Genetic Abnormalities Flashcards
What are the four types of genetic abnormalities?
1) monogenic
2) mitochondrial
3) complex trait/multifactoral
3) chromosomal
What happens in a genetic abnormality?
A single gene is affected.
What are three types of monogenic abnormalities?
1) autosomal dominant (only need one affected allele to have the disease)
2) autosomal recessive (need two affected alleles to have the disease)
3) x-linked recessive trait (in a woman with an affected allele, the other normal one makes up for it, but in a man, there isn’t a second, normal x chromosome to make up for the defective one
How are mitochondrial genes inherited and why?
- maternally
- because sperm only have mitochondria in the tail, which falls off when it reaches the egg)
How do mitochondrial gene abnormalities usually manifest?
- usually manifest as neuromuscular defects (since these areas use high amounts of energy)
Explain what a complex trait/multifactoral genetic abnormality is.
- polygenic (more than one gene)
AND - environmental factor
What two types of problems can occur when there is a chromosomal abnormality? Explain each.
1) problem with chromosome number
- extra chromosome in pair (trisomy) OR
- missing chromosome in pair (monosomy)
2) problem with chromosome structure
What is Klinefelter’s syndrome?
- trisomy, an extra X chromosome in a male (XXY)
- tall stature, lack of facial hair, wide hips, testicular atrophy and infertility, enlarged breasts
What is Turner’s syndrome?
- monosomy, a missing X chromosome in a female
- small stature, webbed neck, poor breast development, broad chest, amenorrhea, infertility, estrogen and progesterone deficiencies
What are the different types of problems with chromosome structure that can occur?
1) inversion (order changed/inverted in a chromosome)
2) translocation (portion is swapped in a pair)
3) deletion (portion deleted)
