Established and basic genetic testing

Chromosome analysis is one of the classical and established methods of human genetics. The examination of chromosome sets is used in various medical fields: For example, in the suspected diagnosis of a Down or Turner syndrome, in the presence of a conspicuous prenatal ultrasound finding or in the diagnosis of haematological neoplasia. The aim of chromosome analysis is to examine a set of chromosomes (example of a female karyotype) for numerical or structural changes. Deviations in the normal number or structure of chromosomes can be the cause of infertility, miscarriages or malformation syndromes.

In addition, neoplastic cells may exhibit specific chromosomal changes. Therefore, chromosome analysis is still an obligatory examination method in leukaemia and lymphoma diagnostics, in addition to new laboratory diagnostic procedures. The detection of numerical or structural changes plays an important role for the initial diagnosis as well as for the further course of the disease and the WHO classifications. The karyotype of leukaemia cells is often an independent prognostic parameter.

Tumor cytogenetics

Common indications for postnatal chromosome analysis:

  • Unclear mental retardation or retardation of development, e.g., short stature
  • Multiple congenital malformations
  • Subfertility/infertility
  • Habitual abortions
  • Familial chromosomal changes
  • leukemia, lymphoma, or plasma cell disease

Metaphase FISH

Indications for prenatal chromosome analysis:

  • Increased maternal age
  • ultrasonic abnormalities
  • Chromosomal abnormalities in previous child
  • Chromosomal structural changes in parents
  • Striking results of biochemical tests such as first trimester screening, integrated screening or other screening tests, e.g. non-invasive prenatal test (Harmony Test).

Preanalytics

Since vital cells are required for chromosome analysis, rapid sample transport is required for successful cell cultivation. If possible, cytogenetic tests should be shipped within 24 hours and by our transport service, as an extended transport time impairs the sample quality. A prior registration of the samples (especially before weekends and holidays) makes it easier for us to plan the cell culture and thus accelerates the examination procedure. All materials used for cytogenetics should be stored at room temperature before and during transport and should not be frozen.

Chromosome analysis
Material
TAT (after sample receipt)

Prenatal

Amniotic fluid

Approx. 10 - 15 ml amniotic fluid (discard the first 2 ml), store and transport at room temperature.

Never centrifuge!

8 - 10 days
Chorionic villi (CVS)  

Approx. 20 - 30 mg chorionic villi, for transport use sterile medium*.

Direct preparation: 1 - 2 days
Culture:                         8 - 10 days
Cord blood  

2 - 3 ml umbilical cord blood in Lithium Heparin tubex.

7 days
Product of conception (POC)

Chorionic villi, parts of umbilical cord, Achilles tendon, fascia lata. Use sterile transport medium*.
Do not give in formalin!

10 - 14 days

Postnatal

Blood

Lithium Heparin blood
newborns:                         1 - 2.5 ml
children and adults:      5 - 7 ml

 

14 - 21 days;
Urgent cases: 7 - 10 days
Fibroblasts

Skin biopsy, approx. 5 mg / 2 - 10 mm² of tissue. For transport use sterile medium*.
Do not give in formalin!

14 days

Tumor cytogenetics

Bone marrow (Minimum of 10 x 106 mononuclear cells)

 

5 - 10 ml heparinized bone marrow aspirate 8 - 10 days

Leucemia blood (amoutn of blasts ≥ 20 %)

 

5 - 10 ml heparinized peripheral blood 8 - 10 days

* Available via our local agents; alternatively a sterile-coated tube with physiol. NaCl and antibiotics (Penicillin 100 µg/ml, Streptomycin 100 µg/ml or Gentamycin 50 µg/ml) can be used.

To exclude maternal cell contamination, an EDTA blood sample (2-3 ml) is additionally required (Reference shipment).

 

For further questions regarding the material or the cytogenetic test list please contact us at 06132/781 411.For further questions regarding the material or the cytogenetic test list please contact us at +49 6132 781 240.

 
 

"You want to know more about our cytogenetic diagnostics?"

Contact me: anja.kron@bioscientia.de or +49 6132 781 240
Dipl. Biologist Anja Kron, Head of Cytogenetics