disorders of development

Question 1

define genetic disease

Answer 1

a disease that occurs primarily from a genetic abnormality

Question 2

define inherited

Answer 2

caused by an inherited genetic abnormality

Question 3

define single gene disorder

Answer 3

abnormality of a single gene causes a disease

Question 4

2 types of single gene disorder

Answer 4

dominant
recessive

Question 5

describe dominant disorders

Answer 5

Dominant single gene disorders will produce the disease where there is only one copy of the abnormal gene

Question 6

describe recessive disorders

Answer 6

Recessive single gene disorders will only be expressed if both copies of the gene are abnormal.

Question 7

how are single gene disorders further classified

Answer 7

autosomal or sex linked

Question 8

example of single gene disorder

Answer 8

sickle cell anaemia, which is caused by a point mutation in the beta-globin chain of haemoglobin which always produces an abnormal haemoglobin which causes red blood cells to deform when oxygen saturation is low.

Question 9

define Polygenic gene disorder:

Answer 9

a genetic disease which is the result of the interaction of several different genes (usually on different chromosomes)

Question 10

example of polygenic disorder

Answer 10

breast cancer
The genes BRCA1 and BRCA2 have a large individual effect on breast cancer.
Most of breast cancer risk is composed of incremental rises in risks by tens to hundreds of apparently unrelated genes even when there is a strong family history.

Question 11

define congenital disease

Answer 11

a disease someone is born with

Question 12

how are congenital disease also acquried

Answer 12

often by a disease which is due to environmental factors but it may have a strong genetic background.

Question 13

define acquired disorder

Answer 13

caused by non genetic enviornmental factorrs