Yes Inclusion of a child with special needs in mainstream education is not always possible and in extreme cases a child may be given exemption from compulsory schooling. Alternatively, perhaps due to illness or repeated periods of hospitalisation, a child may be taught at home. However, in many cases education is provided by a specialist school. https://www.angloinfo.com/how-to/belgium/family/schooling-education/special-needs-education
In Wallonia: http://www.enseignement.be/index.php?page=0&navi=16
In Flanders: https://webgate.ec.europa.eu/fpfis/mwikis/eurydice/index.php/Belgium-Flemish-Community:Overview