One third of the variants involved in Duchenne and Becker muscular dystrophies (BDMD) are de novo mutations.
- Knowing that these diseases are predisposed to germline mosaicism, the team from the Department of Genomic Medicine for System and Organ Diseases at Hôpital Cochin (Paris) found, in their unpublished retrospective series of 332 BDMD families, a germline mosaicism frequency of 8.1% in the 62 families with de novo transmission.
- This team’s review of the literature found an average incidence of germline mosaicism of de novo mutations in BDMD of 8.3% (6 to 40%).
It is therefore advisable to offer prenatal diagnosis to pregnant women who already have a child with DMD or BMD linked to a de novo mutation, in order to eliminate the risk of possible germline mosaicism.
