The present invention provides nucleic acid and amino acid sequences of an ATP binding cassette transporter and mutated sequences thereof associated with macular degeneration. Methods of detecting agents that modify ATP-binding cassette transporter comprising combining purified ATP binding cassette transporter and at least one agent suspected of modifying the ATP binding cassette transporter an observing a change in at least one characteristic associated with ATP binding cassette transporter. Methods of detecting macular degeneration is also embodied by the present invention.