Flashcards in Congenital Abnormalities Deck (25):
When is the period of vulnerability?
2-15 weeks post-conception during organogenesis
What are teratogens?
Any factor present in the environment of the embryo or mother causing birth defect
What mono genie abnormalities are there?
Autosomal dominant, autosomal recessive, and X-linked recessive
What is an autosomal dominant genetic abnormality?
There is a 50% chance of inheriting the defective gene, one parent has the defective gene
What is an autosomal recessive genetic abnormality?
Two defective genes must be present in order for the defect to be expressed, 50% carrier, 25% unaffected, and 25% affected
What is a X-linked recessive genetic abnormality?
Males are always affected because this defect occurs on the X chromosome. Females have another X to make up for the defective X whereas males have a Y which does not make up for the defective X
Which parent is a mitochondria gene disorder inherited from and why?
The mother because maternal gametes contain more mitochondria than paternal gametes as most of the mitochondria is lost in the tail of the sperm when it falls off
What type of defects are often seen in mitochondria gene disorders and why?
Neuromuscular defects because mitochondria genes code for proteins that make up systems in the body that create ATP and without those systems there is not enough ATP for muscles
What is a complex trait genetic abnormality?
It is a polygenic defect that involves a gene coupled with the environment
What types of chromosomal abnormalities are there?
Numerical and structural abnormalities
What is a numerical chromosomal abnormality?
Aneuploidy, too many or too little chromosomes in a pair
What is trisomy?
An extra chromosome in a pair, making there three chromosomes
What is monosomy?
A chromosome missing from a pair
What is Down's syndrome called?
Describe Kleinfelter's Syndrome
Trisomy on the sex chromosomes that affects males. Males have an extra X chromosome (XXY)
What are clinical manifestations of Kleinfelter's syndrome?
Enlarged breasts, small testes, infertility, long limbs, and lack of facial and body hair
Describe Turner's syndrome
Affects females. Female is missing one X chromosome (XO)
What are clinical manifestations of Turner's syndrome?
Poor breast development, webbed neck, small stature, infertility, and broad chest
What are three structural deficits of chromosomal abnormalities?
Inversion, translocation, and deletion
What is deletion?
Deleting part of a chromosome and losing genetic material
What is translocation?
Exchange of segments of chromosomes
What types of inversion are there?
Pericentric and paracentric
What is pericentric inversion?
Two breaks in a chromosome that invert around the centromere
What is paracentric inversion?
Two breaks in a chromosome with the fragment inverting but remaining on same arm, not around centromere