Myotonic dystrophy is a relatively common form of muscular dystrophy, characterized by symptoms evident during adulthood. It is an autosomal dominant genetic disorder, caused by a pathological expansion of CTG triplet repeats within the DMPK gene on chromosome 19q13.3. Typical symptoms of the disorder are muscular weakness, myotonia, cataracts, and heart defects, the severity of which may be related to the number of CTG triplet repeats, often reaching several thousand copies.
Myotonic dystrophy (DM1 & DM2)
NOTE: Our laboratory participates with great success in the external quality assessment scheme organized by the European Molecular Genetics Quality Network (EMQN), which is periodically applied for Myotonic Dystrophy (DM1).
Ο τύπος DM2 της νόσου, που είναι πολύ σπανιότερος, προκαλείται από παρόμοια αύξηση επαναλήψεων της τριπλέτας βάσεων (CTG) στο γονίδιο ZNF9 (CNBP), που βρίσκεται στο χρωμόσωμα 3q21.3.
We apply a specially designed multiplex polymerase chain reaction (PCR) and a triplet-repeat PCR (TR-PCR), for the detection of the precise number of CTG triplet repeats as well as the detection of large triplet expansions at the DMPK gene.
For all prenatal molecular genetic testing, we perform analysis of polymorphic STR markers from a maternal blood sample and the fetal sample, in order to exclude any possible maternal cell contamination. Thus, for prenatal diagnosis, 1-2ml of a maternal blood sample should always accompany the fetal sample (amniotic fluid or CVS).