Singlegene Disorders Classification of genetic disorders Singlegene disorders

Single-gene Disorders

Classification of genetic disorders § Single-gene disorders (2%) § Chromosome disorders (<1%) § Multifactorial disorders (60%)

Pedigree

Pedigree

Pedigree

Pedigree symbols

Types of Mutation class of mutation mechanism frequency examples Genome chromosome 10 -2 / cell aneuploidy missegregation division Chromosome chromosome 10 -4 / cell transrearrangement division locations Gene base-pair mutation 10 -10 / cell point division mutations

Gene Mutation base-pair mutation Nucleotide Substitutions (point mutations) Deletions Insertions

Gene Mutation base-pair mutation Nucleotide Substitutions (point mutations) silent mutations missense mutations (amino acid substitutions) nonsense mutations (premature stop codons) RNA processing mutations Regulatory mutations

Gene Mutation base-pair mutation Deletions and Insertions Ø small number of bases is not a multiple of 3, cause frameshift is a multiple of 3, cause loss or gain of codons Ø larger gene deletions, inversions, fusions Ø insertion of L 1 or Alu element vdynamic mutations – triplet expansion

Genetic disorders with classical Mendelian inheritance Dominant Recessive Autosomal dominant recessive X-linked dominant X-linked recessive

Autosomal dominant trait

Autosomal dominant pedigree

Huntington’s disease

Huntington’s disease

Huntington’s disease

Huntington’s disease

Autosomal recessive trait

Autosomal recessive pedigree

Cystic fibrosis

Cystic fibrosis

Cystic fibrosis

X-linked recessive trait

X-linked recessive trait

X-linked recessive pedigree

Hemophilia

Hemophilia

Hemophilia

Literature Biology, eighth edition, Campbell, Reece Unit three: Genetics Chapter 14: Mendel and the Gene Idea Concept 14. 4: Many human traits follow Mendelian patterns of inheritance Pages 276 – 279