Form 428 for your province or territory of residence needs to be completed to determine your provincial or territory tax. It contains a variety of tax credits you may claim (including Disability Transfer Amount, Basic Personal Amount, etc.).
Please see this article on the CRA website about Form 428 for more information: http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns409-485/428-eng.html
A guide to disability tax credit may help you to understand better. Please check this website for details:
https://turbotax.intuit.ca/tips/a-guide-to-the-disability-tax-credit-5294