1. Chromosomal Mutations Honors Biology

2. Review: Gene Mutations “Micromutations” Small changes to DNA – One or several bases – Change can be positive, negative, or neutral Can be passed to offspring if in gametes

3. Chromosomal Mutations “Macromutations” Large changes to DNA segments/chromosomes – Can be structural (part of chromosome) – Can be a change in chromosome number (whole chromosome) Usually a meiosis error – So not always a mutation passed from parents to offspring Diagnosable through karyotyping or gene testing

4. STRUCTURAL MUTATIONS

5. Deletion A portion of a chromosome is missing Ex: cri du chat syndrome

6. Duplication A portion of a chromosome is duplicated Ex: Charcot–Marie–Tooth disease

7. Inversion A chromosome undergoes breakage and rearrangement within itself Ex: chromosome 9 inversion leads to infertility in 1-3% of the general population (improper sperm formation in men, spontaneous miscarriage in females)

8. Translocation A portion of one chromosome is transferred to another chromosome Ex: chromosome 9 & 22 – chronic myelogenous leukemia

9. NUMBER MUTATIONS

10. Monosomy Missing one chromosome from a pair/pairs Ex: Turner Syndrome

11. Trisomy Three copies of a chromosome Ex: Down Syndrome