Neonatal/Paediatric Genetic Tests

Fragile X syndrome (FXS) is an X-linked inherited disorder characterised by developmental delay and intellectual disability. Testing confirms the diagnosis in affected children and can also be offered to other family members who may be at risk of developing FMR1 disorders (late-onset ataxia or primary ovarian insufficiency) or having children with FXS.

Chromosome microarray (also known as molecular karyotyping) is the gold standard for the diagnostic investigation of autism spectrum disorder, learning difficulty, developmental delay and where there are clinical indications of congenital anomalies. This is an advanced genome-wide investigation used to detect sub-microscopic detect loss and/or gain of DNA that are associated with microdeletion and microduplication syndromes but are not readily detectable by conventional karyotype and/or fluorescence in-situ hybridisation (FISH).

Conventional chromosome testing is the applicable for the investigation of syndromes such as Down syndrome, Turner Syndrome and reproductive health.

Conventional cytogenetic analysis involves the analysis of the whole genome at the cellular level to detect large genomic changes and chromosomal rearrangements. This test involves culturing white blood cells to produce metaphase spreads of chromosomes, from which slides are prepared and representative cells are captured into digital images.

Fluorescence in-situ hybridisation (FISH) is a targeted molecular cytogenetic technique used for the investigation of specific chromosome regions involved in the particular syndrome. The technique binds a colour labelled DNA probe to a specific region on the patient chromosomes.

As this is a targeted test it is important when requesting a FISH test to indicate the clinical condition that is being tested for.

Specific Microdeletion Probes