Genetic Phenomena Commons^™

Multipoint Genome-Wide Linkage Scan For Nonword Repetition In A Multigenerational Family Further Supports Chromosome 13q As A Locus For Verbal Trait Disorders, D. T. Truong, L. D. Shriberg, S. D. Smith, K. L. Chapman, A. R. Scheer-Cohen, M. M.C. Demille, A. K. Adams, Alejandro Q. Nato Jr., E. M. Wijsman, J. D. Eicher, J. R. Gruen

Biochemistry and Microbiology

Verbal trait disorders encompass a wide range of conditions and are marked by deficits in five domains that impair a person’s ability to communicate: speech, language, reading, spelling, and writing. Nonword repetition is a robust endophenotype for verbal trait disorders that is sensitive to cognitive processes critical to verbal development, including auditory processing, phonological working memory, and motor planning and programming. In the present study, we present a six-generation extended pedigree with a history of verbal trait disorders. Using genome-wide multipoint variance component linkage analysis of nonword repetition, we identified a region spanning chromosome 13q14–q21 with LOD = 4.45 between …

Genetic Candidate Variants In Two Multigenerational Families With Childhood Apraxia Of Speech, Peter Beate, Ellen M. Wijsman, Alejandro Q. Nato Jr., University Of Washington Center For Mendelian Genomics, Mark M. Matsushita, Kathy L. Chapman, Ian B. Stanaway, John Wolff, Kaori Oda, Virginia B. Gabo, Wendy H. Raskind

Biochemistry and Microbiology

Childhood apraxia of speech (CAS) is a severe and socially debilitating form of speech sound disorder with suspected genetic involvement, but the genetic etiology is not yet well understood. Very few known or putative causal genes have been identified to date, e.g., FOXP2 and BCL11A. Building a knowledge base of the genetic etiology of CAS will make it possible to identify infants at genetic risk and motivate the development of effective very early intervention programs. We investigated the genetic etiology of CAS in two large multigenerational families with familial CAS. Complementary genomic methods included Markov chain Monte Carlo linkage …

Estimating Relationships Between Phenotypes And Subjects Drawn From Admixed Families., Elizabeth M. Blue, Lisa A. Brown, Matthew P. Conomos, Jennifer L. Kirk, Alejandro Q. Nato Jr., Alice B. Popejoy, Jesse Raffa, John Ranola, Ellen M. Wijsman, Timothy Thornton

Biochemistry and Microbiology

Background: Estimating relationships among subjects in a sample, within family structures or caused by population substructure, is complicated in admixed populations. Inaccurate allele frequencies can bias both kinship estimates and tests for association between subjects and a phenotype. We analyzed the simulated and real family data from Genetic Analysis Workshop 19, and were aware of the simulation model.

Results: We found that kinship estimation is more accurate when marker data include common variants whose frequencies are less variable across populations. Estimates of heritability and association vary with age for longitudinally measured traits. Accounting for local ancestry identified different true associations …

Identity-By-Descent Estimation With Population- And Pedigree-Based Imputation In Admixed Family Data, Mohamad Saad, Alejandro Q. Nato Jr., Fiona L. Grimson, Steven M. Lewis, Lisa A. Brown, Elizabeth M. Blue, Timothy A. Thornton, Elizabeth A. Thompson, Ellen M. Wijsman

Biochemistry and Microbiology

Background: In the past few years, imputation approaches have been mainly used in population-based designs of genome-wide association studies, although both family- and population-based imputation methods have been proposed. With the recent surge of family-based designs, family-based imputation has become more important. Imputation methods for both designs are based on identity-by-descent (IBD) information. Apart from imputation, the use of IBD information is also common for several types of genetic analysis, including pedigree-based linkage analysis.

Methods: We compared the performance of several family- and population-based imputation methods in large pedigrees provided by Genetic Analysis Workshop 19 (GAW19). We also evaluated the …

Rgs16, A Novel P53 And Prb Cross-Talk Candidate Inhibits Migration And Invasion Of Pancreatic Cancer Cells, Miranda B. Carper, James Denvir, Goran Boskovic, Donald A. Primerano, Pier Paolo Claudio

Biochemistry and Microbiology

Data collected since the discovery of p53 and pRb/RB1 suggests these tumor suppressors cooperate to inhibit tumor progression. Patients who have mutations in both p53 and RB1 genes have increased tumor reoccurrence and decreased survival compared to patients with only one tumor suppressor gene inactivated. It remains unclear how p53 and pRb cooperate toward inhibiting tumorigenesis. Using RNA expression profiling we identified 179 p53 and pRb cross-talk candidates in normal lung fibroblasts (WI38) cells exogenously coexpressing p53 and pRb. Regulator of G protein signaling 16 (RGS16) was among the p53 and pRb cross-talk candidates and has been implicated in inhibiting …

Mapping Genes With Longitudinal Phenotypes Via Bayesian Posterior Probabilities, Anthony Musolf, Alejandro Q. Nato Jr., Douglas Londono, Lisheng Zhou, Tara C. Matise, Derek Gordon

Biochemistry and Microbiology

Most association studies focus on disease risk, with less attention paid to disease progression or severity. These phenotypes require longitudinal data. This paper presents a new method for analyzing longitudinal data to map genes in both population-based and family-based studies. Using simulated systolic blood pressure measurements obtained from Genetic Analysis Workshop 18, we cluster the phenotype data into trajectory subgroups. We then use the Bayesian posterior probability of being in the high subgroup as a quantitative trait in an association analysis with genotype data. This method maintains high power (>80%) in locating genes known to affect the simulated phenotype …

Truncation Of Type Iv Pilin Induces Mucoidy In Pseudomonas Aeruginosa Strain Pao579, T. Ryan Withers, F. Heath Damron, Yeshi Yin, Hongwei D. Yu

Biochemistry and Microbiology

Pseudomonas aeruginosa is a Gram negative, opportunistic pathogen that uses the overproduction of alginate, a surface polysaccharide, to form biofilms in vivo. Overproduction of alginate, also known as mucoidy, affords the bacterium protection from the host's defenses and facilitates the establishment of chronic lung infections in individuals with cystic fibrosis. Expression of the alginate biosynthetic operon is primarily controlled by the alternative sigma factor AlgU (AlgT/σ²²). In a nonmucoid strain, AlgU is sequestered by the transmembrane antisigma factor MucA to the cytoplasmic membrane. AlgU can be released from MucA via regulated intramembrane proteolysis by proteases AlgW and MucP …