Conventional G-banded chromosomal analysis

Conventional cytogenetic analysis (karyotyping) identifies chromosomal changes including balanced and unbalanced structural and numerical abnormalities. This test is often used in cases of recurrent spontaneous pregnancy loss and in cases where a gross chromosomal change is suspected. Testing typically takes from ~7 days (blood specimens) to 10-20 days for specimens requiring prolonged cell culture (amniotic fluid and other tissues, including post-mortem specimens).

Molecular karyotyping (microarray)

Molecular karyotyping identifies cytogenetic imbalances smaller than that detectable by conventional karyotyping. This testing detects copy number changes due to aneuploidy, deletions or duplications. Balanced rearrangements will not be identified. This test is used commonly for investigation of developmental delay and autism-spectrum disorders, and in situations where small chromosomal change is suspected. Molecular karyotyping results are usually available within 7 days (prenatal and urgent blood specimens) to 3-4 weeks.

Fluorescent in situ hybridisation studies (FISH)

Aneuploidy Detection

Interphase FISH (iFISH) is a rapid screening test to detect aneuploidy for chromosomes 13, 18, 21, X and Y. Results are typically available within 2 business days of receiving specimens within the laboratory. In critical situations results from blood specimens may be obtained within 4-6 hours (by arrangement with the laboratory).

Microdeletion Detection

FISH testing is available for a range of chromosomal microdeletion syndromes .The more common of these includes DiGeorge/Velocardiofacial syndrome (22q11.2), Williams-Beuren syndrome (7q11.23), Cri du chat syndrome (5p15.2) and Steroid sulfatase (STS) deficiency (Xp22.3). Results from this testing is typically available within 2-7 days.

Chromosome breakage syndromes

Specialised testing to detect chromosomal correlates of Fanconi Anemia and Ataxia Telangiectasia is available by arrangement with the laboratory. These tests are highly complex and require appropriate controls. Consequently prior notice for these requests is essential. Results may take up to 3 weeks.

Tissue culture for cryopreservation or transport

The laboratory has extensive tissue culture facilities and expertise. Cell cultures can be established for cryopreservation and future study or for transport to other testing laboratories.