Genetic Screening

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;