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Flashcards in Genetics flash Deck (47)
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31

HDAC

histone de-acetylase, deacetylated histones to pack them tightly together

32

Genomic imprinting

Parent derived chromosomes are epigenetically marked (imprinted = turned off)

33

Prader-Willi syndrome

Microdeletion of paternal chromosome, maternal chromosome has genomic imprinting. Paternal deletion results in no active genes. Sym: short, mental retardation, hypogonadism, emotional lability, unregulated appetite

34

Angelman Syndrome

Microdeletion of chromosome that is maternally imprinted. Sym: Microcephaly, seizures, emotional exuberance, attnetion problems, motor problems

35

Multifactorial disorders

Phenotype is affected by genotype and enviromental factors. Ex: obesity, Diabetes type 2, atherosclerotic heart disease

36

Threshold model

Underlying genetic liability distribution in population which must be reached for phenotype to be seen

37

Concordance study in twins

Measure hereitability of disease (1= one twin has it the other twin has 100% chance of having it)

38

Monozygotic twin

genetically identical

39

Dizygotic twin

share 50% of chromosome (like siblings)

40

Enviromental factors

outdoor, indoor, occupational, consumption

41

Barker hypothesis

Adverse events in fetal life and early childhood establish increased risk of disease in adult life

42

Sensitivity

Proportion of true positives accurately detected = true positive/ (true pos. + false neg.)

43

Specificity

Proportion of true negatives accurately detected = true neg./ (false pos. + true neg)

44

Positive predictive value

Portion of those that are actually positive who test positive = true pos./ (true + false positive)

45

Negative predictive value

Portion of those who are actually negative that test negative = true neg. / (true + false negative)

46

Loss of heterozygosity

2nd mutation (often gross event) leading to both alleles being mutated (1st is often inherited or somatic)

47

Knudsen's 2 hit hypothesis

1) 1st is inherited, 2nd is gross chromosomal change 2) normal --> very rare 1st event, frequent 2nd event