2. Cytogenetic Disorders  Numeric Abnormalities  Structural Abnormalities

3. Numeric Abnormalities  Euploid –Diploid –Polypoid  Aneuploid –Monosomy –Trisomy  Mosaicism

4. Structural Abnormalities

5. Cytogenetic Disorders Involving Autosome

6. Trisomy 21 (Down Syndrome)

8. Chromosome 22q11 Deletion Syndrome Velocardiofacial syndrome DiGeorge syndrome

9. Fluorescence In Situ Hybridization (FISH)  Accompanied by karyotyping to increase the power of cytogenetic analysis

10. Fluorescence In Situ Hybridization (FISH)  Advantages of FISH –Number of chromosomes in interphase  DNA probes that recognize chromosome-specific sequences –Subtle microdeletions  22q11 deletion syndrome –Complex translocations

11. FISH

12. Cytogenetic Disorders Involving Sex Chromosomes

13. Single-Gene Disorders with Atypical Patterns of Inheritance

14. Triple Repeat Mutations Fragile X Syndrome

15. CGG repeats: Normal around 29 Premutation 52-230 Full mutation 230-4000

17. Fragile X syndrome  FMR1 gene  FMR protein –RNA-binding protein that regulates protein translation  Higher level of transcripts in the brain and the testis

19. Leber hereditary optic neuropathy

20. Mutations in Mitochondrial Gene

21. Genomic Imprinting

25. Farid A. Ardalan, MD, AP, CP azmoudeh@sina.tums.ac.irIKMC:+98-21-919-2403