Pseudohypertrophic macromyotrophy (DMD) is the most common X-linked recessive genetic myopathy in China, with an incidence of about 30/100,000 male infants, and the causative gene is the Dystrophin gene. To date, there is no effective treatment for DMD, only symptomatic management and nutritional support. However, prenatal diagnosis through genetic testing can effectively prevent the birth of children with DMD. The following is a summary of common questions about DMD and brief answers. What are the typical symptoms of patients with pseudohypertrophic macromyotrophy (DMD)? DMD usually starts at the age of 3 – 5 years old, manifesting as slow walking, toe landing, easy to fall, difficulty in going upstairs and standing in squatting position, most of the children have hypertrophy of both lower limbs muscles and walk in duck stance. As the disease progresses, Achilles tendon contracture appears, both feet droop, and it is difficult to walk on flat ground; around the age of 12, the child cannot walk and needs to use a wheelchair. In the late stage, the muscles of the upper and lower limbs, trunk and shoulders are obviously atrophied, and the large joints cannot be straightened and the spine is scoliosis. Most patients die at the age of 20 – 30 due to respiratory infections and heart failure. Why do DMD patients develop muscle atrophy and instead develop limb hypertrophy? After muscle atrophy in DMD patients, the muscle fibers are replaced by fat and connective tissue around them, so the volume increases and the muscle strength decreases. What type of genetic predisposition is DMD? Do both boys and girls in the offspring of patients get the disease? DMD is an X-linked recessive disease that is transmitted to males but not females. The disease is not transmitted to females (carriers) and 50% of the boys will develop the disease. How can I prevent DMD from being passed on to the next generation? DMD is caused by a mutation in the Dystrophin gene. If the parents have had a child with DMD, the child should be tested for the Dystrophin gene and if it is positive, the parents’ genes should be further investigated (usually the mother is a carrier and the father is normal). If the child is a girl, she will not develop the disease; if the child is a boy, an amniotic fluid test for the Dystrophin gene will be performed, and if the test is positive, abortion will be recommended. If the male partner is a DMD patient and the female partner is pregnant and undergoes prenatal genetic testing, under what circumstances should elective abortion be performed? If the male partner is a DMD patient, the female partner should be screened for the Dystrophin gene. If the female partner has a normal gene, the offspring will not have the disease regardless of the boy or girl; if the female partner is a carrier, the offspring will have a 50% chance of having the disease in both boys and girls, in this case, the genetic test should be done by amniotic fluid in early pregnancy, and abortion is recommended if it is positive. When a female carrier of DMD gene has offspring, under what circumstances should she have an elective abortion? If a female carrier has offspring, if the male partner is normal, 50% of the boys will develop the disease and none of the girls will develop the disease; if the male partner is a patient, 50% of the boys and 50% of the girls will develop the disease. Female DMD patients are extremely rare, if the male partner is normal, all offspring will be boys and not girls (carriers); if the male partner is a patient, all offspring will be patients. Is it possible to have offspring if both spouses have the disease? If both spouses have the disease, all offspring will have the disease and offspring are not recommended.