Genetic Counseling and Testing Overview

Genetic Counseling

• Genetic tests diagnose/determine if a person has a genetic disorder or is a carrier.
• This helps genetic counselors provide information about an unborn child's potential genetic conditions.

Amniocentesis

• Ultrasound guides a needle into the amniotic sac to retrieve fluid.
• The fluid contains fetal cells.
• Determines specific genetic disorders in the baby (e.g., chromosomal abnormalities, neural tube defects).
• Used to get DNA for paternity testing.

Chorionic Villi Sampling

• Chorionic villi cells are removed from the placenta.
• Transcervical (through the cervix) or transabdominal methods are used.
• Ultrasound guidance is used to extract a tissue sample from the placenta.
• Used to identify inherited genetic diseases and disorders.

Newborn Screening

• Detects genetic or metabolic conditions early.
• Early diagnosis for treatment is crucial.
• Uses neonate's blood.
• Identifies affected newborns quickly.
• Provides prompt treatment and care.

Carrier Screening

• Determines if individuals carry a gene for a recessive disease.
• Even if the individual doesn't show the trait phenotypically, knowing they have it helps families plan.

Karyotypes

• Picture of chromosomes organized by size and shape.
• Can help identify missing or abnormal chromosomes or multiple copies.
• Aids in diagnosing chromosomal disorders.

Ultrasonography

• Uses high-frequency sound waves.
• Produces real-time images showing fetal development and movement.
• Used to identify physical disorders (e.g., dwarfism, spina bifida, underdeveloped limbs).

Polymerase Chain Reaction (PCR)

• Denaturation: DNA strands separate at high temperature.
• Annealing: Primers attach to the target DNA sequence.
• Extension: DNA polymerase replicates the target DNA.