May is ALS Awareness Month: what you should know about it
ALS is the acronym for Amyotrophic Lateral Sclerosis, also known as motor neurone disease (MND) or Lou Gehrig's disease, and it refers to a disease that causes the death of neurons controlling voluntary muscles.
What is ALS?Amyotrophic lateral sclerosis is an always fatal rare neurological disease that involves motor neurons responsible for controlling voluntary muscle movement, like chewing, walking, and talking. The disease is progressive, and nowadays there is no cure and no effective treatment to halt, or reverse, its progression.
In ALS, both the upper motor neurons and the lower motor neurons degenerate or die (Atrophy) over time, and stop sending messages to the muscles which weaken, start to twitch, and waste away leading to muscle weakness, a loss of muscle mass. Eventually, the brain loses its ability to initiate and control voluntary movements.
What are the symptoms of ALS?ALS is difficult to diagnose and it is often diagnosed by ruling out other diseases. The first signs and symptoms of ALS may be so subtle that they are overlooked,The earliest symptoms include muscle twitching, cramping, stiffness, or weakness and they may be related to a simple fatigue. Affected individuals may develop slurred speech (dysarthria) and, later, difficulty chewing or swallowing (dysphagia). Muscles become weaker as the disease progresses, and arms and legs begin to look thinner as muscle tissue atrophies. Individuals with ALS eventually lose muscle strength and the ability to walk. Affected individuals eventually become wheelchair-dependent and increasingly require help with personal care and other activities of daily living. Breathing becomes difficult because the muscles of the respiratory system weaken.
Most people with ALS die from respiratory failure, usually within 3 to 5 years from when the symptoms first appear. However, about 10% of people with ALS survive for 10 or more years.
Causes and types of ALS
It is unclear exactly what causes ALS. There are different types, according to their signs and symptoms and whether or not there is a clear genetic association.
ALS can be sporadic or familial: sporadic ALS occurs randomly, it accounts for 90 to 95% of cases and there is no clear risk factor or cause; familial ALS is inherited (5% to 10% of cases are familial) and the child of a person with ALS will have a 50% chance of developing the condition.
Other possible causes of ALS include:
- Disorganized immune response: The immune system may attack some of the body’s cells, possibly killing nerve cells.
- Chemical imbalance: people affected by ALS often have higher levels of glutamate, which is toxic to nerve cells in high quantities;
- Mishandling of proteins: if proteins are not processed correctly by nerve cells, the accumule can cause the nerve cells to die.
Environmental factors may also play a role: it seems like veterans are more likely to develop ALS, as shown by one study about military personnel. Some possible links have been found between ALS and exposure to:
- Head injury: moderate to severe traumatic brain injury is a risk factor for ALS, even though the association has not been confirmed lately.
- Physical activity: the evidence for physical activity as a risk factor for ALS was limited and conflicting, but often related to soccer and American football are possibly associated with ALS, and that there was not enough evidence to say whether or not physically demanding occupations are associated with ALS;
- Smoking: it is possibly associated with ALS even though the association is not the strongest.
Mutations in several genes can cause familial ALS and contribute to the development of sporadic ALS. Mutations in the C9orf72 gene account for 30% to 40% of familial ALS in the United States and Europe. Worldwide, SOD1 gene mutations cause 15% to 20% of familial ALS, and TARDBP and FUS gene mutations each account for about 5% of cases. The other genes that have been associated with familial ALS each account for a small proportion of cases. It is estimated that 60% of individuals with familial ALS have an identified genetic mutation. The cause of the condition in the remaining individuals is unknown.
About Genetics and ALS
The C9orf72, SOD1, TARDBP, and FUS genes are key to the normal functioning of motor neurons and other cells. It is unclear how mutations in these genes contribute to the death of motor neurons, but it is thought that motor neurons are more sensitive to disruptions in function because of their large size. Most motor neurons affected by ALS have a buildup of protein clumps (aggregates); however, it is unknown whether these aggregates are involved in causing ALS or are a byproduct of the dying cell.
In some cases of familial ALS due to mutations in other genes, studies have identified the mechanisms that lead to ALS. Some gene mutations lead to a disruption in the development of axons, the specialized extensions of nerve cells (such as motor neurons) that transmit nerve impulses. The altered axons may impair transmission of impulses from nerves to muscles, leading to muscle weakness and atrophy. Other mutations lead to a slowing in the transport of materials needed for the proper function of axons in motor neurons, eventually causing the motor neurons to die. Additional gene mutations prevent the breakdown of toxic substances, leading to their buildup in nerve cells. The accumulation of toxic substances can damage motor neurons and eventually cause cell death. In some cases of ALS, it is unknown how the gene mutation causes the condition.
Advantages of getting the Whole Genome Sequencing for ALS
Genetic testing can help determine the cause of FALS (Familial Amyotrophic Lateral Sclerosis) in a family. Testing is most useful in a person who has been diagnosed with ALS. About 60%-70% of individuals with FALS will have a positive genetic test result (mutation identified). Those families with FALS where a mutation is not identified may have FALS caused by a gene or genes that have not yet been discovered. Not having an identified genetic mutation does not eliminate a FALS diagnosis and other family members may still be at risk for developing ALS.
If a mutation has been identified, biological family members who don’t have symptoms can be tested to see if they inherited the genetic mutation; this is called predictive testing. Some medical centers may require a neurological exam, psychological assessment and counseling before predictive testing.
Dante Labs for ALS Awareness Month
Dante Labs decided to be involved in raising awareness of ALS.
Our customer care service will be available to answer your questions and will help you understand the importance of genetic tests.
Also, in order to prevent it, we want to highlight our ALS report, specific for the disease.
Raise the awareness: we are all in this together!