Some mutations in the SACS gene sequence may cause motor problems similar to those found in Charcot-Marie-Tooth disease (CMT). This is revealed by a Brazilian study published on Muscular Disorders.
To date, more than 20 genes have been identified that can be associated with different forms of CMT. Each form of the disease presents different neurological and systemic problems, superimposable with those of other neurodegenerative diseases. Nevertheless, they all share some clinical and biological traits that make it possible to link them all to the same disease.
Those suffering from CMT have a progressive degradation of the axonal section of the nerve cells. This hinders communication between nerve cells and that of peripheral nerves with the central nervous system. All this is manifested by symptoms of motor and sensory character.
In the study "Early-onset axonal Charcot-Marie-Tooth disease two to SACS mutation," a team of Brazilian researchers analyzed the cases of two unrelated men. Both suffered from diseases similar to CMT. At first the Charcot-Marie-Tooth had been diagnosed with them. Nevertheless, neither showed the typical nerve degeneration of the disease.
The researchers performed a complete sequencing of the two men's exome. They found that both patients showed genetic mutations concerning the SACS gene. These mutations had already been linked to the spastic ataxia of Charlevoix-Saguenay (ARSACS), which causes intellectual and physical deficits.
Neither patient showed symptoms typical of ARSACS, despite genetic mutation. In addition, the neuropathy they suffered was very similar to that of CMT, but had never been linked to the Charlevoix-Saguenay.
The finding suggests that mutations in the SACS gene could be associated with axonal sensory-motor neuropathies, but without other neurological symptoms.