Molecular Identification of Inherited Diseases

Question 1

Genomic Imprinting

Answer 1

Enzymatic addition of methyl groups to specific nitrogen bases in a predicted pattern throughout the genome.

Question 2

Congenital

Answer 2

Born with, referring to diseases with genetic components.

Question 3

Lyon Hypothesis

Answer 3

Only one X chromosome remains genetically active in females. The other X chromosome is inactivated about the 16th day after embryonic development.

Question 4

Barr Body

Answer 4

A structure visible in the interphase nucleus formed by the inactive X chromosome in female mammals.

Question 5

Polyploidy

Answer 5

In diploid organisms, more than two of any autosome.

Question 6

Nondisjunction

Answer 6

Abnormal separation of chromosomes during cell division resulting in both of a chromosome pair in one daughter cell.

Question 7

Triploid

Answer 7

Having three of each chromosome.

Question 8

Marker Chromosomes

Answer 8

An unknown chromosome or part of a chromosome of unknown origins.

Question 9

Transmission Patterns

Answer 9

Mode of inheritance of a phenotype within a family.

Question 10

Autosomal-dominant Transmission

Answer 10

A child of an infected individual and an unaffected male has a 50% to 100% risk or likelihood of expressing the disease phenotype.

Question 11

X-linked

Answer 11

Sex-linked recessive. Having genetic components located on the X-chromosome.

Question 12

3 main mendelian transmission patterns

Answer 12

Autosomal dominant, autosomal recessive, and X-linked.

Question 13

Autosomal-dominant Transmission

Answer 13

An inheritance pattern where a child of an infected individual and an unaffected individual has a 50% to 100% risk or likelihood of expressing the disease phenotype.

Question 14

Gain-of-function Mutation

Answer 14

The new properties of the mutant allele are responsible for the phenotype even in the presence of the normal allele. A phenotype having a new undesired trait.

Question 15

Loss-of-function Mutation

Answer 15

A phenotype that is usually recessive, but it depends on the type of the protein affected.

Question 16

Loss-of-function Mutation

Answer 16

A phenotype that is usually recessive, but it depends on the type of the protein affected.

Question 17

Loss-of-function Mutation

Answer 17

A phenotype that is usually recessive, lacking a desired trait, but it depends on the type of the protein affected. In diploid organisms, inactivation of the normal allele is responsible for the phenotype.

Question 18

Autosomal Recessive

Answer 18

Largest category of mendalian disorders. Recurrence risk is 25% if a sibling is affected, 50% for the child of an affected and unaffected individual, 100% for the child of two affected individuals.

Question 19

Gonadal Mosaicism

Answer 19

The presence of more than one genotype in the germ cells of an individual.

Question 20

New Mutations

Answer 20

A spontaneous mutation arising in germ cells of an unaffected individual.

Question 21

Sex-linked Disorders

Answer 21

Having genetic components located on the X or Y chromosome.

Question 22

Hemizygous

Answer 22

The presence of only one of two possible alleles in a diploid genotype.

Question 23

Penetrance

Answer 23

The frequency of expression of disease phenotype in individuals with a gene lesion.

Question 24

Cytochrome P-450

Answer 24

A group of enzymes localized to the endoplasmic reticulum.

Question 25

Cytochrome P-450

Answer 25

A group of enzymes localized to the endoplasmic reticulum.

Question 26

Autophagy

Answer 26

Degradation of intracellular substrates within the cell.

Question 27

Heterophagy

Answer 27

Intercellular degradation of extracellular substrates taken into the cell by phagocytosis or endocytosis.

Question 28

Cytochrome P-450

Answer 28

A group of enzymes localized to the endoplasmic reticulum that participates in enzymatic hydroxylation reactions and also transfers electrons to oxygen.

Question 29

Gonadal Mosaicism

Answer 29

The presence of more than one genotype in the germ cells of an individual.

Question 30

Premutations

Answer 30

A genetic lesion not manifesting a disease phenotype but prone to advance to full mutation/disease status.

Question 31

Uniparental Disomy

Answer 31

Inheritance of chromosomal material from only one parent due to aberrant separation of chromosomes during meiosis.