Genetic factors and disease

Question 1

What are the 3 main causes of disease

Answer 1

Genetic, multifactorial, environmental

Question 2

Overview of genetic diseases

Answer 2

E.g cystic fibrosis, Huntington’s
Individually rare
Cumulatively enough to have regional genetic services

Question 3

Overview of multifactorial diseases

Answer 3

E.f=g spina bifida, diabetes

Main cause of disease in developed countries

Question 4

Overview of environmental diseases

Answer 4

Poor diet
Infection
Druggs
Accidents
Main cause of disease in 3rd world countries

Question 5

Definition of phenotype

Answer 5

Appearance of an individual which results from the interaction of the environment and the genotype

Question 6

Definition of genotype

Answer 6

Genetic constitution of an individual

Question 7

What is an allele?

Answer 7

One of several forms of a gene at a specific locus

Question 8

What is polymorphism?

Answer 8

Frequent hereditary variations at a locus

Question 9

Define homozygous

Answer 9

Both alleles at the same locus

Question 10

Define heterozygous

Answer 10

Alleles at a locus are different

Question 11

Define hemizygous

Answer 11

Only one allele refers to a locus on an x chromosome in a male

Question 12

What are the 3 main ways you can classify genetic disease

Answer 12

1) Chromosomal
2) Mendelian
3) Non-traditional

Question 13

Examples of Mendelian classifiaction

Answer 13

Autosomal dominant
Autosomal recessive
X-Linked

Question 14

Examples of non-traditional classification

Answer 14

Mitochondrial
Imprinting
Moasaicism

Question 15

What is autosomal dominant inheritance

Answer 15

Disease which is manifest in the heterozygous state

Question 16

What does a pedigree of autosomal dominant inheritance look like?

Answer 16

Affected in every generation-both males and females

Question 17

What is autosomal recessive inheritance?

Answer 17

Disease which is manifest in the homozygous state

Question 18

What is x-linked recessive inheritance?

Answer 18

Caused by pathogenic variants in genes on the x-chromosome

Question 19

What is mitochondrial inheritance?

Answer 19

DNA inherited solely from mother-passed on to male s but males cant pass it on

Question 20

How can 2 unaffected parents produce an affected child if the disease is autosomal dominant

Answer 20

Non-paternity
New dominant variant
Gonadal mosaicism

Question 21

What is imprinting?

Answer 21

For some genes only 1 out of the 2 alleles is active depending on the genes it can be the paternal or maternal allele