From epidemiological investigations, it has been found that ankylosing spondylitis (AS) does have a clear tendency to develop in families. The development of AS and HLA-B27 (hereafter referred to as B27) have been shown to be closely related, with data showing that the prevalence of AS is 0.1% in the general population, 4% in the family line of AS patients, and up to 11%-25% in the first-degree relatives of B27-positive AS patients, suggesting an increased risk of AS in B27-positive individuals or those with a family history of AS. Literally, if your husband is a B27-positive AS patient, the likelihood of your child having the disease is between 11% and 25%. Of course, the likelihood of your child having the disease is also related to his or her gender, whether he or she is B27 positive, and the presence of other environmental and infectious factors.