Human Genetic Mutations Gene Mutations Small scale one

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Human Genetic Mutations

Human Genetic Mutations

Gene Mutations • Small scale: one gene is affected • Any change to the

Gene Mutations • Small scale: one gene is affected • Any change to the DNA sequence of a gene: Nucleotides/Bases may be added, missing, or changed

Gene Mutations: 2 Types Point Mutation Frameshift Mutation

Gene Mutations: 2 Types Point Mutation Frameshift Mutation

Point Mutation • One base (A, T, C, or G) is substituted for another

Point Mutation • One base (A, T, C, or G) is substituted for another • 3 Possible Consequences: – nonsense mutations: code for a stop, which can produce the wrong protein – missense mutations: code for a different amino acid – silent mutations: code for the same amino acid. • Most common!!

Frameshift Mutation • One or more bases (A, T, C, or G) are added

Frameshift Mutation • One or more bases (A, T, C, or G) are added or deleted • Causes: Cystic Fibrosis • Caused by: – Insertion: adding a base – Deletion: removing a base

Causes of Mutations • spontaneous • occur during DNA replication • Caused by MUTAGENS

Causes of Mutations • spontaneous • occur during DNA replication • Caused by MUTAGENS • physical, ex: radiation from UV rays, X-rays or extreme heat • or chemical (molecules that misplace base pairs or disrupt the helical shape of DNA).

Gene Mutations • KEY IDEA: A mutated gene will make a mutated protein •

Gene Mutations • KEY IDEA: A mutated gene will make a mutated protein • Mutant proteins are trouble! – They do not go where they are supposed to go – They do not do what they are supposed to do

Example: Sickle Cell Anemia Normal Red Blood Cell Sickle Red Blood Cell • Red

Example: Sickle Cell Anemia Normal Red Blood Cell Sickle Red Blood Cell • Red blood cells shaped like a disc • Hemoglobin (protien) carries oxygen to all parts of the body • Red blood cells form an abnormal crescent shape • Hemoglobin (protein) is abnormally shaped • don't move easily through your blood vessels • form clumps and get stuck in the blood vessels

Example: Cystic Fibrosis (CF) • What is it? – Autosomal, recessive disorder • Symptoms

Example: Cystic Fibrosis (CF) • What is it? – Autosomal, recessive disorder • Symptoms – Thick mucus in the lungs and digestive track – Constant lung infections and impaired digestion

Cystic Fibrosis (CF) • Who gets it? – Anyone – Most common in Caucasians

Cystic Fibrosis (CF) • Who gets it? – Anyone – Most common in Caucasians • Prevalence – 1 in ~3, 000 Americans has CF – 1 in 23 white Americans carries the mutant allele!

Cause of Cystic Fibrosis (CF) • The “CFTR” gene is mutated – 3 base

Cause of Cystic Fibrosis (CF) • The “CFTR” gene is mutated – 3 base pairs are deleted • Mutant protein is missing an amino acid and cannot fold correctly vs

Normal CFTR protein: Ion channel in cell membrane

Normal CFTR protein: Ion channel in cell membrane

KEY POINT #2 Mutation of a gene = Mutant protein Dysfunctional proteins cause the

KEY POINT #2 Mutation of a gene = Mutant protein Dysfunctional proteins cause the symptoms of the disorder

Review • What are the two major types of genetic mutations? • How are

Review • What are the two major types of genetic mutations? • How are chromosomal aberrations and gene mutations different? • What are the 4 types of chromosomal aberrations? • What are some types of gene mutations?

Scale Scale Factor Scale Drawings Scale Scale FactorScale Scale Factor Scale Drawings Scale Scale Factor
MUTATION SPONTANEOUS MUTATIONS INDUCED MUTATIONS MUTATIONS Mutations areMUTATION SPONTANEOUS MUTATIONS INDUCED MUTATIONS MUTATIONS Mutations are
Mutations Mutations overview Smallscale mutations Missense mutations NonsenseMutations Mutations overview Smallscale mutations Missense mutations Nonsense
Mutations Mutations Types of Mutations Point Mutations occursMutations Mutations Types of Mutations Point Mutations occurs
GENE Mutations CHROMOSOMAL Mutations DNA Mutations A thirdGENE Mutations CHROMOSOMAL Mutations DNA Mutations A third
GENETIC MUTATIONS Exploring point mutations and chromosomal mutationsGENETIC MUTATIONS Exploring point mutations and chromosomal mutations
Mutations and Genetic Engineering Mutations Types of mutationsMutations and Genetic Engineering Mutations Types of mutations
Genetic Mutations Mutations New inherited traits or mutationsGenetic Mutations Mutations New inherited traits or mutations
Mutations Mutations Mutations are changes in the geneticMutations Mutations Mutations are changes in the genetic
DNA MUTATIONS Advanced Biology MUTATIONS Genetic mutations occurDNA MUTATIONS Advanced Biology MUTATIONS Genetic mutations occur
Gene Mutations Gene Mutations O A mutation isGene Mutations Gene Mutations O A mutation is
Higher Biology Chapter 16 Gene Mutations Gene MutationsHigher Biology Chapter 16 Gene Mutations Gene Mutations
Genetic Disorders Mutations Gene mutations can be eitherGenetic Disorders Mutations Gene mutations can be either
Mutations Changes in the genetic material Gene MutationsMutations Changes in the genetic material Gene Mutations