Tests for adults
Samples should ideally be sent to the Cytogenetics Department on the same day/next day. Where a delay is inevitable, such as over weekends, please store the sample in a refrigerator before sending on the next working day but please DO NOT FREEZE. Lithium heparin and EDTA tubes are suitable for cytogenetic testing depending on the test required, please see below, samples in other tubes will be rejected. For sample labelling, sample tube guide and completion of referral form criteria please see referral requirements.
Karyotype and FISH
Please send a 2-4ml blood sample well-mixed in a lithium heparin (green cap) tube. You may also wish to refer a POC/placental sample for recurrent pregnancy losses, please see solid tissues.
Please send at least 2ml of blood, well mixed, in a lithium heparin (green cap) tube. Please note that from April 2021, Fanconi Anaemia referrals should be sent to Sheffield Diagnostic services. Please see SDGS website for details.
Acceptance and rejection criteria
Lithium heparin is the preferred tube for karyotype testing. Bloods received in EDTA will be processed but the quality may be compromised. Bloods received in any other tube will not be processed.
For microarray testing, blood in any tube other than EDTA will not be processed. The preferred volume is larger than 1ml, however for smaller volumes processing will be attempted but the test may be unsuccessful.
Referral categories and tests
- Recurrent (3 or more) pregnancy losses (blood samples from both partners, where no POC is available)
- Male patients with: azoospermia, oligospermia or asthenospermia
- Male patients with features of Klinefelter syndrome
- Couples experiencing prolonged infertility or sub fertility (blood samples from both partners)
- Female patients with primary or secondary amenorrhoea or features suggestive of Turner syndrome
- Female patients with premature ovarian failure/premature menopause
- Family history of chromosome abnormality or rearrangement (including those detected antenatally)
- Patients with family members with features suggestive of a chromosome abnormality
- Pregnancy loss/termination with abnormality detected on scan (blood samples from both partners)
- Features of chromosome instability
- Inheritance studies following tests on other family members
Please note, if a patient or partner is pregnant, or there is another clinical need for urgency please indicate this on the referral form.
FISH - Fluorescence In Situ Hybridisation
We have a number of FISH probes available - please see available constitutional FISH probes. For specific exclusion of the syndromes mentioned on the available FISH test list please indicate on the referral card which syndrome is to be tested for. For other FISH tests please contact the department to discuss your requirements. Please note, that microarray analysis for probands suspected to have a microdeletion syndrome is a more appropriate test. Please see neurodevelopmental disorders.
Microarray is undertaken in place of karyotype analysis where the patient meets some of the following criteria:
- Developmental delay or learning delay
- Learning disability
- Facial dysmorphism or congenital abnormalities
- Behavioural problems/autistic spectrum
As well as the above categories, microarray may also be requested for inheritance studies following tests on a family member. Please refer to the link for neurodevelopmental disorders.
Chromosome Instability Syndromes
We offer an urgent test for Fanconi Anaemia (for which we require at least 2ml of blood in lithium heparin). Tests for other chromosome instability syndromes (Bloom syndrome, Ataxia Telangiectasia, Nijmegan Syndrome) are offered by other laboratories. Please contact the Cytogenetics Department to discuss your requirements.
Please see our reporting timetable.
Please see our postnatal limitations of testing.
Storage and further testing
Fixed material from adult referrals is kept for 6 months from receipt date of the sample. After this time cases with a normal karyotype are discarded; cases with a structural chromosome abnormality are stored for 5 years.
Page last updated 28/10/2020. Please note that if printed, the information is only valid on the day of printing.