Diagnostic Analyses of Retinal Dystrophy Genes: Current Status and Perspective

[Inherited retinal diseases in Germany-Challenges in health care supply structure and diagnostics]

BACKGROUND

Inherited retinal diseases (IRD) are rare eye diseases and pose high diagnostic challenges. A care structure with few highly specialized centers in Germany, misdiagnosis due to the lack of molecular genetic testing, and a lack of a central registry lead to a lack of reliable information on the prevalence and distribution of IRDs in Germany.

METHODS

Based on clinical data from an ophthalmological center and molecular data from a genetic center as well as a nationwide health insurance data query, we estimated the prevalence of IRDs in Germany in addition to collecting information on their phenotypic and genotypic distribution.

RESULTS

The median travelling distance to the ophthalmological center was 60 km. The most frequent diagnoses were retinitis pigmentosa, macular dystrophy and general retinal dystrophy. Molecular genetic testing was performed in 87% of patients with clinical suspicion of IRD, with marked differences in frequencies among age cohorts. The molecular genetic detection rate in the genetic center was 51%. The prevalence of inherited retinal dystrophy in Germany determined by health insurance data retrieval was approximately 1:1150.

CONCLUSION

Many patients must travel long distances to visit specialized clinics for IRDs with access to genetic testing. To obtain more reliable numbers on the prevalence in Germany, routine molecular genetic testing, and a national registry for IRD detection are needed.

[Diagnosis of inherited retinal dystrophies. Relevance of molecular genetic testing from the patient's perspective]

BACKGROUND

The diagnostic process of inherited retinal dystrophies (IRD) is impeded by their low prevalence and the variability of the clinical presentations; however, for patients a valid diagnosis is vital for future planning and evaluating the potential of an appropriate early treatment to delay disease progression.

OBJECTIVE

Aim of the current study was to outline the patients' journeys until they receive the final diagnosis. This should help uncover diagnostic shortcomings and highlight potential for improvement with respect to the use of genetic diagnostic testing.

MATERIAL AND METHODS

Data were collected by questionnaires and an online survey conducted by the self-help association PRO RETINA Deutschland e. V. among patients with IRD. Data were analyzed by descriptive statistics.

RESULTS

From 15 March to 22 April 2021, 183 questionnaires were completed and 42 online interviews conducted. The surveyed population consisted of 48% female patients, mean age was 55 years and first symptoms occurred at a mean age of 22 years. On average about 14 years passed from first symptoms until final diagnosis. Only 66% of the patients reported that they had received at least 1 diagnostic genetic testing; less than half of the patients (47%) received genetic counseling. The huge majority of patients (85%) would be interested in gene therapy.

CONCLUSION

From the perspective of affected patients, a shortening of the time to diagnosis, the use of molecular genetic testing and the offer of genetic counseling are important to improve patient care for patients with IRD.