Inherited retinal diseases are a group of rare, heterogeneous eye disorders caused by gene mutations that result in degeneration of the retina. Malattia Leventinese, also known as familial drusen, dominant drusen, or Doyne honeycomb retinal dystrophy, was first described in patients living in the Levantine Valley in canton Ticino of southern Switzerland in 1925. Characteristic clinical findings include radial macular drusen, large confluent drusen, and juxtapapillary drusen. Especially early visual symptoms typically starting in the 3rd and 5th decades include reduced central vision, photophobia, and metamorphopsia. Pigmented paravenous retinochoroidal atrophy (PPRCA) is an uncommon disease characterized by perivenous aggregations of pigment clumps associated with peripapillary and radial zones of retinochoroidal atrophy that are distributed along the retinal veins. Patients are usually asymptomatic and the disease process is non-progressive or slow and subtly progressive. It is commonly bilateral and symmetric. The autosomal- dominant late-onset retinal degeneration (L-ORD), caused by C1QTNF5 gene mutations, shows typical retinal abnormalities that can extend beyond the macula, and patients can report night blindness in addition to central vision loss. Interestingly, L-ORD patients can have long anteriorly inserted lens zonules and loss of iris pigment.
Doyne honeycomb retinal dystrophy/malattia leventinese induced by EFEMP1 mutation in a Chinese family