For the first time, and thanks to a family with several affected people, Canadian and Finnish researchers have provided evidence of the involvement of mitochondrial DNA in a scapulo-peroneal syndrome:
- the initial diagnosis was that of an atypical Charcot-Marie-Tooth disease without molecular signature,
- an exhaustive high-throughput sequencing (NGS) study had previously eliminated any anomaly in the Mendelian genes known to give rise to a scapulo-peroneal syndrome (PMP22, TRPV4, MORC2, among others)
- a few ragged red fibers and several Cox-negative fibers had been observed under the microscope, without them appearing to be specific given the age of the proband,
- a large deletion of mitochondrial DNA was finally demonstrated through additional studies.