Genetic Disease Flashcards Preview

Pathophysiology > Genetic Disease > Flashcards

Flashcards in Genetic Disease Deck (31):
1

What is a congenital disease?

Disorders present at birth (3% of all newborns)

2

Genotype

-the genetic constitution of an individual organism

3

Phenotype

-the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment

4

Which gene is responsible for eye color?

-chromosome 15: OCA2 gene determines the production and storage of melanin (protein)
-less melanin = blue eye color;
-more melanin = brown eye color

5

How many autosomes do humans have?

-22 autosomes
-1 pair of sex chromosomes

6

how are chromatids fused?

by centromeres

7

Haploid

Set of chromosomes divided in half (diploid (2n) to haploid (n))

8

Haploid

Set of chromosomes divided in half (diploid (2n) to haploid (n))

9

What is the process when homologous chromosomes undergo genetic recombination?

crossing over

10

What happens in interphase?

DNA replication

11

What happens in Meiosis I?

homologous separate (2n becomes 1 n)
-crossing over

12

What happens in Meiosis II

-Sister chromatids separate

13

Euploidy

When there is more than 1 chromosome set that has more or less than an extra chromosome

14

Aneuploidy

If there is only 1 chromosome extra or less

15

Chromosomal mutations

-alteration in number or structure of chromosomes
-affects many genes
-problems during meiosis

16

Chromosomal mutations

-alteration in number or structure of chromosomes
-affects many genes
-problems during meiosis

17

Why is XXX or XYY not show phenotype?

In every female, one of the X chromosomes is active and the other is inactive. So in XXX, two X's are inactive

In XYY just extra testosterone

18

Klinefelter syndrome

-less estrogen

19

Monosomy

XO (Turner syndrome)
-later in life 1 of the Xs is inhibited
-infertile (miosis inhibited because only 1 X)

20

Genetic mutations

-changes a single base pair of DNA or addition/deletion of one or more base pairs (occurs during replication)
-affects only one gene, abnormal structural, enzymatic or regulatory proteins
-example: sickly cell anemia

21

Recessive alleles

cause effect only when there is no other allele to mask it, usually codes for nonfunctional products

22

Dominant alleles

are phenotypically expressed whenever one allele is present; usually codes for an active protein with altered function

23

chromosomal mutation

-# or structure (many genes)
-severe or mild
-meiosis

24

genetic mutation

-point mutations
-one gene (recessive or dominant phenotype)
-happens during replication of DNA
-Change is single base pair of DNA or addition/deletion

25

What are the two types of genetic mutations?

1. recessive
2. dominant

26

What usually codes for nonfunctional products?

recessive alleles (cause effect only when there is no other allele to mask it)

27

What usually codes for active protein with altered function?

dominant alleles (phenotypically expressed whenever one allele is present)

28

What are pedigrees?

used to describe/trace the transmission of a disease
-help sort out etiology of genetic disease

29

Where do sex-linked traits arise from?

X-chromosome

30

What disorders are women twice as freqently expressed in woman

Dominant X-linked

31

What disorders are carried twice as frequently in woman but expressed far more often in men? (e.g. Duchene's muscular dystrophy, red-green color blindness)

Recessive X-linked