1M - Genetics Flashcards
study of genes, heredity, and the variation of the inherited characteristics
Genetics
deals with the etiology and pathogenesis of human diseases that are at least partially genetic in origin, along with their prediction and prevention
medical genetics
study of gene function and interaction
genomics
how many percent of individuals is diagnosed with a genetic defect by age 15?
3%
2-3% newborns
8-10% by age 18, have one or more functional or developmental characteristics
biochemical gene marker for breast cancer?
BRCA 1 and 2
Which project identified more than 25,000 human genes which led to a rapid expansion of genomic research to better understand disease biology
Human Genome Project 2003
Genetic code varies every 200-500 base pairs usually as?
SNP (single nucleotide polymorphism)
How many single nucleotide polymorphism does the human genome have?
more than 80
Aneuploidy accounts for how many percent of 2nd trimester miscarriages?
20%
> 50% of 1st trimester miscarriages
6-8% of stillbirths and early childhood deaths
Trisomy 21`
Down Syndrome - 50% of aneuploidy cases
Trisomy 18
Edward - 15% of aneuploidy cases
Trisomy 12
Patau - 5% of aneuploidy cases
p in chromosome nomenclature stands for?
Short arm
q in chromosome nomenclature stands for?
long arm
nomenclature for trisomy 21 in a genetic male
47, XY, +21
Nomenclature for Klinefelter syndrome
47, XXY
Nomenclature for Turner Syndrome
45, X or 45, XO
How many chromosomes are there in a euploid?
46
how many chromosomes are there in a aneuploid?
gain or loss from 46
a polyploid chromosome has?
a multiple of haploid 23 e.g. 69
half of all chromosomal abnormalities?
Autosomal trisomy
Trisomy most commonly results from?
Non disjunction
How does non disjunction happen?
Failure to pair up
pairs up but separates prematurely
fail to separate
risk for any autosomal trisomy is greatly increased after reaching what maternal age?
35