He has made seminal discoveries relating to the pathogenesis of retinoblastoma and retinitis pigmentosa and identified the mutant genes causing these conditions".
[6] In 2006 Dryja became the head of Translational Medicine in Ophthalmology at Novartis Institutes for Biomedical Research (NIBR) in Cambridge, Massachusetts.
[4] Dryja started his research career in 1981 by applying the fledgling field of human molecular genetics to the study of retinoblastoma, a cancer of the retina that arises in childhood.
As a recently trained ophthalmologist, he interacted with ophthalmic surgeons in the northeast USA to personally obtain blood and tumor samples from children with retinoblastoma who had eyes enucleated as part of their therapy.
This was compelling evidence for the recessive nature of tumor suppressor genes that was proposed by Alfred Knudson (the 2-hit hypothesis) decades earlier based on epidemiologic data.
The discovery of homozygosity of chromosome 13 was contemporaneously and independently discovered by Brenda Gallie, Rosaline Godbout, and Robert Phillips in Toronto and by Webster Cavenee and Ray White’s group in Salt Lake City, and the data was published in a set of co-authored papers in 1983 and 1984.
[10][11][12] Numerous tumor suppressor genes have since been identified and found to play a key role in most human cancers.
Dryja subsequently found a retinoblastoma that was homozygous for a deletion that encompassed an already cloned DNA segment with the arbitrary laboratory name H3-8.
[21] From the late 1980’s to the mid-2000’s, Dryja gradually shifted his research to focus on hereditary, blinding photoreceptor diseases such retinitis pigmentosa.
[26][27] Dryja also discovered patients with mutations causing a novel form of abnormal vision he named bradyopsia due to photoreceptors having a slow recovery after light exposure.