Fragile X syndrome (Martin Bell syndrome)

Required sample material

Molecular genetic testing:
3-7 ml EDTA blood, for small children a smaller amount of blood (1-3 ml) is usually sufficient or
extracted DNA

Molecular genetic prenatal diagnostics:
15-20 mg chorionic villus tissue or
15-20 ml amniotic fluid
Plus blood or DNA from the pregnant woman (to rule out maternal contamination)

Chromosome diagnostics:
Heparin blood (adults 5-7 ml, children approx. 5 ml, newborns 1-2 ml)
NH4-Heparinate S monovettes (Sarstedt REF 01.1603) or disposable syringes with approx. 20 to max. 200 µl heparin sodium (5000 I.U./ml) (final concentration 10 to max.100 I.U. heparin/ml sample material).
Please do not send Li-heparin blood or EDTA blood!

Sample dispatch

EDTA blood samples for molecular genetic analyses and extracted DNA can usually be sent unrefrigerated by normal post, as the DNA extracted from the leucocytes is very stable. Intermediate storage (blood max. 7 days) should take place in the refrigerator.

Material for prenatal diagnostics should be sent unrefrigerated by express mail. The sample transport time is of great importance, as cell cultures almost always have to be created. The test material should reach the laboratory within 24 hours.

Heparin whole blood for cytogenetic and molecular cytogenetic analyses should be sent by express without refrigeration. The sample transport time is of greater importance in cytogenetics, as cell cultures almost always have to be created here. The test material should reach the laboratory within 24 hours.

Please send the samples to the following address:

Heidelberg University Hospital
Institute of Human Genetics

depending on the test requested:

Laboratory for Molecular Genetic Diagnostics/
Laboratory for Cytogenetic Diagnostics

Im Neuenheimer Feld 366
69120 Heidelberg

Sample labelling

Please label each sample container clearly with the surname, first name and date of birth of the patient and use our request forms.

The request forms are structured in such a way that we have all the necessary information about the patient and the patient consent form (where required) for the examination order.

Please complete the request forms carefully to avoid unnecessary enquiries and please understand that we cannot accept unlabelled sample containers.

Please bear in mind that we can only carry out genetic analyses if we have the patient's written consent!

Request form for molecular genetics (German) (English)

Further information

OMIM: 309550

Test method:
Molecular genetic clarification by determining the repeat length of the CGG repeat in the FMR1 gene using PCR and fragment analysis.

Processing time:
On average 1-2 weeks
In rare cases, the processing time may be delayed by approx. 2 weeks.

Contact person