Is ALS a hereditary disease?

ALS as a hereditary disease: facts and myths

The first thing we must clarify is that, fundamentally, the ALS (Amyotrophic Lateral Sclerosis) It is not a hereditary disease. So far, at least the 90% of cases are considered to be Unknown cause . In fact, this is the reason why there is research to determine the causes of this muscular ailment, which, remember, progressively impedes mobility until assisted respiration becomes necessary.

What happens with ALS is similar to what happens with many other diseases, including cancer , where there is a percentage that is due to genetic causes and another that is due to other factors or unknown causes. The good news is that, in the part of genetic origin, there is a previous study of what the causes are. mutations that have the greatest influence. This way, it's possible to conduct a preliminary analysis for an accurate diagnosis and to identify future possibilities.

Therefore, we cannot ignore the fact that in some cases there is a genetic correlation. And, since this disease has no cure, it's important to determine the extent of it. Here we provide more details about this condition:

What percentage of ALS is a hereditary disease?

It is estimated that a 10% of cases of ALS have a a hereditary factor , of genetic origin. In this case, we can indeed speak of hereditary ALS (FALS). What's more, 50% of the children of people who have had hereditary ALS are likely to inherit this genetic mutation. As we can see, this situation could be repeated for several generations, which is why it's so important to verify whether the ALS is of genetic origin or not.

This percentage is common in other multifactorial diseases, so it's not surprising. The important thing in this case is also the reproduction in several generations, which can be especially problematic. Added to this is the fact that detection is often late and after some symptoms are already evident.

They exist genetic testing that can focus on specific genes. This way, it's possible to confirm or rule out that genetic variant. And, when it comes to planning future offspring, this is especially important.

What mutations can cause hereditary ALS?

There are numerous genes that mutate when ALS is inherited. In order of incidence and importance, we highlight the following:

• The mutation in the SOD1 This is the most common, as it occurs in 15% of hereditary cases. In this case, since the enzyme doesn't function, the protection of the nerve cells is eliminated, and motor neurons are progressively killed.
• The C9orf72 gene, which also occurs in some dementias, is common in some ethnic groups, and its replication also influences the development of this disease. Since this circumstance occurs more frequently in certain groups, it is more interesting to focus on this.
• The gene When TARDBP mutates, it hinders the correct coding of the TDP-43 protein and, consequently, messenger RNA. This, of course, also creates problems.
• Mutations in the gene FUS , or fusion proteins, are more unusual and also influence RNA transport, which creates problems. This is another factor that could contribute to the development of ALS.

However, it should be noted that, at present, it is estimated that there are up to 20 genetic mutations that could influence FALS. Therefore, if there is any suspicion, early testing is the smartest course of action.

What environmental factors exist beyond genetic inheritance?

Although we are still at a relatively early stage of research, there are some environmental factors that can influence ALS. These are particularly true:

• Smoking: Smoking is a risk factor for ALS. And the percentage of people with this disease who have been smokers is higher than the general population, enough to warrant consideration.
• Exposure to pollutants: There are several pollutants that contribute to ALS. They range from polluted air to pesticides, including lead and mercury particles. However, this is still a very broad field of study. This is due, among other things, to the fact that exposure to pollutants is becoming increasingly widespread.
• Work in the army: For some reason, people who have been in the military or who have worked in the military for long periods of time have more cases of ALS. It's suggested that exposure to certain pollutants could be one reason.
• Unhealthy diet: Consuming sufficient vitamins is essential for the body to function properly. An unbalanced diet could increase the likelihood of developing ALS.
• Lack of physical activity: As with other types of diseases, the lack of physical illness could be a risk factor.

In any case, it is hoped that in the coming years we will be able to gain in accuracy in inferring solid causes and consequences.

Is there any gender bias in ALS?

Although ALS can affect both men and women, it does seem that there is a gender bias towards the Men . Specifically, before the age of 65, there are more cases of ALS in men than in women. However, after that age, the proportion of cases is similar in both genders.

Are there any ailments or injuries that contribute to ALS?

It appears that people who have suffered some type of severe head injury are more likely to develop ALS. In this context, there may be some contributing factor to the increase in cases, but, so far, we lack information.

Does age influence ALS?

Yes , as with many other diseases, being of a certain age increases the likelihood of suffering from ALS. For example, cases multiply from the age of 60 , being much less common (although not unusual) before reaching that age.

In summary…

The factor of ALS as a hereditary disease, although rare, exists in a sufficiently high number of cases. Want to clear up any doubts? Genotics You'll find various genetic tests that can help rule out this origin. Check out our portal!