1.What are the main types of ALS? ALS, whose full Chinese name is amyotrophic lateral sclerosis, is one of the more common types of motor neuron diseases. There are many ways to classify ALS, and there are mainly eight types of ALS according to the symptoms, but from the genetic point of view, there are two main types of ALS: familial ALS and sporadic ALS; familial ALS means that a relative in the patient’s family has had the disease, while sporadic ALS means that no relative in the family has had the disease, and the patient is the first case in the family or does not know the family history of the disease. The patient has the first case in the family or the family history is not known. 2.What types of ALS are inherited? Familial ALS is definitely hereditary. However, studies have found that nearly 11% of patients with sporadic ALS have been found to have a genetic variation, making the distinction between the two types less clear. 3. Is it possible to determine which type of ALS is present directly from the patient’s family history? Usually, 10%-20% of ALS patients are familial and 80%-90% are sporadic. The judgment is based on whether or not the patient has a family history of the disease, i.e. whether or not the patient’s family has had the disease or someone with a similar disease. If there is such a case, it can be called familial. 4. How can I tell if ALS is sporadic or familial if I do not know the family history? By and large, ALS can be judged as familial if there is a clear family history or if it has been clearly diagnosed as hereditary before; if no family history is known, it is temporarily classified as sporadic. 5.Can sporadic ALS be hereditary? Sporadic can be interpreted as those who do not know their family history, and there are many cases of heredity. In the first case, it is possible that the ALS patient is familial, but due to the separation of relatives, it is not known whether the relatives have had the disease; in the second case, the relatives have similar symptoms, but there is no clear diagnosis of ALS, especially in China, some patients were not clearly diagnosed due to economic and medical constraints in the early years, and finally passed away for unknown reasons. Based on these cases, some of the sporadic ALS patients are still actually inherited from their families due to unclear family history. 6. Is there any difference in the age of onset of the two types of ALS? The age of onset is usually relatively early in familial cases and older in sporadic cases, but this is not absolute. In general, the age of onset of ALS is very wide, ranging from about 20 years old for the early onset to 90 years old for the late onset. The average age of onset is around 60 years, which is the average of the maximum and minimum ages of onset. 7. What are the differences in disease progression and symptoms between the two types of ALS? There is little difference in the rate of disease progression between the two types of ALS, nor is there much difference in symptoms. Therefore, it is not possible to distinguish between the genetic types by disease progression and symptoms. 8. Do the offspring of familial ALS patients always carry the gene that causes the disease? The genes are carried on pairs of chromosomes, half from the father and half from the mother, for a total of 23 pairs. In terms of the type of inheritance, there are autosomal dominant, autosomal recessive and X-chromosome companion genes in ALS. The type of inheritance is autosomal dominant, autosomal recessive, and X-chromosome associated. If the gene is autosomal dominant, the chance of the offspring carrying the gene is 50%, and if it is autosomal recessive, the chance of the offspring carrying the gene is 25%. 9. Do the offspring of familial ALS patients always develop the disease? Whether or not the offspring of a familial ALS patient will develop the disease depends on the type of inheritance and the gene carried. First, the genetic type of ALS determines the likelihood that the offspring will carry the gene, which means the risk of the next generation getting the disease. Secondly, it depends on the type of gene that is carried. A gene with a high prevalence of episomes has a high incidence of disease, while a gene with a low prevalence of episomes may not develop the disease, but only carry the gene.