neurogenetics Flashcards
epigenetics
What is epigenetics?
epigenetics is the study of heritable changes in the phenotypes or gene expression caused by mechanisms other than changes in the underlying DNA sequence, hence the name epi (above) genetics
What are processes that mediate epigenetic modifications?
- developmental epigenetic change
- environmental cues
- epimutation
what are structural arrangements of nuclear DNA (epigenetics)?
- heterochromatin is tightly packed and transcriptionally inactive
- constitutative heterochromatin: centromere, telomere, Y chromosomes and others
- facultative heterochromatine
- Euchromatin: open DNA, accessible for transcription
What are the 3 types of epigenetic modifications?
- histone modification
- RNA interference
- DNA methylation
What is Karyotyping? What is the advantage?
Chat GPT: A high-resolution technique to detect small genetic changes (copy number variations) across the genome by analyzing DNA on a microarray chip.
Process:
DNA Collection & Labeling - DNA from the patient is extracted and labeled with a fluorescent dye.
Hybridization - Patient DNA is applied to a microarray chip containing DNA probes.
Scanning & Analysis - Fluorescence patterns show gains or losses of DNA segments.
Uses:
Identifies submicroscopic deletions/duplications (e.g., in autism, developmental delays).
Detects chromosomal changes in cancers.
Useful in prenatal testing for finer genetic details.
Advantages:
More detailed than standard karyotyping; can detect small variations and copy number changes.
Limitations:
Does not detect balanced rearrangements (e.g., inversions, translocations) or very small mutations.
What are the applications of microarrays?
- genomic disorders: copy number variation (CNVs)
- mapping mendelian disorders: linkage analyse
- mapping risk alleles in complex disorders: GWAS
- expression studies (transcriptomics)
