I don't really think there is such a thing as "lifetime child support". However, if you look in the Family Code, under the 4100 series, or in that set of numbers, you will find a code section called "Support for Incapacitated Adult Child", and that will give you all your rights to ask for continued child support for "an adult child" who is disabled, or otherwise considered a dependent adult. If you are that child's caregiver, forever (it is possible), then you can ask for child support - but the Court most likely will sway away from calling it "lifetime child support" per se.
Child support is not typically a "life time" payment or jurisdiction issue within the courts. However, I agree with the counsel below that the Family Code does make provisions for special circumstances and cases where there are factors that may impact support of a child beyond the standard limitations.