Spinal Muscular Atrophy
The SMA is the name given to a group of inherited disorders characterized by weakness and atrophy of muscles. The disease is transmitted as an autosomal recessive.
Attacking the nerve cells (neurons) that stimulate and control the voluntary muscles, the disease causes deterioration. Because of this, motor neurons located in the spinal cord are no longer able to transmit signals to muscles, which prevents them from functioning normally. Therefore, muscle weakening and atrophy (base). It never affects the intellectual functions.
It may be noted:
* Muscle weakness and low muscle tone.
* (To be completed ...)
A mutation on chromosome 5 is frequently involved (as for many genetic diseases affecting the muscles) but it can also be (very rare) form of a scope on the X that only affects men.
Among the proximal spinal amyotrophy, there are four types (two infantile, juvenile type and adult type):
1. Type I, known as severe infantile spinal muscular atrophy, occurring before the age of 6 months and characterized by the absence of acquisition of the base station. There are subtypes of ASA type I variable severity;
1. type II, or intermediate spinal muscular atrophy, occurring at age 6 to 18 months and characterized by the absence of acquisition of walking;
1. type III, also called juvenile spinal muscular atrophy, occurring after the age of acquisition of walking (after 18 months - 2 years);
1. type IV or adult spinal muscular atrophy, manifested in adulthood. These various forms of the same disease with differences in terms of age of onset, severity of symptoms and prognosis.
The first three types are grouped under the term spinal muscular atrophy (ASI), while the term anterior spinal muscular atrophy (ASA) refers to all four types.
The term Anglo-Saxon SMA (for "spinal muscular atrophy) is also used.
The biggest danger is respiratory disease, pneumonia or other, against which the child fight hard.
* There are alternative types called Bis and Tierce and the classifications from the acute disease (Werdnig-Hoffman for type 1) in the chronic syndrome (Kugelberg-Welander for type 3) through forms intermediaries.
The categories mentioned here are challenged because they are neither objective nor realistic because of differences in quality of life of patients (eg type 3 may be a more serious clinical condition that a type 1a)
prognosis, treatment and evolution
If this type of pathology was seen raising the age of death of such holders (once very early) from improving supported (including through the ventilation but also by appropriate access to computers), illness still greatly affects life expectancy. Certain medications (chemotherapy) seem to give promising results:
* Valproic acid
* And more ...
see also Poliomyelitis