Monday, July 6, 2015
Inherited Disorders and Birth Defects
Duchenne: Is it a Wrong Diagnosis in my Boy?
My boy has 4.5 years old and he increased CPK level in short time from 1000 (6 months ago) to 8000 (in 2 months ago) and now to 24000. (29 Dec 2009)
Also he has symptoms of DMD, since can`t walk, step up or down, run and jump easily, with a little hard and big calf muscle.
In a genetic laboratory, they diagnose him with DMD for a deletion of exon 51 in his dystrophin gene, and that his mother is not carrier. The methods that they use for this diagnosis, were direct PCR, RFLPs, STRs methods as they claim in the report.
Since we got our only child by IVF, and his mother is not a carrier, I was thinking about these possibilities:
1- wrong diagnosis.
2- mistake in IVF process, and exchanging an egg from an unknown carrier. It means biological mother should be other person.
The second question could be overcome with identification test of parents, but what about the first one? could it be other sickness with symptoms of DMD as mentioned above?
I can provide all other details including results from different labs, if it could help.
Thank you in advance and waiting for your urgent suggestions.
From the information you have given about your son – his big calf muscles, his difficulty walking, climbing, etc and the very high CPK levels - the diagnosis of Duchenne Muscular Dystrophy is correct. And, this was confirmed by the genetic testing that was done that showed that part of the dystrophin gene as been deleted. The part of the gene that is missing (deletion), exon 51, does cause DMD.
Of boys affected with DMD, about 1/3 of the time, the mutation (change) in the dystrophin gene is new in the family and 65% of the time it will be due to a deletion (part of the gene is missing) in the gene. This is called a de novo or new mutation. A de novo mutation is when the change or alteration in the gene happens for the first time in one family member as a result of a mutation in a germ cell (egg or sperm) that formed the child or in the fertilized egg itself.
As your wife had genetic testing and was found not to be a carrier, the most likely cause of the disease is due to a new (de novo) mutation. While it is highly unlikely that the IVF center made a mistake and used someone else’s egg, it is not impossible.
These are important questions. If you have not already done so, I would recommend that you speak to a geneticist or genetic counseling to discuss your concerns. The National Society of Genetic Counselors’ Resource Center can locate a genetics center near you.
Anne Matthews, RN, PhD
Associate Professor of Genetics
School of Medicine
Case Western Reserve University