Chromosomal Microarray Testing

History of Cytogenetic Testing

September 2011

Fluorescence in situ hybridization (FISH) testing came into use in clinical cytogenetics laboratories in the 1990s. The advantage of this technique is that it has relatively high resolution and can see deletions down to approximately 100 kilobases or 100 KB. However, the disadvantage is that you need to know where in the genome to look based on clinical findings. For example, historically a patient with clinical features of DiGeorge syndrome would get a FISH test for the region of chromosome 22 where deletions in this syndrome are common (as is shown in this example). However, chromosomal rearrangements elsewhere in the genome can also produce clinical features that are similar to DiGeorge syndrome. Therefore, the ultimate cytogenetic test would be able to examine the entire genome like a chromosome study, but do it at high resolution like a FISH study. This is where chromosomal microarray testing comes in.

< Previous Slide

History of Cytogenetic Testing

Next Slide >

 

Jump to section:

• Introduction
• History of Cytogenetic Testing
• History of Cytogenetic Testing
• Chromosomal Microarray Testing
• Chromosomal Microarray Data
• 180K Oligonucleotide Microarray
• Limitations of Chromosomal Microarray
• Human Copy Number Variation (CNV)
• Interpretation of Results
• When to Order a Microarray?
• Additional ACMG Recommendations
• Pretest Counseling
• Pretest Counseling
• Post-Test Follow-Up
• Post-Test Follow-Up
• Post-Test Follow-Up
• The International Standards for Cytogenomic Arrays (ISCA) Consortium
• The ISCA Consortium
• Providing Clinical Information
• Conclusions
• Mayo Clinic Cytogenetics Laboratory
• Questions?