Baylor Genetics is now offering Chromosomal Microarray Analysis (CMA) which is a new method of chromosomal analysis that tests for a large number of genetic disorders in a single sample of blood. Below are some frequently asked questions.

What does the CMA test for?

CMA can detect genomic errors for each of the disorders that are usually identified by karyotypic analysis, including Down syndrome, trisomy 13, trisomy 18, sex chromosomal abnormalities, and other rare genetic disorders reported to be associated with mental retardation and/or physical problems.

What are the benefits of the test?

CMA is an expanded version of the chromosomal testing currently available which detects abnormalities that would not have been identified by karyotypic analysis. If an abnormality is found, the results may provide important information that could help guide the medical decisions for a child.

Will an additional blood sample be needed?

Blood from both parents may also be requested.

How long will the results take?

CMA results are provided to the physician in approximately two weeks. Occasionally the results may take longer.

How much does the test cost? Will insurance pay for the test?

For information on cost, please contact the Financial Office. Payment in full is required at the time of sample submission. Insurance coverage is determined by the insurance company and depends on individual policy limitations and medical indications.

What are the limitations of the test?

CMA is a new and sensitive test. It is possible that the test will detect a genetic abnormality for which currently there may be little medical information available to predict the type of clinical problems that may develop in an individual. While the CMA test is very accurate, not every genomic abnormality (genetic defect) can be detected by the test. For some conditions, genomic gains or losses at a par-ticular locus may represent only a certain percentage of the genetic changes associated with that given disorder. For instance, in some disorders, 99% of the cases may be detected by the test, while for others the detection rate may be 70% or less. For this reason, results from your tests should be thoroughly discussed with clinicians, genetic counselors, and other qualified medical personnel.

Can CMA be used for miscarriages or intrauterine fetal demise?

CMA can be done in these circumstances on any tissue (placenta, products of conception, umbilical cord, skin biopsy) that would be sent for cytogenetic testing. A cell culture, required for chromosomal analysis, is often difficult to grow from these types of samples. Therefore, CMA may be successful when karyotypic analysis fails. We also request parental blood samples be submitted and suggest that karyotypic analysis be performed.

How do I learn more about the CMA test?

If additional information is desired about this test, talk to an obstetrician or genetic counselor. More information about CMA may also be obtained by calling Baylor Genetics at 1-800-411-GENE or by contacting us through this website.