Line 318 of the Canada Tax Federal Worksheet concerns any amounts you can claim for dependants who are eligible for disability payments (Disability Tax Credit).
To claim for this your dependant must have been resident in Canada at any time in the previous year, and was dependant on you for their basic needs (food, clothing etc.)
Also, one of the following situations has to apply:
An amount was claimed on line 305 for the dependant,
An amount was claimed on line 306 or line 315 and the dependant was your, your spouse's or common-law partner's parent, grandparent, child, grandchild, brother, sister, aunt, uncle, niece, or nephew. (or you could have claimed if the dependant no income and been at least 18 years old in the previous year)
Complete the tax table calculator below to see what amount you may be able to claim