1. If a relative has ALS, is it clear that the disease is familial? Is there still a need for genetic testing? If the patient has a clear family history, it is familial. For example, if there are several generations of ALS in a family, it means that the family group is clear and it is relatively easy to confirm the diagnosis. The first purpose is to determine the final diagnosis through genetic testing; the second purpose is to identify the causative gene for ALS through genetic testing. Only when the causative gene is identified will there be a basis for prenatal diagnosis to prevent similar diseases in the next generation. 2. If there are ALS patients in my family and I have been screened for the relevant gene, but I do not have the disease at present, is it necessary to do genetic testing to predict whether the disease will develop? This is called pre-symptomatic testing in genetic counseling. If I am in my 20’s when I come for counseling, the age of onset of the type of ALS itself may be around 60 years old. If the person tests positive at this time, the 40 years of life without the onset of the disease will be quite difficult; even if the person is lucky enough to test negative, it does not mean that the person will not develop the disease. Therefore, from an ethical point of view, since the person does not know what the results of the genetic test will be before he/she does it, he/she needs to think it through and clarify what the purpose of the test is. Usually, in genetic counseling, the doctor will not directly say whether to do pre-symptomatic testing, but will teach the person to be tested such medical and genetic knowledge and ask him/her to think about what the results of the genetic test will do to him/her. 3.If I have ALS in my family but have not been screened for the disease, is it necessary to do the genetic test if I do not have the disease? If there is an ALS patient in the family, but no genetic screening has been done, and the results of the genetic test are not known, and the patient does not have the disease, then the genetic test is a blind test, and doctors usually do not recommend blind screening. In addition to the ethical reasons mentioned earlier, there is also the issue of cost. There are 29 genes that can be identified and more than 100 reported susceptibility genes. Blind screening requires more genes to be tested than general diagnosis, and all the susceptibility genes need to be checked. Of course, some people can afford it, but the most critical thing is that there is a huge amount of information analysis work to be done on these genes, which requires huge human and material resources, so even if you are willing to spend 200,000 to 300,000 to do such a blind screening, there may not be people or institutions willing to do so. 4. Generally speaking, which family members need genetic testing? Do only immediate family members need to be tested? If someone in the family has had ALS, it is necessary to do genetic testing for relatives who have developed the disease or have similar symptoms, as long as they are related to each other, whether they are first or second generation relatives or even third generation relatives. 5. If the type of disease detected is likely to develop, how long does it usually take to develop? The age of onset and symptoms as well as the prognosis depend on the genetic type of the gene, for example, if it is the SOD1 gene variant, it will cause more damage to the lower motor neurons and muscle atrophy and muscle weakness will be more obvious, but the degree of cognitive dysfunction will be less severe. In case of C90RF72 gene variant, in addition to muscle atrophy and weakness, there may be changes in personality, language and other cognitive functions, and the survival period of patients is relatively short. In other words, each pathogenic gene has different age of onset and different clinical manifestations and prognosis. In particular, there is a family of SOD1 gene called H46R gene, and patients in this family only have 10-20 years of survival after the onset of the disease; in the United States, there is a gene called A4V, which also belongs to a mutation type in SOD1 gene, and the average survival of ALS patients of this type is less than 1 year. 6.Is there any way to slow down the onset of the disease? Do you think it is useful to delay the onset of the disease by taking medication or health supplements? I often encounter such people in clinical clinics, but there is no way to prevent or delay the onset of the disease. The most basic and fundamental means of prevention is prenatal diagnosis through prenatal testing to prevent the birth of a child with the gene that causes the disease.