Is ALS hereditary?

When talking about ALS, many people will think of the famous scientist Stephen Hawking, who has made remarkable achievements in the field of astrophysics theory. But at the same time, he has been fighting ALS for nearly half a century.

ALS is a rare disease. Foreign studies show that about 4-6 people out of every 100,000 may suffer from the disease. The incidence of ALS is not high, but the mortality rate is very high. There is no effective treatment, and it is one of the five most incurable diseases in the world.

Clinically, "ALS" is the common name for motor neuron disease. Due to the death of motor neurons, the brain cannot control muscle movement, and patients gradually experience muscle weakness, muscle atrophy, dysphagia, and other phenomena, and gradually lose their ability to move and take care of themselves until death. Although the whole body of "ALS" is paralyzed, the sensory nerves are not damaged, so the patients still have normal intelligence, memory and perception. This also makes many ALS patients watch their body functions continue to deteriorate while they are conscious.

Is ALS hereditary?

In recent years, some new studies at home and abroad have shown that from a genetic point of view, there are two types of ALS: familial and sporadic. Familial "ALS" refers to the patient's family relatives suffering from the disease; sporadic "ALS" refers to no relatives suffering from the disease, the patient is the first case in the family or the family history is unknown.

Will the descendants of people with familial ALS definitely carry the disease-causing gene?

Genes are carried on pairs of chromosomes. Half of each pair of chromosomes in human cells comes from the father and half comes from the mother, for a total of 23 pairs. Among them, 22 pairs of chromosomes are carried by both men and women, called autosomes. Only the 23rd pair of chromosomes has gender differences. Women carry two X chromosomes, and men carry one X chromosome and one Y chromosome. In terms of genetic type, there are many ways of inheritance of "ALS", including autosomal dominant inheritance, autosomal recessive inheritance, and X-linked inheritance. Whether the offspring will carry the disease-causing gene depends on the genetic type of the disease-causing gene. If it is autosomal dominant inheritance, the offspring are more likely to carry the gene. If it is autosomal recessive inheritance, the probability of the offspring carrying the disease-causing gene will be relatively reduced. Therefore, for patients with familial "ALS", whether their offspring will develop the disease depends on their genetic type and the gene carried by their parents.

How to prevent ALS?

The best way to prevent ALS is early detection, early diagnosis, and early treatment. ALS will cause muscle weakness in the early stages. Many people have experienced muscle weakness in daily life, but don't panic too much, because not all people with muscle weakness will develop into "ALS". The causes of muscle weakness may also be nutritional factors, mental stress, food contamination and poisoning, viral infection, endocrine disorders, etc. Therefore, it is very important for everyone to develop the habit and awareness of regular physical examinations and paying attention to health.

This work is original to "Science Popularization China - Scientific Principles at a Glance". Please indicate the source when reprinting.