Principles of Genetic Inheritance

Question 1

Chromatid

Answer 1

two=chromosome

Question 2

describe mosaicism

Answer 2

cells from a pt have different genotypes

-Down, Klinefelter, Turner syndromes

Question 3

Lyonization?

Answer 3

X-inactivation

Question 4

define non-disjunction

Answer 4

failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during division

Question 5

define acrocentric

Answer 5

centromere is near one end of chromosome

Question 6

Describe Robertsonian translocation

Answer 6

rare form of chromosomal rearrangement that, in humans, generally occurs in the five acrocentric chromosome pairs, namely 13, 14, 15, 21 and 22

Question 7

Describe genomic imprinting

Answer 7

methylation=down regulation

Question 8

describe uniparental disomy

Answer 8

a person receives two copies of a chromosome, or of part of a chromosome, from one parent and no copy from the other parent.[1] UPD can be the result of heterodisomy, in which a pair of non-identical chromosomes are inherited from one parent (an earlier stage meiosis I error) or isodisomy, in which a single chromosome from one parent is duplicated

Question 9

Describe lyonization

Answer 9

x is inactivated in individuals with two x chromosomes;

inactivation is random from cell to cell often

Question 10

define proband

Answer 10

the first diagnosed individual in a pedigree

Question 11

define penetrance

Answer 11

how frequently a gene manifests itself

Question 12

What does the independence principle dictate:

Answer 12

if two probabilities are independent then you can use the multiplication and addition rule

Question 13

What is disease prevalence data?

Answer 13

how many carriers in a population

Question 14

Define consaguineous

Answer 14

cousin matings are mare likely to produce rare autosomal recessive disorders (everyone likely carrier of 1-5 recessive mutations)