In the prenatal setting, many women who undergo an invasive procedure (eg chorionic villus sampling [CVS], amniocentesis) will have their sample analysed using a CMA (in addition to fluorescence in situ hybridisation [FISH] or quantitative fluorescence polymerase chain reaction [QF-PCR]). General practitioners (GPs) working in this area may see the results from CMAs; the section on interpretation of results below may be useful.
There are no clear guidelines about whether GPs should be ordering CMAs for investigating DD or ID in children. A CMA has been identified as a first-line test for investigating non-syndromic DD and ID.2 A Medicare Benefits Schedule (MBS) rebate is available for CMAs in the paediatric setting where a patient has DD, ID, ASD or at least two congenital abnormalities.
While GPs are able to order CMAs themselves, many choose not to given the complex interpretation of the results. However, ordering a CMA (together with an FXS test) alongside a referral to a specialist can reduce waiting times for patients. It is important to note that microarrays will not identify FXS; a separate DNA test is required.