Test Description:
Autism is etiologically heterogeneous. A percentage of individuals who present with autism are found to have an abnormality that can be detected via high-resolution chromosome analysis, SNRPN duplication analysis, subtelomere analysis, or molecular analysis for fragile X syndrome. Please note that a number of other genetic conditions may also present with autism or autistic-like features. Most cases of autism are considered idiopathic.
Methods:
High resolution metaphase cells (band resolution of 630 or higher) are analyzed during this study. To analyze subtelomeres, a multi-probe FISH test for subtelomeric integrity is performed using the Telvysion telomeric probe set from Vysis, IL. The probe set involves 15 separate FISH probe mixtures, analyzing 5 or more metaphase cells from each mixture. This tests the subtelomeres on the short (p) and long (q) arms of all the chromosomes individually, with the exception of the p arm subtelomeres of the acrocentric chromosomes (13, 14, 15, 21, and 22); deletions of the p arms of these chromosomes are generally not deleterious. Rearrangements, deletions and duplications may be identified via testing.
A fluorescence in situ hybridization (FISH) probe specific to the q11.2 region on chromosome 15 (SNRPN, supplied by Vysis, IL) is utilized for this study. At least twenty metaphase cells are analyzed for duplication detection. We are also able to identify deletions for this locus, which are associated with Prader-Willi and Angelman syndromes. These tests were developed by Vysis, IL. The Michigan State University Cytogenetics Laboratory has established and verified this test's accuracy and precision as required by the CLIA 1988 regulations. It has not been cleared or approved for specific uses by the U.S. Food and Drug Administration. However, the FDA has determined that such clearance is not necessary to use this test for clinical purposes.
Fragile X syndrome analysis is performed through the MSU DNA Diagnostic Laboratory. Please see our fragile X test test entry separately for specific test methods.
Specimen Requirements:
20 mls of whole blood in a sodium heparin tube (green top) and 20 mls in an EDTA tube (purple top).
Shipping Instructions:
Ship immediately or via overnight delivery at room temperature to the MSU Cytogenetics Laboratory, B123 Life Sciences Bldg, East Lansing, MI 48824. For specimen transport, call 517-353-2032 or 1-877-TEST-DNA. For specimens obtained on the weekend, call our pager at 517-229-6130. Please leave a return phone number and our weekend staff will contact you.
Turnaround Time: 3-4 weeks