a) Polymerase Chain Reaction (PCR)
Polymerase Chain Reaction (PCR) is a laboratory technique used to make multiple copies of a specific segment of DNA. It was developed by Kary Mullis in 1983 and revolutionized genetic research.
Steps in PCR:
- Denaturation: DNA is heated to separate the strands.
- Annealing: Short primers bind to specific sequences.
- Extension: DNA polymerase synthesizes new DNA strands.
These steps are repeated for 25–35 cycles to produce millions of DNA copies.
Applications:
- DNA fingerprinting
- Genetic disease diagnosis
- Forensic science
- COVID-19 testing
b) HapMap Project
The HapMap (Haplotype Map) Project was an international research effort to identify and catalog genetic similarities and differences in human beings. It focused on understanding common patterns of human genetic variation, especially single nucleotide polymorphisms (SNPs).
Goals:
- To aid in finding genes linked to diseases
- To develop better drugs and treatments
The project began in 2002 and involved populations from Africa, Asia, and Europe. It paved the way for genome-wide association studies (GWAS).
c) Ethical Principles in Genetic Research
Genetic research raises many ethical concerns, particularly around privacy, consent, and potential misuse of information.
Key Ethical Principles:
- Informed Consent: Participants must be informed and agree voluntarily.
- Privacy and Confidentiality: Genetic data must be protected.
- Non-discrimination: Genetic information should not be used to discriminate in jobs, insurance, etc.
- Right to Know and Not to Know: Participants may choose whether or not to receive results.
Ethics committees and laws such as GINA (Genetic Information Nondiscrimination Act) play a role in enforcing these principles.
d) Phenylketonuria (PKU)
Phenylketonuria (PKU) is a genetic disorder caused by a mutation in the gene that produces the enzyme phenylalanine hydroxylase. This enzyme is needed to break down the amino acid phenylalanine.
Symptoms:
- Intellectual disability
- Seizures
- Behavioral problems
Treatment:
- Early diagnosis through newborn screening
- Special diet low in phenylalanine
If untreated, PKU can lead to severe mental retardation, but early detection and management can prevent complications.