A SNP microarray (or molecular karyotype) is used to detect microdeletions or microduplications – small changes in the amount of genetic material – across all chromosomes.

It gives more detailed results compared to a standard karyotype or CGH microarray, and is a usual first-line test for investigating causes of developmental delay, intellectual impairment* and autistic spectrum disorder. SNP microarrays can also be used in diagnosis of congenital abnormalities, dysmorphic features, or in prenatal screening of high-risk pregnancies with ultrasound anomalies.

A Medicare rebate is available.

*Please note: A SNP microarray cannot detect fragile X syndrome, a leading cause of intellectual impairment which requires a different type of genetic test to identify. Fragile X syndrome is included in the Virtus Diagnostics 3 gene carrier screen (with cystic fibrosis and spinal muscular atrophy) or in the 553 gene extended carrier panel.