Genetic's #2 Flashcards
(12 cards)
What are X-linked recessive conditions?
- Sex-linked disorder in which an unaffected mother carries 1 normal and 1 mutant allele on X chromosome.
- Affects more males than females (males only have 1 X chromosome)
What caused red green colour blindness?
-Loss of red or green photopigments located in cone-shaped cells within retina
What are atypical single- gene disorders?
- Don’t follow mendelian pattern of inheritance
- triplet repeat mutations
- mutations in mitochondrial genes
What are triplet repeat mutations?
- Characterised by a long repeating sequence of 3 nucleotides in a gene that disrupts function
eg. Huntington’s disease
Mutations in mitochondrial genes?
Can affect tissues and organs that are highly dependent on oxidative phosphorylation
What are some diseases caused by mutations in mitochondrial genes?
- Liver dysfunction
- Bone marrow failure
- Diabetes
Chromosomal abnormalities- Alteration in structure
- Deletion
- Duplication
- Inversion
- Ring
- Translocation
Chromosomal abnormalities- Alteration in number
- Monosomy
- Trisomy
- Tetrasomy
- Triploidy
What is deletion?
Simple loss of a chromosomal segment
What is duplication?
The presence of two copies of a chromosomal region
What is inversion?
A segment of a chromosome breaks of and then reattached in a reversed direction
What is a ring chromosome?
Breakage and two ends joining to form ring
