Genetic Variation

Flashcards related to mutations, chromosomal rearrangements, genetic variations, and neurological disorders discussed in the lecture.

Non-disjunction

Failure of homologous chromosomes and sister chromatids to separate.

Robertsonian

Translocation and causes inheritable downs, issues with segregation at meiosis

MECP2

regulation of gene expression and nerve cells

duplication in girls can cause delayed development and seizures

Methylation

Adding a methyl group to a molecule and can alter gene expression. Vital for environmental and regulation inheritable changes.

Slippage mispairing mechanism

Replicating strand slips by one repeat length; new strand extra repeat causing earlier onset.

Huntingtons

Progressive degeneration of neurons, typically onset at 35-45, death within 20 years, autosomal dominant, CAG repeat in exon 1 in HTT gene; more than 40 repeats.

Trofinetide

Inhibits overactivation of inflammatory microglia and astrocytes to promote synapse connections; used for MECP2 mutations.

SNPs

Single nucleotide polymorphisms.

INDEL

Unsure if insertion or deletion.

Synonymous mutations

Mutations that cause no change in amino acid sequence.

Nonsynonymous mutations

Mutations that alter amino acid sequence.

Missense mutations

Converts amino acid to stop codon.

Acrocentric chromosome

Where the centromere is located near one end.

Rett Syndrome

X-linked neurological disorder mainly affecting girls, causing intellectual disability; associated with MECP2 mutations coding for MeCP2 which binds to methylated CGGs for transcription.

Chromosomal Rearrangement

Direct disruption, gene copy number variation.

Induced Mutation

UV leading to pyrimidine dimers and deletions in replication

Copy Number Variations

longer than 100 base pairs and encompass whole genes