How genetic screening is carried out in an adult human
- samples of cells taken
- e.g white blood cells
- test for chromosomal abnormalities
- e.g Down’s Syndrome
- cells cultured so that they divide
- stopped at metaphase
- use of colchicines
- cells made to take up water
- chromosomes separated
- karyotype produced
- flourescent makers to help detect abnormalities
- test for particular allele
- DNA extracted
- DNA cut with restriction enzyme
- electrophoresis occurs
- to separate DNA into strands
- complementary/specific probe(for mutant allele)
The advantages of screening for genetic conditions
- information about the increased risk of person having genetic conditions ;
- ref. breast cancer/ named example ;
- allows people to prepare for late onset genetic conditions ;
- ref. Huntington’s disease/Alzheimer’s disease/named example ;
- identify whether fetuses are going to develop a genetic condition ;
- so can give early treatment when born ;
- allows parents to prepare for the birth of a child who will need treatment for a considerable time or even throughout life ;
- identifies carriers of genetic conditions ;
- helps to provide early diagnosis ;
- allows couples who are both carriers of a genetic condition to make decisions about starting a family/ having more children/ seeking IVF ;
The advantages and disadvantages of genetic screening in humans.
- Advantages
- known risk for next generation;
- allows possible abortion of affected fetus;
- allows sorting of IVF embryos;
- Disadvantages
- loss of hope;
- insurance company problems;
- employment problems;
- miscarriage risk;
- trauma of knowledge;