Medical Genetics Flashcards
Aneuploidy
A missing or extra chromosome. (Diagnosed via CMA or Karyotype)
Copy Number Variant
Gain or loss of several genes. AKA chromosomal deletions/duplications. (Diagnosed on CMA)
Point Mutation
A genetic variant (single gene mutation) that causes disease (pathogenic)
Benign Polymorphism
A genetic variant that does not cause disease (not pathogenic)
Single Nucleotide Polymorphisms (SNPs)
Variations from the reference genome at a single nucleotide. May occur in coding or non-coding regions. May or may not be pathogenic (usually isn’t).
Whole Genome Sequencing
Sequences the ENTIRE genome, including non-coding region. Detects Mendelian disease-causing variants.
Whole Exome Sequencing
Sequences only the coding region of the genome (1%). Can detect most point mutations.
Genome-Wide Association Studies (GWAS)
Research test used to “tease out” contribution of small genetic factors in multifactorial disease. Looks at SNPs across the whole genome. NOT used for polygenetic disease
Multifactorial Disease vs Polygenetic Disease
Multiple SNPs AND the environment cause disease vs ONLY multiple SNPs cause disease
Can Multifactorial or Polygenetic diseases be detected with genetic testing?
NO
What do Karyotypes/Complete Microarrays (CMAs) test for?
Chromosomal disorders/ Aneuploidy
What does DNA sequencing (with del/dup analysis) test for?
SNPs
What does a Next Generation DNA Sequencing Panel test for?
A phenotype caused by many genes (ie. Cardiomyopathy is caused by 80+ genes)
What does Whole Exome Sequencing test for?
Used to test phenotypes thought to be Mendelian, but no suspected singe gene OR for a limited differential of genes.
Epigenetics
The study of how genes are EXPRESSED.
