Aiji Clinic was located in Shinjuku Ward, Tokyo. Established in 1994 as Japan's only medical institution specializing in Down syndrome, it had been operating for many years. The clinic provided health management and developmental guidance for children and young adults with Down syndrome. In addition to these specialized services, it offered genetic counseling, addressing consultations regarding genetic testing and diagnosis. For pregnant women, it provided pregnancy counseling, prenatal testing, and prenatal diagnosis consultations. It also conducted awareness campaigns to promote the correct understanding of maternal serum marker screening. As a member of DSMIG, an international specialist organization, the clinic exchanged information and provided world-class developmental guidance information. However, Aiji Clinic closed on July 1, 2025.