Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability. People with FXS can have developmental delay, learning difficulties, anxiety, autism and epilepsy. The features of FXS vary from mild to severe with males more likely to be severely affected than females because the gene is found on the X-chromosome.



All patients: Medicare rebate (bulk billed): $86.15 (PCR test), $172.30 (Southern blot).

Non-Medicare patients: $101.30 (PCR test), $202.65 (Southern blot).

Reporting time

PCR: 2-3 weeks

Southern blot: 2-3 weeks


Phone: 1300 11 8247
Email: [email protected]

Specimen Requirements

EDTA Blood: Adults/Children: 5 ml

Infants: 1-2 ml

Neonates: 0.5-1 ml

Saliva sample - saliva collection kits are available trough VCGS.

For difficult paediatric collections, a maternal blood sample (CLEARLY LABELLED) can be supplied. Please contact the Lab for more information.


Any patient with a family history of Fragile X syndrome or an inconclusive PCR test will require Southern blot testing.

Genes tested