← All decks
Dermatology
Basic Principles of Genetics
Built from Dermatology, 5th Edition
What’s inside
9 sections · 96 slides
Overview
- The human genome, in brief
- Why genetics matters to dermatologists
- Epigenetics: change without changing the code
- Three types of genetic disease
- Genetics vocabulary you will need
- Basic concepts in genetics
- Basic concepts in genetics (continued)
- Basic concepts in genetics (continued)
- Basic concepts in genetics (continued)
- Basic concepts in genetics (continued)
- Two kinds of DNA variation
Mendelian inheritance patterns
How single-gene diseases pass from parent to child
- Building a pedigree
- Dominant vs recessive alleles
- Same gene, different disease: allelic heterogeneity
- Examples of allelic heterogeneity in genodermatoses 2 – 11
- Same disease, different gene: locus heterogeneity
- Examples of genodermatoses with locus (genetic) heterogeneity 12 – 18
- Autosomal dominant inheritance
- How a dominant mutation causes disease
- Autosomal recessive inheritance
- Consanguinity and recessive disease
- One mutation or two: homozygous vs compound heterozygous
- X-linked recessive inheritance
- Why some "carrier" mothers show mild symptoms
- X-linked dominant inheritance
- When a mutation is lethal in males
- Mendelian pedigree patterns
- Comparing the four patterns at a glance
- Patterns of inheritance
Exceptions to basic Mendelian rules
Real families rarely read the textbook exactly
- Not every pedigree looks textbook-perfect
- Variable expression and genetic anticipation
- Incomplete and age-dependent penetrance
- X-inactivation (lyonization)
- De novo mutations
- Genomic mosaicism
- Segmental mosaicism: type 1 vs type 2
- Loss of heterozygosity in tumor-suppressor genes
- Revertant mosaicism and phenocopies
- Mitochondrial and quasidominant inheritance
- All the exceptions, side by side
- Exceptions to basic Mendelian inheritance patterns
- Exceptions to basic Mendelian inheritance patterns (continued)
- Exceptions to basic Mendelian inheritance patterns (continued)
- Exceptions to basic Mendelian inheritance patterns (continued)
- Pedigrees illustrating Mendelian exceptions
Epigenetics and genomic imprinting
- Genomic imprinting: parent-of-origin matters
- Uniparental disomy
- Genomic imprinting in Prader-Willi and Angelman syndromes
- Epigenetics in cancer
Chromosomal disorders
- When the problem is bigger than one gene
- Too many or too few chromosomes
- Normal female karyotype
- Broken and rejoined: structural chromosome changes
- Translocations and inversions
- How chromosomes are tested
- Chromosomal mosaicism in the skin
Complex (multifactorial) traits
- When genes and environment share the blame
- Alopecia areata pedigrees show a complex pattern
- Twin studies untangle genes from environment
- Genome-wide association studies (GWAS)
- How a genome-wide association study works
- Mapping the whole genome's function
Finding and naming disease genes
- What counts as a mutation?
- Mutation, variant, or polymorphism?
- How family linkage narrows down a disease gene
- Haplotype analysis for linkage refinement
- Confirming what a variant does
- Next-generation sequencing: faster, cheaper
- Choosing a sequencing strategy
- Targeted panels vs WES vs WGS
- Comparison of next-generation sequencing (NGS) options
- No single test rules out disease
- Matching the test to the clinical picture
- Genetic testing strategies
- Genetic testing strategies (continued)
Genetic counseling
- What a genetic counseling visit covers
- When testing comes back negative
- Other things counseling must address
Tumor genetics for the dermatologist
- Two origins of a cancer-causing mutation
- Somatic mutations behind common skin tumors
- Three flavors of germline cancer genes
- Melanoma risk genes
- Testing a tumor sample vs testing blood
- Tools for testing tumor tissue
- When a tumor's mutation flags a family syndrome
- Targeting therapy to the tumor's mutation
- Red flags for a hereditary cancer syndrome
- Surveillance even without a confirmed mutation
- Key takeaways
- References
- References
- References
- References
- References
- References
- Dermatology, 5th Edition (2-Volume Set)