There is not now and never has been in the history of Earth a Christian named 'Hussein'. The original Hussain was the grandson of the Prophet Muhammad. Any Christian calling himself Hussein would likely be killed by some nutcase Islamist, for insulting Islam.
The fact that they allowed Obama to call himself 'Hussein' is because they know he is a Muslim. And they do. America is the only country on Earth to deny that Barack (Arabic word for blessed) Hussein (relative of Muhammad) Obama (a Muslim tribal name in Kenya) is Islamic. In fact, an Egyptian newspaper published an article about Obama's ties to the Muslim Brotherhood, which is declared a terrorist group in many countries, including Islamic countries.