprotein phenotype, as risk factors for coronary heart disease. Although family studies and twin studies have demonstrated genetic influences on these risk factors, the specific genes involved remain to be determined definitively. The purpose of this study was to investigate genetic linkage between LDL size, TG, and related atherogenic lipoproteins and candidate genes known to be involved in lipid metabolism. The linkage analysis was based on a sample of 126 DZ women twin pairs, which avoids the potentially confounding effects of both age and gender, by use of a quantitative sib-pair linkage-analysis approach. Eight candidate genes were examined, including those for microsomal TG-transfer protein (MTP), hepatic lipase, hormone-sensitive lipase, apolipoprotein (apo) B, apo CIII, apo E, insulin receptor, and LDL receptor. The analysis suggested genetic linkage between markers for the apo B gene and LDL size, plasma levels of TG, of HDL cholesterol, and of apo B, all features of the atherogenic lipoprotein phenotype. Furthermore, evidence for linkage was maintained when the analysis was limited to women with a major LDL-subclass diameter >255 A, indicating that the apo B gene may influence LDL heterogeneity in the intermediate-to-large size range. In addition, linkage was found between the MTP gene and TG, among all the women. These findings add to the growing evidence for genetic influences on the atherogenic lipoprotein phenotype and its role in genetic susceptibility to atherosclerosis.
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Affiliation(s)
- M A Austin
- Department of Epidemiology, School of Public Health and Community Medicine, University of Washington, Seattle, WA 98195, USA.
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38
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Bolla MK, Miller GJ, Yellon DM, Evans A, Luc G, Cambou JP, Arveiler D, Cambien F, Latchman DS, Humphries SE, Day IN. Analysis of the association of a heat shock protein70-1 gene promoter polymorphism with myocardial infarction and coronary risk traits. Dis Markers 1998; 13:227-35. [PMID: 9553737 DOI: 10.1155/1998/235151] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Heat shock proteins (HSP) are induced during coronary ischaemia, and abnormal expression of one HSP gene may cause hypertension in rats. We examined association of a promoter polymorphism in the major stress-inducible hsp70 gene (hsp70-1 or HSP70A1) on chromosome 6 (p21.3) with coronary disease traits. This C-->A base substitution (AAACCCC) is at nucleotide position-110 in the heat shock transcription factor binding site (heat shock element, HSE). The first study sample (ECTIM), recruited from Belfast and three centers in France, consisted of 578 myocardial infarction cases and 698 age-matched controls. The frequency of the A-110 allele was 0.381 (95% CI = 0.35-0.41) and 0.384 (95% CI = 0.36-0.41) in cases and controls respectively. Homozygotes for the rarer A-110 allele had a higher BMI (27.3 kg/m2 +/- 3.9) compared with homozygotes for the common C-110 allele (26.3 kg/m2 +/- 3.3). The rarer homozygotes were shorter and heavier than the common homozygotes. A follow-up study involved 1431 healthy, middle aged men from the UK (NPHS II group). The frequency of the A-110 allele was 0.385 (95% CI = 0.37-0.40), and there was no association of genotype with BMI. Thus there appears to be no strong association of the Hsp70-1 promoter polymorphism with risk of myocardial infarction, BMI or any coronary disease traits analysed here.
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Affiliation(s)
- M K Bolla
- Department of Medicine, University College London Medical School, Rayne Institute, UK.
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39
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O'Dell SD, Wilson DJ, Durrington PN, Humphries SE, Day IN. CpG-PCR combined with sample pooling and mutant enrichment for CpG mutation screening in population studies. Clin Chem 1998; 44:183-5. [PMID: 9550579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S D O'Dell
- Dept. of Med., Univ. College London Med. School, The Rayne Inst., UK.
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40
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Nissen H, Day LB, Horder M, Humphries SE, Day IN. Denaturing gradient gel electrophoretic analysis of codons 3456-3553 of the apolipoprotein-B gene in 106 type 11a hyperlipoproteinaemic individuals. Ann Clin Biochem 1998; 35 ( Pt 1):137-9. [PMID: 9463753 DOI: 10.1177/000456329803500120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- H Nissen
- Department of Clinical Chemistry, Odense University Hospital, Denmark
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41
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Humphries SE, Gudnason V, Whittall R, Day IN. Single-strand conformation polymorphism analysis with high throughput modifications, and its use in mutation detection in familial hypercholesterolemia. The IFCC Scientific Division: Committee on Molecular Biology Techniques. J Int Fed Clin Chem 1997; 9:156-61. [PMID: 10177224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The identification of the specific mutation causing an inherited disease in a patient is the framework for the development of a rationale for therapy and of DNA-based tests for screening relatives. We present here a review of the single-strand conformational polymorphism (SSCP) method, which allows DNA fragments that have been amplified with specific primers and PCR to be scanned rapidly for any sequence variation. The general principles of the method are described, as are the major factors that must be considered in developing an optimal SSCP strategy, namely length of the PCR fragment and the temperature of the gel run. Options for sample denaturing gel characteristics and detection of DNA fragments are discussed. In addition, several modifications are presented that have been developed for high-throughput mutational analysis. The application of these techniques to screen for mutations in the LDL receptor gene in patients with familial hypercholesterolemia are described.
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Affiliation(s)
- S E Humphries
- University College of London Medical School, Department of Medicine, The Rayne Institute, UK
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42
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Haddad L, Day LB, Attwood J, Povey S, Humphries SE, Day IN. Development of a microsatellite-based approach to co-segregation analysis of familial hypercholesterolaemic kindreds. Ann Hum Genet 1997; 61:497-506. [PMID: 9543550 DOI: 10.1046/j.1469-1809.1997.6160497.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Co-segregation studies based on a selection of intragenic restriction fragment length polymorphisms of the low density lipoprotein receptor (LDLR) gene have been used extensively both for research and diagnostic studies of familial hypercholesterolaemia (FH) families, because direct mutation screening remains complex. Here we describe the development and application of a more efficient approach to co-segregation studies based on highly informative dinucleotide and tetranucleotide repeats flanking the LDLR gene. A series of microsatellites (D19S391, D19S394, D19S221 and D19S179) were selected for study on the basis of linkage analysis in the CEPH families using intragenic polymorphisms for a TA repeat (exon 18) in the LDLR gene, and earlier data for a Pvu II polymorphism (intron 15). A physical map of the region of chromosome 19 also contributed to this selection. One marker in particular, D19S394, sited 150 kilobases telomeric to the gene, was extremely useful, displaying 90% heterozygosity, robust PCR of tetranucleotide repeats without stutter bands, and no recombination with the LDLR gene (theta = 0, LOD 68). Use of this marker in the families of twenty-three FH probands from Hampshire demonstrated co-segregation of the hyperlipidaemia phenotype with the LDLR gene region, except in one family with defective apolipoprotein B-100, and a family turning out to display familial combined hyperlipidaemia. This approach should facilitate the search for any families where FH does not co-segregate with the LDLR gene, and will enhance the repertoire of molecular diagnostic tools available for FH.
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Affiliation(s)
- L Haddad
- Department of Medicine, Rayne Institute, University College London Medical School
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43
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Abstract
Familial defective apoB-100 (R3500Q) [FDB (R3500Q)] is caused by a mutation in the apoB gene (2p23.24). Almost all individuals with this disorder are of European descent, and in almost all cases the mutation is on a chromosome with a rare haplotype (194) at the apoB locus, suggesting that all FDB (R3500Q) probands are descended from a common ancestor in whom the original mutation occurred. The distribution of the mutation is consistent with an origin in Europe 6000-7000 years ago. We have estimated the amount of recombination between the apoB gene and markers on chromosome 2 in 34 FDB (R3500Q) probands in whom the mutation is on a 194 haplotype. Significant linkage disequilibrium was found between the apoB gene and marker D2S220. We have identified three YACs that contain the apoB gene and D2S220. The shortest restriction fragment common to the three YACs that contained both loci was 240 kb long. No shorter fragments with both loci were identified. On the assumption that 1000 kb corresponds to 1 cM, we deduce that the recombination distance between D2S220 and the apoB gene is about 0.24 cM. Combining this value with the linkage disequilibrium observed between the two loci in the probands, we estimate that the ancestral mutation occurred about 270 generations ago. We postulate that the original mutation occurred in the common ancestor of living FDB (R3500Q) probands, who lived in Europe about 6750 years ago. The errors in this estimate are discussed.
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Affiliation(s)
- N B Myant
- MRC Lipoprotein Team, Royal Postgraduate Medical School, Hammersmith Hospital, London
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44
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O'Dell SD, Miller GJ, Cooper JA, Hindmarsh PC, Pringle PJ, Ford H, Humphries SE, Day IN. Apal polymorphism in insulin-like growth factor II (IGF2) gene and weight in middle-aged males. Int J Obes (Lond) 1997; 21:822-5. [PMID: 9376897 DOI: 10.1038/sj.ijo.0800483] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In 1474 healthy Caucasoid men aged 45-65 y, insulin-like growth factor II (IGF2) Apal AA homozygotes showed a mean body weight 4 kg lower than Apal GG homozygotes (77.6 +/- 10.9 kg vs 81.6 +/- 11.5 kg, P = 0.003) with heterozygotes (GA) intermediate (80.1 +/- 11.9 kg). The mean serum IGF-II concentration in 44 Apal AA individuals was significantly higher than in 48 Apal GG individuals (683.3 +/- 146.9 ng/ml vs 614.0 +/- 124.0 ng/ml, P = 0.01). An INS Pstl polymorphism showed no association with weight and it was also found to be in minimal linkage disequilibrium with the IGF2 Apal site (coefficient 0.016). The IGF2 Apal AA genotype is therefore associated with lower mean body weight but higher serum IGF-II concentrations than the GG genotype. Apal GG homozygotes incur a 1.67-fold risk of pathological Body Mass index (BMI) (> 30 kg/m2) compared with AA homozygotes.
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Affiliation(s)
- S D O'Dell
- Department of Medicine, University College London Medical School, Rayne Institute, London, UK
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45
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Humphries SE, Gudnason V, Whittall R, Day IN. Single-strand conformation polymorphism analysis with high throughput modifications, and its use in mutation detection in familial hypercholesterolemia. International Federation of Clinical Chemistry Scientific Division: Committee on Molecular Biology Techniques. Clin Chem 1997; 43:427-35. [PMID: 9068585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The identification of the specific mutation causing an inherited disease in a patient is the framework for the development of a rationale for therapy and of DNA-based tests for screening relatives. We present here a review of the single-strand conformational polymorphism (SSCP) method, which allows DNA fragments that have been amplified with specific primers and PCR to be scanned rapidly for any sequence variation. The general principles of the method are described, as are the major factors that must be considered in developing an optimal SSCP strategy, namely the length of the PCR fragment and the temperature of the gel run. Options for sample denaturing gel characteristics and detection of DNA fragments are discussed. In addition, several modifications are presented that have been developed for high-throughput mutational analysis. The application of these techniques to screen for mutations in the LDL receptor gene in patients with familial hypercholesterolemia are described.
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Affiliation(s)
- S E Humphries
- Department of Medicine, University College of London Medical School, Rayne Institute, UK.
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46
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Day IN. Polymerase chain reaction. Br J Hosp Med (Lond) 1997; 57:170-1. [PMID: 9166383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- I N Day
- Department of Medicine, University College of London Medical School
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47
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Day IN, Haddad L, O'Dell SD, Day LB, Whittall RA, Humphries SE. Identification of a common low density lipoprotein receptor mutation (R329X) in the south of England: complete linkage disequilibrium with an allele of microsatellite D19S394. J Med Genet 1997; 34:111-6. [PMID: 9039985 PMCID: PMC1050862 DOI: 10.1136/jmg.34.2.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Familial hypercholesterolaemia is commonly caused by mutations in the low density lipoprotein receptor (LDLR) gene and more than 300 different mutations have been described worldwide. Some mutations occur at relatively higher frequency in certain populations, reflecting both chance and demography, most evident in founder populations. As part of a study of kindreds of 78 probands from Southampton and south west Hampshire, we identified the same mutation (R329X) in 9/78 (11.5%) probands. In all (100%) of these probands, length allele 259nt of the 17 allele microsatellite D19S394, sited approximately 250 kilobases telomeric and 5' to the LDLR gene, was observed, although in the general population this allele has a prevalence of only 16.1%. A simple diagnostic assay for R329X was constructed in conjunction with more detailed family studies. Both the R329X and linked D19S394 allele also cosegregated with the FH phenotype within each kindred. Although R329X involves a CpG site, it is highly likely that the families are identical by descent for R329X, we surmise with a common ancestor within 500 to 1000 years, although the mutation is not restricted to this geographical area. This relationship illustrates that the linkage disequilibrium of gene LDLR with marker D19S394 will enable rapid recognition using D19S394 genotype of possible common FH mutation(s) within a cohort of FH patients from a particular locality or ethnic group.
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Affiliation(s)
- I N Day
- Department of Medicine, The Rayne Institute, University College of London Medical School, UK
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48
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Talmud PJ, Tamplin OJ, Heath K, Gaffney D, Day IN, Humphries SE. Rapid testing for three mutations causing familial defective apolipoprotein B100 in 562 patients with familial hypercholesterolaemia. Atherosclerosis 1996; 125:135-7. [PMID: 8831935 DOI: 10.1016/0021-9150(96)05838-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Abstract
A final common pathway has been devised for analysis of de novo mutation at any CpG site. Artificial restriction sites can be introduced in known DNA sequences by using either or both sense and antisense mismatched PCR primers. Sitting of the primers directly adjacent 5' and 3' to the CpG site yields a 52-bp PCR product, resulting from the sum of the two 25-mer oligonucleotides plus the two intervening bases (C and G), and also yields consistent digestion fragments. Three out of four possible four-base palindromes (TaqI, HHaI, and MspI) were investigated for mutations R329X and E80K in the human LDL receptor gene, and for mutations R395W and R612C, and TaqI site was forced using PCR in which both primers had 3' mismatched T. Both empirically and on theoretical grounds, Taq1 is the forced restriction site of choice. The approach has been adapted to the high-throughput microplate diagonal gel electrophoresis (MADGE) system for selective analysis of mutations at CpG sites, which may account for 20% of all single base variation in the human genome.
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Affiliation(s)
- S D O'Dell
- Department of Medicine, University College London Medical School, Rayne Institute, UK
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50
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Gudnason V, Day IN, Humphries SE. Use of the single strand conformation polymorphism method for rapid screening for mutations in the low density lipoprotein receptor gene in patients with familial hypercholesterolemia: effect on plasma lipid levels of different classes of mutations. Z Gastroenterol 1996; 34 Suppl 3:6-8. [PMID: 8767444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The single strand conformational polymorphism (SSCP) method was used to screen patients with familial hypercholesterolemia (FH) for mutations in the 3' part of exon 4 of the low density lipoprotein receptor (LDLR) gene. In 311 patients, six previously described mutations were identified in 29 apparently unrelated individuals (9.3%); three of the mutations are null alleles producing no protein, while the other three lead to production of a defective protein. In the patients where no mutation was detected mean total plasma cholesterol levels were 9.4 mmol/l, compared to 11.3 mmol/l in those individuals with a mutation creating a null allele, and 11.2 mmol/l in those with a mutation that resulted in the production of a defective protein (p < 0.001). These data reinforce observations of others that specific mutations in the LDL receptor gene are associated with different effects on plasma lipids, and indicate that the phenotype is influenced by the genotype.
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Affiliation(s)
- V Gudnason
- Dept Medicine, Rayne Institute, University College of London Medical School, UK
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