Hi there,
Before you read the below, remember, ultimately you should really do what you personally feel comfortable with!
That being said, culture is very important to consider here.
I have a candidate in the US who is not only disclosing their status, but actively mentioning it in both their Cover Letter and their "Why X Company" answer. In this case, I actually believe it will help this candidate given many Western countries are actively seeking out a diverse workforce.
I would also encourage this in Europe and Australia/NZ.
I would probably recommend not disclosing it in the ME. I am not sure about Singapore to be honest but I would guess they are somewhere in the middle.