Angie,
Contact Lori at info@albinism.org and she'll put you in contact with Donna Appeall who runs the HPS network. Donna also is the mother of a children with Albinism. Yes, the easy answer is you can get testing for HPS and they will give you all the informnation you need to where you have to send the blood because the little understanding I have for HPS is the blood as to be read under an electron microscope.There is link directly from the HPS Network at www.hpsnetwork.org explaining how the diagnosis of HPS works.
http://www.hpsnetwork.org/en/hps-information/diagnosing-hps
http://www.hpsnetwork.org/en/hps-information/characteristics
http://www.hpsnetwork.org/en/hps-information/standard-of-care
http://www.hpsnetwork.org/en/hps-information/what-is-hps
I hope this links are helpful.