Biotechnology Lesson Number 1 What is Genetic Counseling

Biotechnology Lesson Number 1

What is Genetic Counseling? • A service for couples with a risk of having a child with a certain disease • The counselor will: • Take a family history. • Construct a pedigree. • Determine type of inheritance. • Suggest and arrange for testing. • Provide support.

Types of Prenatal tests • Karyotype – shows abnormalities in chromosomes • Cells in metaphase – • used to see visible chromosomes • chromosomes are arranged in ordered pairs • Shows extra or missing chromosomes

Types of Prenatal tests • Sampling of embryonic material • Amniocentesis (fluid surrounding the fetus) • Done at 14 -18 weeks • Chorionic villus sampling (outer tissue) • Can be performed at 8 weeks

Types of Prenatal tests • Maternal serum screening – test of blood for levels of certain substances or DNA analysis • Ultrasound (visual image) • Family exome analysis • order of DNA bases • uses DNA that codes for proteins • searches for mutations in family members

Biotechnology and Genetic Testing • Use of biotechnology tools to analyze DNA • Diagnostic tools: • DNA fingerprinting • shows unique individual patterns in DNA • also used for crime scene detection • PCR (polymerase chain reaction) • produces large amounts of DNA from a small sample • Restriction Enzymes “DNA scissors” • cuts DNA strands in the same location to create DNA fragments

Biotechnology and Genetic Testing • DNA fingerprinting and Gel Electrophoresis • DNA samples are cut with the same restriction enzymes to create DNA fragments • Gel electrophoresis is used to separate DNA fragments by size to show fragment length. • Electrical current pulls DNA fragments through the gel • Each sample is loaded into the gel for comparison to known DNA.

Biotechnology and Genetic Testing • Treatment options: • Gene therapy • using an inactive virus to replace a defective gene • Gene cloning • produces large amounts of compounds for treatment (ex. , cloned insulin for diabetes patients) • Pharmacogenetics • determining drug treatment choice and dosage based in individual DNA