History of CMT4J
The most common inherited motor and sensory neuropathies, composed of a group of pathologically and genetically distinct subtypes ranging from slowly to rapidly progressive disease. CMT is further classified based on the genetic mutation or variant involved – for instance, CMT4A, CMT4B, etc. history
First identified in 1886, Charcot-Marie-Tooth disease (CMT) is an inherited neurological disorder that affects both motor and sensory nerves. It currently impacts approximately 1 in 2,500 people, of all genders and ethnicities. CMT is also known as Another name for CMT, the most common inherited motor and sensory neuropathies, composed of a group of pathologically and genetically distinct types ranging from slowly to rapidly progressive disease. or peroneal muscular atrophy, which are a group of disorders that affect peripheral nerves and the muscles attached to the peripheral nervous system. Peripheral nerves are found outside the brain and spinal cord; their job is to supply the muscles and sensory organs in the limbs with the messages needed to operate correctly. There are many subtypes of CMT, including A variant is a change in DNA. A variant may or may not cause disease. The following modifiers describe the variant: (i) pathogenic, (ii) likely pathogenic, (iii) uncertain significance, (iv) likely benign, or (v) benign depending on whether or not the variant causes disease. For example, a “pathogenic variant” may cause disease. The term “variant” has replaced the term “mutation.” in at least 80 genes that cause the different subtypes of CMT. Symptoms and disease management for each subtype of CMT vary.
Type CMT4 history
All subtypes of CMT4 are inherited in an Inheritance characteristic where a gene is located on a numbered, non-sex chromosome. These are found on one of the 22 pairs of (44 total) autosomal chromosomes in a human body where DNA is stored. This is one of several ways that a trait, disorder, or disease can be passed down through families. These chromosomes are not the sex (X or Y) chromosomes. pattern. Autosomal recessive describes one of several ways that a disorder or disease is passed down through families. An autosomal recessive disorder occurs when two copies of an abnormal gene are passed from each parent to the child.
CMT is further classified based on the A change in DNA that causes disease. involved — for instance, CMT4A, CMT4B, etc.
Type A rare inherited peripheral neuropathy often characterized by rapidly progressive, asymmetrical upper and lower extremity weakness, muscle atrophy leading to handicap, and respiratory issues with no available treatment. CMT4J is a recessive subtype of CMT caused by a variant, also referred to as a mutation, in the FIG4 gene. history
CMT4J is a very rare subtype of CMT. It accounts for approximately one quarter of the 4% of CMT cases that are recessive. First described in scientific literature 100 years earlier, the gene was not identified until 2007, when it was found in patients previously diagnosed with unknown CMT variants. In 2011, a study was conducted that identified almost three times more patients living with 4J. Today, even more patients have been diagnosed with CMT4J outside of this study through the efforts of CureCMT4J, a family foundation and advocacy organization.
Reported cases of CMT4J total approximately three dozen worldwide and make up less than 1% of all CMT cases. Healthy carriers of the The FIG4 gene is the only gene in which pathogenic variants are known to cause CMT4J. gene are more common; the carrier rate of the FIG4 gene among northern Europeans is 1 in 1,000.
It is common for individuals to receive misdiagnoses prior to learning that they are living with CMT4J. People living with CMT4J are commonly misdiagnosed with A neurological disorder characterized by progressive weakness and impaired sensory function. It is considered the chronic counterpart of the acute disease Guillain-Barré Syndrome. CIDP is the most common misdiagnosis for patients living with CMT4J., A neurological disease that disrupts communication between the brain and other parts of the body. Multiple sclerosis is characterized by muscle weakness and difficulty with coordination and balance, so some individuals living with CMT4J are first misdiagnosed with MS., A rare neurological disorder in which the body’s immune system mistakenly attacks part of its peripheral nervous system. GBS presents similar signs and symptoms to CMT4J, including muscle weakness., and A group of rare neurological disorders known as motor neuron diseases. ALS is characterized by the progressive degeneration and eventual death of nerve cells in the brain, brainstem, and spinal cord. ALS presents similar signs and symptoms to CMT4J and is often referred to as Lou Gehrig’s disease., as well as other CMT and neuromuscular diseases, with the primary symptom being muscle weakness due to issues with the muscle fiber (myopathies).
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