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Dermatology

Basic Principles of Genetics

Built from Dermatology, 5th Edition

The first 25 slides of Basic Principles of Genetics
The first 25 slides, exactly as they appear. The full deck has 96 content slides.

What’s inside

9 sections · 96 slides

  1. 01

    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

    11 slides

  2. 02

    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

    18 slides

  3. 03

    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

    16 slides

  4. 04

    Epigenetics and genomic imprinting

    • Genomic imprinting: parent-of-origin matters
    • Uniparental disomy
    • Genomic imprinting in Prader-Willi and Angelman syndromes
    • Epigenetics in cancer

    4 slides

  5. 05

    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

    7 slides

  6. 06

    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

    6 slides

  7. 07

    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)

    13 slides

  8. 08

    Genetic counseling

    • What a genetic counseling visit covers
    • When testing comes back negative
    • Other things counseling must address

    3 slides

  9. 09

    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)

    18 slides