About 1,600 people with Down Syndrome live in Croatia, and the Zagreb Down Syndrome Association gathers 150 of them and they are involved in various therapeutic activities.
The concert was attended by many citizens and public figures, and many of them wore mismatched socks to emphasise that diversity enriches society.
President Kolinda Grabar-Kitarovic also came to express her support. "I very much care that every child has the right to their childhood, to full inclusion in social and all other aspects of life, that we consider all persons with developmental difficulties or with disabilities as our equals and fully include them in everyday life," she said.
"We want all citizens to appreciate the difference of our children and our wards, and we want one day to get a large centre in Zagreb where all these children will have speech therapy and psychological support and a chance to advance," the vice-president of the Zagreb Down Syndrome Association, Danijela Zuanovic, told Hina.
Citizens were invited to donate funds for the establishment of such a centre by dialling the humanitarian phone number 060 92 00.
The event was held under the auspices of the City of Zagreb, the President of the Republic, Zagreb County and the Ministry of Social Policy and Youth, and was sponsored by the INA oil company.
World Down Syndrome Day is observed on March 21. The date, the 21st day of the 3rd month, was selected to signify the uniqueness of the triplication (trisomy) of the 21st chromosome which causes Down Syndrome.