1 / 31

Dr. Derakhshandeh, PhD

Mutation Screening. Dr. Derakhshandeh, PhD. TYPE OF MUTATIONS. WHICH TECHNIQUES DETECT WHAT TYPE OF MUTATIONS In classical genetics, three types of mutations are distinguished:. Different types of mutations. genome mutations: changes in chromosome number

zahir-hart
Download Presentation

Dr. Derakhshandeh, PhD

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Mutation Screening Dr. Derakhshandeh, PhD

  2. TYPE OF MUTATIONS WHICH TECHNIQUES DETECT WHAT TYPE OF MUTATIONS In classical genetics, three types of mutations are distinguished:

  3. Different types of mutations • genome mutations: changes in chromosome number • chromosome mutations: changes in chromosome structure • gene or point mutations: mutations where changes are at molecular level

  4. genome mutations: changes in chromosome number

  5. Techniques Karyotyping, conventional cytogenetics

  6. Down Syndrome (Trisomy 21( Trisomy 2(

  7. chromosome mutations: changes in chromosome structure

  8. CHANGES IN CHROMOSOME STRUCTURE • Translocations • Large Deletions/Insertions • Inversions • Duplications/Amplifications

  9. Techniques • Conventional cytogenetics • molecular cytogenetics FISH • Molecular: • PFGE, Southern blotting, Northern BlottingFluorescence Dosage analysis • large deletions • Insertions • duplications

  10. Interphase FISH Examples 18 (aqua),X (green), and Y (red). 13 (green), and 21 (red)

  11. gene or point mutations: mutations where changes are at molecular level

  12. Methods for detection of known mutations • Methods for detection of unknown mutations

  13. Methods for detection of known mutations • PCR and size separation eg. DMD • PCR and restriction enzyme digestion eg. SMN exon 7 & 8 • Allele specific amplification (ASA) • Allele refactory mutation system (ARMS) eg. CF • Allele specific oligonucleotide hybridisation (ASO) • Dot Blot eg. CF • DNA chips eg. Brca1 • Genomic DNA sequencing

  14. ARMS Amplification Refractory Mutation System Allele Specific PCR (ASPCR) PCR Amplification of Specific Alleles (PASA)

  15. Uses • Population screening • rapid (1 working day) • inexpensive • non-isotopic • Used for testing for • B-thalassaemia • Cystic Fibrosis • Sickle-cell anaemia • Phenylketonuria • Apolipoprotein E, etc

  16. Modifications/Adaptions to the original ARMS methodology • Multiplex ARMS

  17. To set up multiplex ARMS • Determine commonest mutations in the population • develop the muliplex ARMS these mutations • validate the results of the multiplex test on samples with another methology

  18. Agarose gels showing the feasibility of the ARMS concept

  19. ARMS-PCR 1 23 45 67 89 1011 12 N M N M N M N M N M N M

  20. Methods for detection of unknown mutations

  21. Methods for unknown mutations (diagnostic methods) • These methods are relatively simple, but still require: • experience and skill to perform.

  22. BRCA

  23. BRCA1 Gene

  24. BRCA2 Gene

  25. SSCP single strand conformation polymorphism • simplicity • clearly by heteroduplex analysis (HA)

  26. Pedigree of a selected family with breast cancer

  27. SSCP AnalysisBRCA1 Exon 15, 4650delCA

  28. Pedigree of a selected family with breast cancer

  29. SSCP AnalysisBRCA1, Exon 20,Nt 5382

  30. SSCP AnalysisExon 11pi BRCA1 MS R1347G

  31. A woman having amniocentesis

More Related