Molecular and Cell Genetics: Genetics Basis of Disease

Genetic Basis of Disease

• Genetic variation can lead to disease, as seen in Cystic Fibrosis (CF), Huntington's Disease (HD), and psoriasis
• Epigenetic changes can also lead to disease, such as in Fragile X syndrome

Genetic Variation and Genetic Disease

• Genetic variation refers to changes in the nucleotide sequence of DNA
• Types of genetic variation include:
  • SNV (Single Nucleotide Variant): a difference in a single nucleotide
  • CNV (Copy Number Variant): insertion, deletion, inversion, or duplication of >1,000 nucleotides
  • Chromosomal Variation: variation in chromosome number, multiple sets of chromosomes
  • STRs (Short Tandem Repeats): repetitive elements comprised of recurring DNA motifs of 2-6 bases

Epigenetic Changes and Epigenetic Disease

• Epigenetic changes refer to chemical modifications to DNA or histone proteins without altering the underlying DNA sequence
• Fragile X syndrome is an example of a disease caused by epigenetic changes

Functional Genomics and High-Throughput Technologies

• Functional genomics involves the study of the function of genes and their products
• High-throughput technologies enable the rapid analysis of large amounts of genomic data
• Population-based initiatives for stratified medicine aim to identify genetic variations associated with specific diseases and develop targeted treatments

Key Terms

• Genome: an organism's complete set of DNA
• Gene: a distinct sequence of nucleotides representing the unit of genetic information
• Allele: each of two or more alternative forms of a gene that arise by variation
• Genetic variant: a change in the nucleotide sequence of the DNA

This quiz covers the genetics basis of disease, including how genetic and epigenetic changes can lead to disease and the role of genomics and functional genomics in 21st century medicine.