Genetics and Pedigree Analysis Flashcards Preview

Cell: Exam 3 > Genetics and Pedigree Analysis > Flashcards

Flashcards in Genetics and Pedigree Analysis Deck (72):
0

Science that deals with heredity and variation in organisms, including the genetic features and constitution

Genetics

1

Biological maps that tell us who we are, where we came from, and how we are related to other creatures

Genes

2

Gene responsible for the gift of gab/language

FOXP2 at chromosome 2

3

Full set of chromosomes in a person's cells

Karyotype

4

31 billion base pairs; 22,000-25,000 genes; 1M book pages or 23 sets of encyclopedia brittanica

Human genome

5

90% of genes

Junk DNA

6

2% coding for proteins

Life functions

7

General study of all the many different genes that determine drug behavior

Pharmacogenomics

8

Factors for disease status

Genetic risk factors, genetic protective factors, environmental risk factors, environmental protective factors

9

View that genes (genotypes) cause traits (phenotypes) and can no longer be altered

Genetic Determinism

10

Your genes dictate who you are

Genetic Determinism

11

Study of the chemical reactions and the factors that triggers the activation/deactivation of parts of the genome at strategic times and locations

Epigenetics

12

Believes that DNA is not your destiny

Epigenetics

13

Affected by factors such as development in utero, environmental, chemicals, drugs/pharmaceuticals, aging, diet

Epigenetic mechanisms

14

Nutriets like folic acid, B vitamins, and SAM-e

DNA Methylation (-CH3 tag)

15

Family history functions

1. Aid in reaching a correct diagnosis
2. Helps in accurate prognosis
3. Presymptotic diagnosis

16

First affected individual in a family who brings genetic disorder

Proband

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Indicidual presenting for genetic counseling (not necessarily affected)

Consultant

18

Graphic representation of a medical family history of disease using symbols

Pedigree

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Provides both critical medical data and biological relationship information at a glance

Pedigree

20

Purpose of family pedigree

Diagnosis, testing startegies, pattern of inheritance, at risk family members, calculates risks, determine reproductive options, distinguish genetic from other risk factors, management, rapport, educate, explore patient's understanding

21

Characteristics of mendelian genetics

Variable expressivity
Clinical or genetic heterogeneity
Sex-influenced or sex-limited gene expression
Assortive mating
Small paternity size
Info on unaffected relatives is as important
Non paternity

22

Tounge rolling, cleft chin, dimples, hitchhiker's thumb

Dominant trait

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Ear lobe attachment

Recessive trait

24

AA or Aa affected genotypes

Autosomal dominant

25

Autosomal dominant characteristics

1. 50% chance of being affected
2. Males and females affected equally
3. Male-to-'ale transmission occurs

26

Fibroblast growth factor 3 mutation, skeletal dwarfism, rhizomelic shortening of limbs, increased skin folds

Achindroplasia

27

Fibroblast growth factor 2, prominent eyes, big nose, craniocynotosis, some mentally handicapped

Crouzon Syndrome

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Hypoplasia, webbed feet, higher incidence of mental handicap

Apert Syndrome

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Fibrilin 1 gene, tall sature, cardiovascular, skeletal and eye diseases, dilation and dissection of aorta

Marfan Syndrome

30

Affected individuals may be carriers

Autosomal Recessive

31

aa affected genotypes

Autosomal recessive

32

Each offspring has 25% chance of being affected

Autosomal recessive

33

Characteristics of Autosomal Recessive

1. 25% chance of being affected
2. Consanguinity
3. Skips generations
4. Males and females equally

34

One parent carrier autosomal recessive chances

50% chance not affected, carrier
50% chance not affected, not carrier

35

One parent affected autosomal recessive

100% carriers

36

Both parents carriers autosomal recessive

25% chance affected
50% chance carrier

37

One parent carrier/one affected autosomal recessive

50% chance affected
50% chance carrier

38

Keratin gene mutation, ichthyosis, increase in turnover of skin, fish like scales

Harlequin baby, autosomal recessive

39

Enzyme deficiency, normal at birth, onset at 2-3 years, loss of milestone skills, coarsening of facial features, build up of mucuopolysaccharides

Mucopolysaccharidosis Type 1 Hurler

40

Maple-syrup smell of urine, causes encephalopathy, cannot breakdown branched amino acids (V, I, L), accumulation of toxic metabolites, rare disease (tested in newborn screening

Maple Syrup Urine Disease, autosomal recessive

41

Cannot break down galactose, early onset of cataract, liver failure

Galactosemia, autosomal recessive

42

Mutation on the X chromosome, normal at birth but develops weakness of proximal muscles, trips easily, exaggerated lumbarlordosis

Duchenne Musular Dystrophy, X-linked recessive

43

MPS replaces inside of bones, deposition occurs in brain leading to neurologic deterioration

Mucopolysaccharidosis (MPS) II Hunter, X-linked recessive

44

Hemolysis, 1 in 50 prevalence in Philippines but of milder phenotype

Glucose-6-Phosphate Dehydrogenase (G6PD)

45

Genes and environmental factors, Affected population will be only those that have reached threshold

Multifactorial inheritance

46

Factors affecting multifactorial inheritance

1. Closer relationship to proband
2. High heritability of disorder
3. Proband of more rarely affected sex
4. Severe or early onset of disease in proband
5. Multiple affected members

47

Male or female child of affected mother has 50% chance of inheriting mutation, and thus affected

X-linked dominant

48

With affected father, all female children are affected and no male children will be affected

X-linked dominant

49

Normal birth, progressive neurodegeneration, loss of purposefuk use of hands

Rett Syndrome, X-linked dominant

50

Washer woman

Rett Syndrome, X-linked dominant

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Dosage of folic acid a month prior fertilization

400 microgram per day

52

Earliest time for a pregnancy test

6-8 weeks

53

How long is DNA in the mitochondria

16 kilobases

54

Maternal inheritance with symptoms like stroke, epilepsy, seizures, hearing loss, peripheral neuropathy

Mitochondrial inheritance

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3 characteristics of mitochondrial inheritance

1. Relatively well-known disease
2. Features that set it apart
3. Involves 3 or more organ systems

56

Genetic disorder with a repeat of 3 nucleotides

Triplet Expansion Disorders

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Infected mother gives disease to all her children

Maternal inheritance pattern

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Mixture of mutated and nonmutated mitochondria

Heteroplasmy

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Either all mutated or all nonmutated mitochondria

Homoplasmy

60

Organ systems usually affected are those that require a lot of ________

ATP

61

Poor generalized tone, mutation on DPMK gene due to repeats

Myotonic Dystrophy

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Patient with slow removal of hand after a handshake

Myotonic Dystrophy

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Repeat of CTG disorder

Myotonic Dystrophy

64

Distinct large ears, normal at birth but delay in speech (1st symptom) caused by constriction in one arm of the X chromosome

Fragile X chromosome

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Disorder with CGG repeat

Fragile X chromosome

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Huntington Disease

Triplet Expansion Disorder

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Only 1 copy of gene is expressed

Genomic Imprinting

68

Chromosome 15, father

Prader-willi syndrome

69

Fat (Michelin baby)

Prader, Willi syndrome

70

Nonverbal, happy puppet syndrome, prone to seizures, picket fence teeth

Angelman syndrome

71

Chromosome 15, mother

Angelman syndrome