baby boy malakai suffers rare medical condition pallister killian syndrome .
malakai can not see , can not hear , struggles to breath and may never walk .
stacy maitai gave up everything to take care of her seven-month-old son .
mother-of-two has been forced to survive on $ 90 a week from centrelink .
can not receive further financial assistance as she is not australian citizen .
the single mother moved from new zealand to perth about four years ago .
a fundraising page has been set up to help the struggling family .