Genetic Cause Discovered for Rare Disorder of Motor Neurons

Scientists have finally discovered the genetic cause for a rare disorder of motor neurons, and believe this may help find causes of similar  diseases.  There are many neuromuscular disorders which are caused by disorders in the motor neurons that ultimately damage the nervous system, and can weaken and destroy muscle.  Unfortunately most of these disorders do not have a cure.  The study led by  Professor Andrew Crosby and Dr Meriel McEntagart at St George's, University of London, has discovered the gene mutation that causes a rare disorder of motor neurons called distal hereditary motor neuropathy (dHMN).   dHMN typically affects muscles of the hands and feet, and can causes a hoarse voice. Symptoms usually begin during childhood, but can still appear up to the mid 30s. They used a family of 26 members, all of which carried the mutation but only 14 actually had the disease.   They found that mutation of the gene (SLC5A7)  disrupts the function of a molecule called the choline transporter (CHT). CHT is carries an essential nutrient called choline to the neuromuscular junctions. This disruption to the function of the neuromuscular junctions leads to the debilitating symptoms, and causes dHMN.



The researchers say their findings raise a possibility that mutations of the same gene or genes with similar roles might underlie other disorders involving motor neurons. This will not only open up treatment options for people suffering from dHMN but also potentially for many other terrible diseases relating to the nervous system and motor neurons.