Kennedy disease (KD), also known as X-linked spinal cord myelomeningocele (SBMA), is an X-linked recessive disorder in which the causative gene is the androgen receptor (AR) gene located at X q11-12. The first exon of the AR gene has a CAG repeat sequence that encodes a polyglutamine (PolyQ) chain. The number of this repeat sequence ranges from 9 to 36 with an average of 21 in healthy individuals, while the number of CAG repeats in KD patients ranges from 38 to 62. Like many types of spinal cerebellar ataxia (SCA), Huntington’s chorea (HD) and eight other diseases, KD is also a CAG repeat sequence disease. the prevalence of KD is 1 to 2/100,000, and it is estimated that there are about 20,000 to 30,000 patients with KD in China. Female heterozygotes or pure heterozygotes carrying the abnormal gene do not develop the disease or have only subclinical manifestations, so the patients are all male. The mean age of presentation of limb weakness is 42 years, and the age of onset is related to the degree of abnormal abnormality. Patients usually have nonspecific symptoms such as tremor for more than 10 years prior to myasthenia gravis. kd progresses slowly, with foreign studies showing that patients have 20 to 25 years of disease from the onset of limb weakness. As the disease progresses, it gradually requires support or even a wheelchair, which seriously affects the quality of life. Despite the lack of sensory symptoms, both electrophysiological and pathological studies show that patients have involvement of the dorsal root nerve nodes and sensory nerve axons. In addition, patients may present with clinical manifestations other than the nervous system such as male breast development and abnormal lipid metabolism, confirming that KD is a disease that involves the whole body. KD is a single-gene genetic disorder with a clear etiology, but the pathogenesis is still not well understood. Abnormal intranuclear inclusion bodies were seen in the residual spinal anterior horn motor neurons of the patient, and it was hypothesized that the deposition of inclusion bodies in the nucleus was responsible for the apoptosis of motor neurons. In recent years, applying high-resolution atomic force microscopy, conformationally abnormal oligomers can be found in the cytoplasm and nucleus of motor neurons from KD patients, and the oligomers cause misfolding of AR proteins, affecting their function and generating new toxicity. These are the two main theories regarding the pathogenesis of KD. Regardless of the theory, it is believed that the pathogenesis of KD is closely related to androgens, the ligands of AR. Androgens can accelerate the progression and pathological changes in KD transgenic rats, and pharmacological or surgical depot treatment can result in significant improvement of muscle weakness symptoms and return to normal lifespan in KD transgenic rats. Currently, there are six clinical studies on KD treatment, four of which are related to androgen suppression therapy, and three of which use leuprolide acetate, a testosterone inhibitor. “leuprolide acetate”. Among these studies, the highest design level was the JASMITT study (multicenter randomized double-blind placebo-controlled design with a sample size of 199 cases and 1 year of “leuprolide” treatment). The results showed significant differences in CK levels and ALSQ-5 scores in the treatment group compared to the control group. In patients with 10 years of disease, leuprolide significantly delayed the deterioration of ball function. Treatment of KD patients with dutasteride, a dihydrotestosterone inhibitor, was not effective. “Although clenbuterol improved 6-minute walking ability at 3 and 12 months, it did not improve muscle strength and ALS scales, and led to increased CK levels. Although there is still a lack of convincing evidence, leuprolide is still the most studied drug. “Although leuprolide has not been effective in some studies and does not improve the disease but only delays its progression, it is still the only drug that has been studied in clinical trials. However, it remains the only drug that has made a statistically significant difference in the primary endpoint in clinical studies, and the earlier patients use it, the greater the potential benefit. “Leuprolide is administered by subcutaneous injection once every 28 days and costs about $1500 to $1900. Unless side effects or drug-related adverse reactions occur, patients need to use it for a long time. In another clinical study on aerobic training, investigators gave patients with KD progressive aerobic cycling exercise and gradually increased the amount of exercise over 12 weeks. The results showed that after 12 weeks, patients gained improvement in maximal exercise capacity, but not in maximal oxygen uptake and ADL scores. There are two clinical studies currently registered and underway, one giving patients high-intensity training; the other is a randomized double-blind placebo-controlled phase I/II clinical study code-named BVS857 (Novartis). The difficulty of KD clinical studies lies in its small number of patients and the lack of biomarkers that are specific and sensitive to the changes of the disease. On the other hand, the etiology of KD is clear and there are good disease models, and many potential treatments will emerge in the future as research into its pathogenesis progresses. Currently, the use of three-generation assisted reproduction technology can theoretically prevent female carriers from passing on abnormal genes to their offspring. The principle of this technology is to use single-cell genetic testing technology to select egg cells that do not carry the disease-causing gene, and to prevent the offspring from inheriting the disease-causing gene through in vitro fertilization and in vitro fertilization. Currently, our hospital has applied this world-advanced technology in clinical practice.