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1.
Am J Phys Anthropol ; 158(1): 43-54, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26118778

ABSTRACT

OBJECTIVE: Primates were common in North America through most of the Eocene, but vanished in the Chadronian, about 35 million years ago. In the Arikareean, about 6 million years later, the enigmatic primate Ekgmowechashala appeared in the Great Plains and Oregon. This taxon shows little resemblance to other North American primates and its phylogenetic position has long been debated. New material of this taxon allows a revised assessment of its age and how it is related to other primates. METHODS: Recently collected Ekgmowechashala specimens from the Turtle Cove Member of the John Day Formation in Oregon are described. These specimens are compared to previously collected material from South Dakota and Nebraska, as well as other fossil primates from North America and Asia. RESULTS: Study of the John Day material allows diagnosis of a new, distinct species. Comparison of Ekgmowechashala to a pair of recently described Asian primates, Muangthanhinius and Bugtilemur, suggests that it is a strepsirrhine adapiform, rather than an omomyid. The well-defined stratigraphy and dated marker beds of the Turtle Cove Member provide a refined age for Ekgmowechashala occurrences in Oregon, during the Oligocene (early Arikareean). CONCLUSIONS: The age and morphology of these ekgmowechashaline taxa suggest that the group originated in Asia and dispersed to North America in the Oligocene, after the extinction of other primates in North America. Contemporaneous occurrences of Ekgmowechashala in Oregon and the Great Plains indicate the last non-human primates vanished in North America about 26 million years ago.


Subject(s)
Biological Evolution , Fossils , Primates/anatomy & histology , Primates/physiology , Tooth/anatomy & histology , Animals , Anthropology, Physical , Oregon
2.
Int Urogynecol J ; 26(3): 401-6, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25352072

ABSTRACT

INTRODUCTION AND HYPOTHESIS: Understanding the clustering of pelvic floor disorders (PFDs) within families is important because it may suggest underlying risk factors that may be environmental, genetic or both. The objective of this study was to describe clinical characteristics observed in familial cases with PFDs and compare them with strictly defined controls. METHODS: Women evaluated and treated for PFDs were recruited as part of a larger genetic study. Here, we define familial cases as those with bothersome symptoms or treatment for a PFD (pelvic organ prolapse [POP], stress urinary incontinence [SUI], and overactive bladder [OAB]) and who had a first-degree relative with bothersome symptoms or treatment for the same pelvic floor defect. We assigned clinical characteristics to probands and their relatives using standardized symptom questions (PFDI), examination, and review of treatment records, if any. RESULTS: We identified 126 familial POP cases, 183 familial SUI cases, and 101 familial OAB cases. Familial cases were more likely to have bothersome symptoms for more than one PFD. Among familial POP cases, bothersome SUI (71 %), OAB (54 %), and a combination of all three disorders (48 %) were common. Among familial SUI cases, bothersome OAB (60 %), POP (59 %), and combinations of all disorders (40 %) were common. Among familial OAB cases, bothersome SUI (88 %), POP (66 %), and combinations of all three disorders (59 %) were common. CONCLUSIONS: Familial cases of POP, SUI, and OAB are more likely to have more than one pelvic floor defect. It is likely that underlying genetic factors contribute to more than one pelvic floor defect.


Subject(s)
Pelvic Organ Prolapse/genetics , Urinary Bladder, Overactive/genetics , Urinary Incontinence, Stress/genetics , Adult , Age of Onset , Body Mass Index , Case-Control Studies , Female , Humans , Joint Instability/complications , Middle Aged , Parity , Pelvic Organ Prolapse/complications , Phenotype , Striae Distensae/complications , Urinary Bladder, Overactive/complications , Urinary Incontinence, Stress/complications
3.
J Oncol ; 2010: 397632, 2010.
Article in English | MEDLINE | ID: mdl-20300555

ABSTRACT

Ewing's sarcoma is a highly malignant tumor of children and young adults. The molecular mechanisms that underlie Ewing's Sarcoma development are beginning to be understood. For example, most cases of this disease harbor somatic chromosomal translocations that fuse the EWSR1 gene on chromosome 22 with members of the ETS family. While some cooperative genetic events have been identified, such as mutations in TP53 or deletions of the CDKN2A locus, these appear to be absent in the vast majority of cases. It is therefore uncertain whether EWS/ETS translocations are the only consistently present alteration in this tumor, or whether there are other recurrent abnormalities yet to be discovered. One method to discover such mutations is to identify familial cases of Ewing's sarcoma and to then map the susceptibility locus using traditional genetic mapping techniques. Although cases of sibling pairs with Ewing's sarcoma exist, familial cases of Ewing's sarcoma have not been reported. While Ewing's sarcoma has been reported as a 2nd malignancy after retinoblastoma, significant associations of Ewing's sarcoma with classic tumor susceptibility syndromes have not been identified. We will review the current evidence, or lack thereof, regarding the potential of a heritable condition predisposing to Ewing's sarcoma.

4.
East Afr Med J ; 86(2): 51-4, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19894467

ABSTRACT

OBJECTIVE: This study seeks to find out the presentation, management and complications of encephaloceles in an African setting. DESIGN: a retrospective study reviewing the age and sex of the patients, type and contents of encephaloceles, associated anomalies, preoperative evaluation and investigations, surgical approaches, intra- and post-operative complications as well as follow-up outcomes. SETTING: Bethany Crippled Children's centre and Bethanykids at Kijabe Hospital (BKKH), between January 1998 and August 2006. PATIENTS: Of the 53 patients seen, 23 were males and 30 females. The median age at presentation was four months. RESULTS: The follow-up period extended to eight years. Twenty nine patients had occipital encephaloceles, and 39 were operated using the direct external approach. Cererobrospinal fluid leak was the most common post-operative complication. Recurrence occurred in four patients and death in six. CONCLUSIONS: Most of the encephalocele patients manage d at BKKH had good outcomes and proceeded to live normal or near-normal lives. Our study confirms that even in resource-constrained areas, children with encephaloceles can be successfully managed with acceptable outcomes.


Subject(s)
Encephalocele/diagnosis , Adolescent , Child , Child, Preschool , Encephalocele/chemically induced , Encephalocele/epidemiology , Encephalocele/surgery , Female , Humans , Infant , Infant, Newborn , Kenya/epidemiology , Male , Retrospective Studies , Risk Factors
5.
Proc Biol Sci ; 276(1672): 3505-11, 2009 Oct 07.
Article in English | MEDLINE | ID: mdl-19605396

ABSTRACT

Historically, ecomorphological inferences regarding theropod (i.e. 'predatory') dinosaurs were guided by an assumption that they were singularly hypercarnivorous. A recent plethora of maniraptoran discoveries has produced evidence challenging this notion. Here, we report on a new species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative completeness of this specimen permits a phylogenetic reassessment of Therizinosauria-the theropod clade exhibiting the most substantial anatomical evidence of herbivory. In the most comprehensive phylogenetic study of the clade conducted to date, we recover Therizinosauria as the basalmost maniraptoran lineage. Using concentrated changes tests, we present evidence for correlated character evolution among herbivorous and hypercarnivorous taxa and propose ecomorphological indicators for future interpretations of diet among maniraptoran clades. Maximum parsimony optimizations of character evolution within our study indicate an ancestral origin for dietary plasticity and facultative herbivory (omnivory) within the clade. These findings suggest that hypercarnivory in paravian dinosaurs is a secondarily derived dietary specialization and provide a potential mechanism for the invasion of novel morpho- and ecospace early in coelurosaurian evolution-the loss of obligate carnivory and origin of dietary opportunism.


Subject(s)
Biological Evolution , Dinosaurs/anatomy & histology , Dinosaurs/genetics , Feeding Behavior/physiology , Animals , North America , Paleontology
6.
Ann Hum Genet ; 72(Pt 2): 279-87, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18093282

ABSTRACT

We examine the utility of high density genotype assays for predisposition gene localization using extended pedigrees. Results for the distribution of the number and length of genomic segments shared identical by descent among relatives previously derived in the context of genomic mismatch scanning are reviewed in the context of dense single nucleotide polymorphism maps. We use long runs of loci at which cases share a common allele identically by state to localize hypothesized predisposition genes. The distribution of such runs under the hypothesis of no genetic effect is evaluated by simulation. Methods are illustrated by analysis of an extended prostate cancer pedigree previously reported to show significant linkage to chromosome 1p23. Our analysis establishes that runs of simple single locus statistics can be powerful, tractable and robust for finding DNA shared between relatives, and that extended pedigrees offer powerful designs for gene detection based on these statistics.


Subject(s)
Chromosome Mapping/methods , Genetic Predisposition to Disease/genetics , Genetic Testing/methods , Genomics/methods , Polymorphism, Single Nucleotide/genetics , Computer Simulation , Genotype , Humans , Pedigree
7.
Exp Clin Endocrinol Diabetes ; 115(10): 634-40, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18058597

ABSTRACT

The aims of this study were to estimate relative risk for type 1 and type 2 diabetes in relatives of diabetic patients, and to test for excess relatedness among diabetic patients. Additionally, the difference in parental transmission of diabetes was investigated. This study used a unique Utah genealogical resource, linked to electronic medical records of the largest health provider in Utah. We identified 19,640 patients with a diagnosis of type 1 or type 2 diabetes. Relative Risks (RRs) for type 1 and type 2 diabetes were assessed for first-, second- and third-degree relatives of diabetic patients. The observed average relatedness of diabetic patients was compared to the expected relatedness using the Genealogical Index of Familiality (GIF). We observed significantly elevated RRs for type 1 diabetes in first-degree (RR=8.68; P<0.0001), second-degree (RR=1.93; P<0.0001) and third-degree relatives (RR=1.74; P<0.0001) of type 1 diabetic patients. RRs for type 2 diabetes were significantly increased in first-degree (RR=2.24; P<0.0001), second-degree (RR=1.36; P<0.0001) and third-degree relatives (RR=1.14; P<0.0001) of type 2 diabetic patients. Significantly increased RRs for type 1 diabetes were observed in the relatives of type 2 diabetic patients, and vice versa. The GIF analysis showed significant excess relatedness for type 1 diabetes cases, and independently for type 2 diabetes cases. Offspring of diabetic fathers were at significantly higher risk for type 1 diabetes than offspring of diabetic mothers (RR=9.73; P<0.0001 compared to RR=4.99; P<0.0001). No significant difference in parental transmission was observed for type 2 diabetes. Our results strongly support the existence of a genetic contribution to both type 1 and type 2 diabetes, and additionally suggest a relationship between both types of diabetes. Furthermore, our results suggest a significant difference in parental transmission of type 1 diabetes.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 2/genetics , Adolescent , Adult , Aged , Databases, Factual , Family , Female , Humans , Male , Middle Aged , Pedigree , Risk , Risk Factors , Utah
8.
Prostate ; 67(6): 605-13, 2007 May 01.
Article in English | MEDLINE | ID: mdl-17299800

ABSTRACT

BACKGROUND: It has been proposed that studying alternative phenotypes, such as tumor aggressiveness, may be a solution for overcoming the apparent heterogeneity that has hindered the identification of prostate cancer (PC) genes. We present the results of a genome-scan for predisposition to aggressive PC using the Utah high-risk pedigree resource. METHODS: We identified 259 subjects with aggressive PC in 57 extended and nuclear families. Parametric and non-parametric multipoint linkage statistics were calculated for a genome-wide set of 401 microsatellite markers using the MCLINK software package. Stratification analyses by the number of affected subjects per pedigree (<5, >or=5) and the average age at diagnosis of affected subjects (<70 years, >or=70 years) were also performed. RESULTS: No significant results were observed at the genome-wide level, but suggestive evidence for linkage was observed on chromosomes 9q (HLOD = 2.04) and 14q (HLOD = 2.08); several pedigrees showed individual evidence for linkage at each locus (LOD > 0.58). The subset of pedigrees with earlier age at onset demonstrated nominal linkage evidence on chromosomes 3q (HLOD = 1.79), 8q (HLOD = 1.67), and 20q (HLOD=1.82). The late-onset subset showed suggestive linkage on chromosome 6p (HLOD = 2.37) and the subset of pedigrees with fewer than five affected subjects showed suggestive linkage on chromosome 10p (HLOD = 1.99). CONCLUSIONS: Linkage evidence observed on chromosomes 6p, 8q, and 20q support previously reported PC aggressiveness loci. While these results are encouraging, further research is necessary to identify the gene or genes responsible for PC aggressiveness and surmount the overarching problem of PC heterogeneity.


Subject(s)
Genetic Linkage , Genetic Predisposition to Disease , Genome, Human , Prostatic Neoplasms/genetics , Aged , DNA, Neoplasm/analysis , Genotype , Humans , Lod Score , Male , Microsatellite Repeats , Middle Aged , Pedigree , Prostatic Neoplasms/epidemiology , Utah/epidemiology
9.
Am J Med Genet A ; 137A(3): 269-75, 2005 Sep 01.
Article in English | MEDLINE | ID: mdl-16096997

ABSTRACT

Isolate populations of varied types have proven powerful for gene identification for rare Mendelian disorders, and continue to show such promise for more complex phenotypes. Existing isolate populations are limited in the phenotypes available for study, and new population isolates are unlikely to arise. We utilize genealogical data available for the state of Utah, dating back to its European founders, to retrospectively define and examine pseudo-isolate subpopulations. These pseudo-isolate populations are defined by selection of a set of "founders" from the genealogical data, and then limitation of "immigration" by censoring of matings and offspring that do not match the isolate population design. A wide variety of pseudo isolate and other study designs are possible by varying the number and type of founders and the extent of immigration allowed. We present several different example Birth-Country pseudo-isolate populations defined within the Utah Population Database (UPDB). We utilize linked cancer phenotype data available for the Utah population to show the utility of this pseudo-isolate approach for identification of more genetically homogeneous prostate cancer pedigrees for predisposition gene identification. In conclusion, we present a unique approach to retrospective "creation" of isolate populations using existing genealogical data. We use the UPDB to exhibit the utility of this approach for the highly heterogeneous Utah population, and suggest the approach is feasible for any population for which high quality genealogy and phenotype data are available.


Subject(s)
Genetics, Population , Pedigree , Databases as Topic/statistics & numerical data , Female , Founder Effect , Humans , Male , Neoplasms/genetics , Selection, Genetic , Utah
10.
Adv Space Res ; 34(7): 1502-8, 2004.
Article in English | MEDLINE | ID: mdl-15846879

ABSTRACT

The cost of keeping people alive in space is assessed from a theoretical viewpoint and using two actual designs for plant growth systems. While life support is theoretically not very demanding, our ability to implement life support is well below theoretical limits. A theoretical limit has been calculated from requirements and the state of the art for plant growth has been calculated using data from the BIO-Plex PDR and from the Cornell CEA prototype system. The very low efficiency of our current approaches results in a high mission impact, though we can still see how to get a significant reduction in cost of food when compared to supplying it from Earth. Seeing the distribution of costs should allow us to improve our current designs.


Subject(s)
Agriculture/economics , Ecological Systems, Closed , Life Support Systems/economics , Space Flight/economics , Agriculture/methods , Atmospheric Pressure , Cost-Benefit Analysis , Extraterrestrial Environment , Facility Design and Construction , Humans , Mars , Plants, Edible/growth & development , Radiation Protection , Spacecraft/economics
11.
Trans ASAE ; 45(1): 215-21, 2002.
Article in English | MEDLINE | ID: mdl-12442766

ABSTRACT

A decision model is presented that compares lighting systems for a plant growth scenario and chooses the most appropriate system from a given set of possible choices. The model utilizes a Multiple Attribute Utility Theory approach, and incorporates expert input and performance simulations to calculate a utility value for each lighting system being considered. The system with the highest utility is deemed the most appropriate system. The model was applied to a greenhouse scenario, and analyses were conducted to test the model's output for validity. Parameter variation indicates that the model performed as expected. Analysis of model output indicates that differences in utility among the candidate lighting systems were sufficiently large to give confidence that the model's order of selection was valid.


Subject(s)
Decision Making, Computer-Assisted , Environment, Controlled , Light , Lighting/instrumentation , Models, Biological , Plant Development , Ecological Systems, Closed , Evaluation Studies as Topic , Lactuca/growth & development , Lactuca/radiation effects , Life Support Systems/instrumentation , Plants/radiation effects , Software , Systems Theory
12.
J Pers Soc Psychol ; 81(5): 910-21, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11708566

ABSTRACT

The desire to create a particular impression of oneself to others is a fundamental interpersonal motive that should be followed by an assessment of the success of the self-presentation. The authors integrate the areas of self-presentation and metaperception in the present research by assigning participants to enact roles during 2 dyadic interactions and measuring the actors' metaperceptions and their partners' trait judgments. They found a high level of accuracy in actors' metaperceptions but no accuracy in partners' trait judgments of the actors. Instead, partners' trait judgments corresponded closely to the actors interpersonal behavior, indicating that there was little or no "personality leakage" in the actors' behavior. Random assignment to role created a situation in which private self was uncorrelated with public self. Results indicate that actors were able to disregard their self-concepts when determining the impressions they created.


Subject(s)
Social Behavior , Social Perception , Affect , Deception , Facial Expression , Humans , Interpersonal Relations , Judgment , Random Allocation
13.
Clin Exp Allergy ; 31(5): 756-60, 2001 May.
Article in English | MEDLINE | ID: mdl-11422135

ABSTRACT

BACKGROUND: Asthma is becoming increasingly prevalent and a number of research groups are investigating its genetic and environmental basis. OBJECTIVE: To produce a brief screening tool suitable for determining phenotype in asthma research. METHODS: The scores from eight questions on symptoms and history were obtained from 678 adults and 244 children from high asthma-incidence caucasian families. An independent physician diagnosis was also obtained with the use of a modified NHLBI-CSGA questionnaire and pulmonary function test. Stepwise logistic regression was applied to determine which of the eight questions had greatest predictive value for asthma, and the quality of the resultant models was evaluated using an independent set of 643 adults and 239 children. RESULTS: For adults, the most parsimonious model used responses from three of the eight questions. It had sensitivity and specificity of 0.94 and 0.96, respectively. For children, responses to two questions gave a model with sensitivity and specificity of 0.97. For both age groups, negative predictive values were above 0.87. Positive predictive values were 0.58 and 0.78 for adults and children respectively. The latter emphasize the need for conformation, by physician, of "affected" calls made by this initial screen. CONCLUSION: The brief questionnaires described are potentially useful in a research setting, as a preliminary screening mechanism of low cost. Their use will reduce the numbers of subjects that must undergo detailed phenotyping.


Subject(s)
Asthma/diagnosis , Adolescent , Adult , Aged , Asthma/epidemiology , Asthma/genetics , Child , Child, Preschool , Female , Humans , Incidence , Male , Middle Aged , Predictive Value of Tests , Sensitivity and Specificity , Spirometry/methods , White People
14.
Nat Genet ; 27(2): 172-80, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11175785

ABSTRACT

It is difficult to identify genes that predispose to prostate cancer due to late age at diagnosis, presence of phenocopies within high-risk pedigrees and genetic complexity. A genome-wide scan of large, high-risk pedigrees from Utah has provided evidence for linkage to a locus on chromosome 17p. We carried out positional cloning and mutation screening within the refined interval, identifying a gene, ELAC2, harboring mutations (including a frameshift and a nonconservative missense change) that segregate with prostate cancer in two pedigrees. In addition, two common missense variants in the gene are associated with the occurrence of prostate cancer. ELAC2 is a member of an uncharacterized gene family predicted to encode a metal-dependent hydrolase domain that is conserved among eukaryotes, archaebacteria and eubacteria. The gene product bears amino acid sequence similarity to two better understood protein families, namely the PSO2 (SNM1) DNA interstrand crosslink repair proteins and the 73-kD subunit of mRNA 3' end cleavage and polyadenylation specificity factor (CPSF73).


Subject(s)
Chromosomes, Human, Pair 17/genetics , Neoplasm Proteins/genetics , Prostatic Neoplasms/genetics , Amino Acid Sequence , Cloning, Molecular/methods , DNA, Complementary/genetics , Founder Effect , Genetic Linkage , Genetic Predisposition to Disease , Genotype , Humans , Male , Molecular Sequence Data , Mutation, Missense , Pedigree , RNA, Messenger/genetics , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Utah
15.
Curr Protoc Mol Biol ; Chapter 7: Unit7.4A, 2001 May.
Article in English | MEDLINE | ID: mdl-18265267

ABSTRACT

In the basic dideoxy sequencing reaction, an oligonucleotide primer is annealed to a single-stranded DNA template and extended by DNA polymerase in the presence of four deoxyribonucleoside triphosphates (dNTPs), one of which is 35S-labeled. The reaction also contains one of four dideoxyribonucleoside triphosphates (ddNTPs), which terminate elongation when incorporated into the growing DNA chain. After completion of the sequencing reactions, the products are subjected to electrophoresis on a high-resolution denaturing polyacrylamide gel and then autoradiographed to visualize the DNA sequence. Three variations of the dideoxy sequencing procedure are currently in use and are presented in this unit. In the "labeling/termination" procedure, primer chains are initially extended and labeled in the absence of terminating ddNTPs, whereas in the traditional "Sanger" procedure, labeling and termination of primer chains occur in a single step. A recent variation of the dideoxy sequencing method is thermal cycle sequencing in which the reaction mixture, containing template DNA, primer, thermostable DNA polymerase, dNTPs, and ddNTPs, is subjected to repeated rounds of denaturation, annealing, and elongation steps. The resulting linear amplification of the sequencing products allows much less template DNA to be used and eliminates independent primer annealing and template denaturation steps, which are required for the labeling/termination or Sanger procedures. The use of automated fluorescent sequencers for four-color dideoxy DNA sequencing is also described in detail.


Subject(s)
Base Sequence , DNA/chemistry , Dideoxynucleotides/chemistry , Automation , DNA Primers , Indicators and Reagents , Taq Polymerase , Templates, Genetic
16.
Curr Protoc Mol Biol ; Chapter 7: Unit7.6, 2001 May.
Article in English | MEDLINE | ID: mdl-18265270

ABSTRACT

The accuracy of DNA sequence determination depends largely upon resolution of the sequencing products in denaturing polyacrylamide gels. This unit provides a detailed description of the setup, electrophoresis, and processing of such gels. In general, the gels required for DNA sequencing are 40-cm long, of uniform thickness, and contain 4% to 8% acrylamide and 7 M urea. Modifications of this protocol increase the length of readable sequence information which can be obtained from a single gel (i.e., forming the gel with wedge-shaped spacers to create a field gradient, or incorporating a buffer gradient, an electrolyte gradient, or an acrylamide step gradient into the gel). A modification to the Basic Protocol--inclusion of formamide in the sequencing gel--is designed to overcome gel compressions arising from secondary structure in the sequencing products during gel electrophoresis. A discussion of acrylamide concentrations and electrophoresis conditions is included in the Commentary.


Subject(s)
Base Sequence , DNA/chemistry , Electrophoresis, Polyacrylamide Gel/methods , Gels , Indicators and Reagents , Nucleic Acid Denaturation , Sensitivity and Specificity
17.
Curr Protoc Hum Genet ; Appendix 3: Appendix 3F, 2001 May.
Article in English | MEDLINE | ID: mdl-18428223

ABSTRACT

Polyacrylamide gels that contain a high concentration of urea as a denaturant are capable of resolving short (<500 nucleotides) single-stranded fragments of DNA or RNA that differ in length by as little as one nucleotide. Such gels are commonly used for DNA sequence analysis, as well as in PCR amplification of SSLPs (simple sequence length polymorphisms) for genotyping, genotyping by the ligase chain reaction (LCR), analysis of mutations by RNase A cleavage, chemical cleavage of heteroduplex DNA to identify mutations, and molecular analysis of fragile X syndrome by PCR. This appendix presents a protocol for the pouring, running, and processing of a typical gel which is 40-cm long with a uniform thickness of 0.4 mm, containing 7 M urea and 4% to 8% acrylamide.


Subject(s)
Electrophoresis, Polyacrylamide Gel/methods , Genetic Techniques , DNA/genetics , DNA/isolation & purification , Genetics, Medical , Humans , Nucleic Acid Denaturation , RNA/genetics , RNA/isolation & purification
18.
Genet Epidemiol ; 21 Suppl 1: S461-6, 2001.
Article in English | MEDLINE | ID: mdl-11793719

ABSTRACT

We describe an alternative nonparametric linkage (NPL) statistic to that of Kruglyak et al. [Am. J. Hum. Genet. 58:1347-63, 1996] that can be used with qualitative phenotypes, and is easily extended for use with quantitative phenotypes. We analyzed the Genetic Analysis Workshop 12 simulated isolated population data, replicate 1, using two phenotypes; affected status (AFF) a dichotomous phenotype and quantitative trait Q5, which was chosen since it was the most strongly associated with AFF. One false positive significant NPL score was observed for the AFF phenotype. For Q5 a single region on chromosome 1 reached genome-wide significance. The peak of this signal was for marker D01G137 at 135.1 cM with a quantitative trait locus (QTL)-NPL score of 4.19. The nearest marker to the true location of the major gene (MG5 at 137.1 cM) was D01G139 at position 135.8 cM, where the QTL-NPL score was still high at 4.08.


Subject(s)
Chromosome Mapping/statistics & numerical data , Models, Genetic , Phenotype , Quantitative Trait, Heritable , Statistics, Nonparametric , Genetic Predisposition to Disease , Genotype , Humans
19.
Genet Epidemiol ; 21 Suppl 1: S492-7, 2001.
Article in English | MEDLINE | ID: mdl-11793725

ABSTRACT

Classical parametric two-point linkage analysis is a powerful analysis tool, however there are clear disadvantages too, including the sensitivity to allele frequency mis-specification. Conversely, multipoint linkage analysis is not sensitive to allele frequency mis-specification, but it is sensitive to genetic model mis-specification. Göring and Terwilliger [Am J Hum Genet 66:1095-106, 2000] proposed a new robust multipoint statistic that increased the robustness of multipoint analyses. In this paper we have referred to this new statistic as the tlod. We applied this new statistic to the Genetic Analysis Workshop (GAW) 12 data using affected status (AFF) as the phenotype of interest. The heterogeneity tlod and two-point hlod scores correlated highly across the genome (p < 0.0001), as expected, but the het-tlod had a lower number false positives. In addition, the tlod analysis handled missing data better, as would be expected for a multipoint method. When one-third of the genotype data was removed (dead people) the tlod analysis was less affected than the two-point analysis. When tlod scores were compared with multipoint lod scores in true gene locations, the robustness of the tlod to model mis-specification was clearly evident. When the "best" replicate from the general population was analyzed, a borderline genome-wide significant two-point hlod result (3.6) was found 4 cM from MG6 and MG7 on chromosome 6. The heterogeneity tlod score was lower than the two-point hlod score (1.8), but greater than the heterogeneity multipoint lod score (0.4). However, when replicate 1 of the isolated population was analyzed none of the true gene locations were identified with either statistic.


Subject(s)
Chromosome Mapping/statistics & numerical data , Lod Score , Models, Genetic , Quantitative Trait, Heritable , Chromosomes, Human, Pair 10 , Genetic Markers/genetics , Genetics, Population , Genotype , Haplotypes/genetics , Humans , Markov Chains , Phenotype , Polymorphism, Single Nucleotide/genetics
20.
Genet Epidemiol ; 21 Suppl 1: S571-5, 2001.
Article in English | MEDLINE | ID: mdl-11793740

ABSTRACT

We subjected the first replication of the simulated isolated population data set to a novel analysis for association between marker alleles and either disease phenotypes or quantitative variable. The analysis depends on being able to reliably reconstruct all haplotypes in the pedigree. This was achieved using the MCLINK blocked Gibbs sampling program. We observed a highly significant association between the variable Q5 and marker D01G138, and suggestive associations between the disease trait and markers D03G056 and D07G004.


Subject(s)
Alleles , Chromosome Mapping/statistics & numerical data , Haplotypes/genetics , Models, Genetic , Pedigree , Genetic Markers/genetics , Genetic Predisposition to Disease/genetics , Genetics, Population , Humans , Likelihood Functions , Lod Score , Mathematical Computing , Middle Aged , Phenotype , Quantitative Trait, Heritable , Software
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