It's not only the elderly who develop disabilities. If you have a relative who is relatively young, but who suffers from a disability or impairment that makes him or her unable to take the U.S. citizenship (naturalization) test, do not assume that your relative will not be able to get a waiver of the exam requirements due to age.
However, unless your relative has a disability that very clearly affects cognitive abilities – such as Down syndrome – you should expect that U.S. Citizenship and Immigration Services (USCIS) will review your relative's request for a disability waiver more carefully than if your relative were elderly.
To increase the chances that USCIS will approve your relative's request for a disability waiver, your relative or his or her interpreter or attorney should work carefully with the doctor to make sure that USCIS Form N-648 is complete and clearly explains the nexus (i.e. connection) between your relative's disability or impairment and his or her inability to take the naturalization test. For more information on this, see "Working With Your Relative's Doctor to Complete USCIS Form N-648."
Also, it is not enough that your young relative's disability makes it very or extremely difficult for him or her to take the naturalization test. Instead, it must be clear from the information on the Form N-648 that your relative is “unable” to take the test. For more information, see "How the USCIS Interviewer Will Approve or Deny an N-648 Disability Waiver."
If your relative has an extreme developmental disability, he or she may be totally dependent on others to deal with “activities of daily living” such as cooking, cleaning, dressing, and hygiene. In that case, it is fine for the doctor to mention the effect of the disability or impairment on your relative's ability to complete activities of daily living.
But if your relative's disability or impairment does not prevent him or her from working or living alone, the doctor should not discuss in Form N-648 your relative's ability to deal with activities of daily living. Your relative's interpreter or attorney should also be prepared to point out to the immigration officer who interviews your relative that USCIS's disability waiver guidelines specifically state that the immigration officer should not identify activities that your relative is capable of completing and then deny the disability waiver request on that basis. Instead, the officer is supposed to focus on whether the Form N-648 is complete and whether the doctor who filled it out clearly explained the connection between your relative's disability and inability to take the test.
If the USCIS officer insists on asking questions about your relative's living situation and his or her ability to cook, clean, and shop unassisted, politely ask to speak to a supervisor. Then, explain to the supervisor that a USCIS disability waiver memoranda specifically states that the officer should not ask questions about activities of daily living, unless the doctor discussed such issues in Form N-648.