Genetics_Flash_Cards1.csv

rare mutations -> large deleterious effects; common mutations have smaller effect and milder phenotype

phenotype = genotype + environment

the fraction of variation in phenotype that can be explained by genetic factors; NOT static - can vary within populations and over time

occurring in more members of a particular family than one would expect by random chance. Correlation tied to degree of relatedness?

tests whether observedfamily data fit with predicted patterns; goal = determination of inheritance patterns

refers to the proportion of people with a specific allele who exhibit clinical symptoms; not everyone with the disease phenotype have the disease genotype

mutations in different genes can lead to the same phenotype (opposite of variable expressivity)

involves staining and analysis of chromosomes

fluorescence in situ hybridization; probes for specific sequences on chromosomes; useful for detecting chromosomal abnormalities or large deletions or unbalanced translocation; uses very large probes

variable nucleotide tandem repeat (10s-100s base pair replications); can be used as a genetic marker; used in DNA 'fingerprinting'

short tandem repeats (2-4 nucleotides per repeat); can be used as a genetic marker; also called microsatellites

single nucleotide polymorphism; can be used as a genetic marker

uses fluorescently labeled dedeoxynucleotides to mark position of specific nucleotides in the genome -> sequencing (put results all together)

single base pair change

no change in amino acid (but could affect splicing)

substitutes one amino acid for another

changes an amino acid into a premature stop codon

changes the reading frame of a gene; results in translation of different amino acids

comparative genome hybridization; involves array of probes; compares patient DNA to control DNA; able to detect deletions and duplications

creation of a genetic map assigning DNA fragments to chromosomes; utilizes gene linkage; utilizes genetic markers

triangular plot that measures linkage of specific sections of DNA to each other

generally = case-control studies; look at association between genetic markers (SNPs) and allele frequency in case vs. control populations; odds ratio describes strength of association

candidate-gene and genome-wide association study

type of association study in which researchers look at the frequency of specific genes that are suspected to have biological functions related to disease

genome-wide association study; hypothesis-free study that looks at association between genetic markers and alleles in diseased population across the genome

ancestry-informative markers; use sample SNP data to determine ancestry of study participants; method of controlling for population stratification

method of controlling for population stratification; involves division of observed test statistic by a certain value (derived from observing other loci in the population that are not suspected to be linked with the allele in question)

transmission disequilibrium test; type of analysis for family-based association testing; number of parents who pass on suspected disease-causing allele to affected child is compared to the number of parents who pass on non-disease-causing allele to affected child

can reveal systematic error such as genotyping or population stratification error; deviation from chi-square values under the null hypothesis indicate systematic error

Bonferroni test; permutation tests

states that common traits are most likely the result of common (& therefore old) genetic variation

random fluctuation in allele frequencies due to chance variations; has more noticable effect in smaller populations

members of a population tend to have children with other members of that population

an environmental force increases the fitness of an allele

refers to the ability of the allele to be passed on; does NOT necessarily mean that allele is beneficial

older technique that uses the principles of nucleic acid hybridization to detect and determine the size of specific fragments of DNA

similar to a Southern blot; detects RNA instead of DNA

places in the genome at which there is known to be variation in copy number between individuals

protein structure that forms between homologous chromosomes during prophase I; mediates chromosome pairing and recombination

the physical bridge formed between chromosomes at the recombination site; tether homologs and maintain proper alignment; hold bivalent at meiotic plate until anaphase

stable and heritable mitotic and/or meiotic changes in gene expression that do not entail a change in DNA sequence

constitutive is always inactive; facultative is active in some cells (euchromatin) and inactive in others (heterochromatin)

regions of DNA that contain many CG repeats; are sites of methylation

immediately after fertilization - paternal X chromosome inactivated; facilitated by Xist; after inner cell mass forms all markings are erased; in each cell one of the X chromosomes (selected at random) is inactivated via Xist; some genes on the chromosome may still be active

usually the active X; become unbalanced in progeny and are inactivated; may partially inactivate autosome

caused by paternal imprinting; paternal gene epigenetically silenced while there is a deleterious mutation on the maternal gene

caused by maternal imprinting; maternal gene epigenetically silenced while there is a deleterious mutation on the paternal gene

occurs when a child receives two copies of a chromosome from one parent; can lead to Prader-Willis if two maternally imprinted genes are passed on; can lead to Angelman syndrome if two paternally imprinted genes are passed on

occurs when one chromosome is lost after a nondisjunction effect; can lead to parental disomy if two remaining chromosomes are from the same parent

diseases due to epigenetic changes (inappropriately inactivated genes)

diseases due to defects in interpretation of the epigenetic code (mutation of proteins that bind methylated histones/DNA)

in mitochindria - presence of both mutant and normal DNA

in mitochondria - refers to the idea that heteroplasmic cells may produce daughter cells with higher or lower proportions of mutant DNA (random segregation)

self-sustaining growth signals; insensitivity to anti-growth factors; angiogenesis; immortality; inhibition of apoptosis; metastasis & tissue invasion

a diagram illustrating one theory of tumor formation; updated Vogelgram incorperates idea of driver & passenger mutations

about 1.6% of genes show recurrent somatic mutations that appear to be indicated with cancer development; mutations in about 10% of these genes are found in the germline

about 90% = dominant (oncogenes) - more constrained repertoire of mutations; 10% = recessive (tumor suppressor genes) - wide range of mutations

closing of skull sutures; involves FGFR2 gene; overactivation can lead to premature closing of sutures; alternative splicing of FGF2 in different tissues can lead to different phenotypes