genetic influence on patient outcomes, note taking guide

Question 1

aneuploidy

Answer 1

not having 23 chromosomes in each cell

Question 2

trisomy

Answer 2

3 copies of one chromosome instead of two copies

Question 3

monosomy

Answer 3

1 copy of one chromosome, missing one chromosome from a pair, results in 45 total instead of 46

Question 4

loss of chromosomal material

Answer 4

is worse than duplication, as it results in less genetic material available for use

Question 5

list the four abnormalities of structure of DNA

Answer 5

deletion
duplication
translocation
inversion

Question 6

deletion

Answer 6

loss of parts of chromosomes, may cause significant congenital anomalies, intellectual and physical disability. Produces worst effects.

Question 7

duplication

Answer 7

type of mutation that involves the production of one or more copies of a gene or region of a chromosome

Question 8

inversion

Answer 8

when a segment breaks off and reattaches within the same chromosome, but in reverse orientation

Question 9

translocation

Answer 9

when one chromosome breaks or loses a piece, and the fragmented pieces attach to different chromosomes or attach to each other in different places

Question 10

genes

Answer 10

sequences of DNA, in nucleus

Question 11

where does protein synthesis take place?

Answer 11

cytoplasm

Question 12

list the 4 DNA bases

Answer 12

adenine A, cytosine C, guanine G, thymine T

Question 13

How is new DNA formed?

Answer 13

Thru replication, when enzymes break the hydrogen bonds between bases, (unzipping the helix) leaving each single strand unpaired. Then the single strands pair with new peptides thru complementary base pairing, A with T and G with C. The unpaired base will only pair with the proper protein.

Question 14

What is the template guide when new DNA is formed?

Answer 14

the single strand of DNA that remains after unwinding

Question 15

list the most common genetic abnormalities

Answer 15

trisomy, monosomy, mosaicism

Question 16

missense mutation

Answer 16

change in a single amino acid in a protein

Question 17

nonsense mutation

Answer 17

when mutation introduces a premature stop codon

Question 18

pedigree charts

Answer 18

help analyze modes of inheritance, a diagram that shows how trait or disease is passed down thru a family

Question 19

sex linked recessive genetic disease

Answer 19

mutations/genetic conditions on the X chromosome, affects males more frequently than females, because males have only 1 X and 1 Y - if affected gene has the illness, it will be expressed

Question 20

recessive

Answer 20

When individual inherits of a mutated gene, one from each parent, when unaffected parents have affected offspring. If males are more affected, it is sex-linked

Question 21

gender determination

Answer 21

Combination of sex chromosomes, XX or XY. The Y chromosome carries the SRY (sex-determining region Y) gene, which triggers the development of male sex organs (testes). Begins in 6th week of gestation. In the absence of the SRY gene, the embryo develops female sex organs (ovaries). If there is an XY without the SRY, person will have female characteristics.

Question 22

what causes neural tube defects?

Answer 22

genetic, environmental, nutritional (lack of maternal folic acid)

Question 23

monozygotic

Answer 23

MZ, separate but identical embryos, natural clones, twins

Question 24

dizygotic

Answer 24

DZ, fraternal twins, double ovulation with different sperm fertilizing each egg, can be different fathers, are like regular siblings and only share half their DNA

Question 25

relative risk

Answer 25

rate of probability, not actual occurrence of disease

Question 26

imprinting

Answer 26

only one copy of a gene in an individual (either from mother or father) is expressed, while other copy is suppressed or silenced. Unlike genomic mutations that can affect the ability of inherited genes to be expressed, genomic imprinting does not affect the DNA sequence itself. Instead, gene expression is silenced by the epigenetic addition of chemical tags to the DNA during egg or sperm formation. Epigenetic tags on imprinted genes usually stay in place for the life of the individual

Question 27

Examples of imprinting

Answer 27

Prader-Willi, Angelman Syndrome, Beckwith-Wiedemann, Russell-Silver Syndrome, where expression of genes depends on parental origin

Question 28

probability

Answer 28

mathematical measure of likelihood. Calculates likelihood of specific traits being inherited by offspring from parents.

Question 29

punnett square

Answer 29

diagrams that help determine the likelihood of an offspring inheriting specific traits based on the parents' genotypes.

Question 30

how many chromosomes are same in males and females

Answer 30

22. 23rd is the sex chromosome. Most people have 46 chromosomes, in 23 pairs.

Question 31

Down Syndrome

Answer 31

trisomy 21. Extra copy on chromosome 21. Small stature, almond shaped eyes, flattened facial features, small ears, short neck, weak muscle tone, intellectual disability, vision/hearing problems, thyroid disease, cancer, increased risk for Alzheimer's (because chromosome 21 produces amyloid plaques, so there is an extra chromosome producing plaques)

Question 32

Turner Syndrome

Answer 32

45X0. Deletion of sex chromosome, 46-1= 45. When females only have 1 X chromosome. Sometimes they also have a partial Y chromosome, without the SRY portion. No period, missing or undeveloped ovaries, infertile, must adopt to have kids. No pubic hair, wide nipples, renal hypoplasia, horseshoe kidney, short stature, small mandible, high palate, low set ears, low hairline, webbed neck, 50% chance of congenital heart defects, bicuspid aortic valve, coarctation of aorta, lymphedema of hands and feet. Tx is HGH, estrogen

Question 33

Klinefelter Syndrome

Answer 33

47 XXY, or 48 XXXY, or 49 XXXY. Male has extra X chromosome. Most common cause of primary hypogonadism, azospermia, and infertility in males. Infertile, poorly formed testicles, micro-penis, gynecomastia, tall, normal pubic and axillary hair, intellectual disability, infertility, behavioral problems, low testosterone, high FSH/LH, high risk of pulmonary disease, varicose veins, ADHD, high chance of breast and testicular cancer, high risk of high cholesterol and atherosclerosis. Tx testosterone and androgen therapy

Question 34

Cri du Chat

Answer 34

Cry of the cat, due to high pitched cry that sounds like a cat's meow characteristic of these babies. Not inherited. Deletion in chromosome 5, on the P arm of the chromosome. "Floppy baby." Weak muscle tone, so will need therapy for swallowing, sucking. Ventricular septal defect, microcephaly, round face, wide eyes, hypotonia, intellectual disability, low ears, small jaw, heart defects, speech delay.

Question 35

When to test genetics

Answer 35

When family hx indicates it. May need to refer to genetic counselor. Women over age 35, old egg theory.

Question 36

Single gene testing

Answer 36

to diagnose disease

Question 37

Panel testing

Answer 37

looking for mutations, CA

Question 38

genomic testing

Answer 38

entire genetic makeup, markers predict disease progression, how genes and environment interact are predictors of health

Question 39

non-invasive prenatal testing

Answer 39

screening for disease in women over 35, men over 35. Blood draw from mother, also predicts twins Ex panorama - screens for conditions like Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13), and sex chromosome abnormalities (monosomy X, triploidy).

Question 40

amniocentesis

Answer 40

sampling amniotic fluid by inserting needle into uterus, guided by ultrasound, usually between 15-20 weeks. To test for genetic or chromosomal abnormalities. Small risk of miscarriage that can be minimized if experienced pros perform procedure.

Question 41

transcription

Answer 41

1st process information passed from one structure to another prerequisite for translation unzipping of DNA

Question 42

translation

Answer 42

2nd and last step of gene expression mRNA interacts with tRNA to produce a protein