Retinal dystrophies and differential diagnosis [476 genes]

Hereditary fundus dystrophies are a large group of disorders that generally affect the retinal pigment epithelium and photoreceptors, as well as frequently the choriocapillaris membrane. The clinical variability within this set of disorders is very great. Thus, hereditary retinal dystrophies can appear in isolation or accompany other extraocular clinical signs. They can debut at birth or do so in later stages, even once old age has arrived. Some affect the entire retina while others only affect specific regions of it, several have a rapidly progressive course, others a non-progressive one…

Under this non-specific heading, multiple entities are included, all of which are rare in the population, among which retinitis pigmentosa is the most prominent (the prevalence of the latter in Europe is estimated at one in every 3,500-4,000 people). Although each of them are rare entities, fundus diseases are generally the third most recurrent group of low-prevalence pathologies according to the Spanish registry of rare diseases.

The Retinal dystrophies and differential diagnosis service is the broadest targeted panel that we offer for this group of pathologies. It is indicated when there is a high suspicion of having retinal dystrophy in the patient and there is a certain degree of suspicion of a genetic origin of the same, but it has not been possible, based on the clinical data, to make a specific diagnosis.

This service is very useful in this context, by considering all the genes related to this group of disorders and even others associated with diseases that may cause difficulties during differential diagnosis.

On many occasions, the clinical patterns observed in the fundus differential diagnosis intermingle, generating serious difficulties, that´s why we consider a broad approach to be more clinically useful when these arise. The analysis of several hundred genes is intended to increase diagnostic sensitivity once the main phenotype has been defined; retinal dystrophy in this case.

A positive result confirms the clinical diagnosis and serves to convey prognostic information. In certain cases, in patients with hereditary retinal dystrophy and some specific mutations, we may recommend a drug based on gene therapy.

Service indicated when after evaluation by an expert ophthalmologist, there is a high suspicion of hereditary retinal dystrophy, not being possible to make a specific diagnosis based on clinical data.