The research into retinal degenerative disorders (RDDs) in Southern Africa involves the identification of the gene defects causing inherited blindness. The current focus is on severe RDDs such as Leber Congenital Amaurosis, Usher Syndrome, autosomal recessive Retinitis Pigmentosa and Stargardt disease. Our research to date has led to the identification of the causative gene defects in many families with RDDs, as well as the identification of two novel genes - PRPC8 and CA4. Furthermore, our finding that the most prevalent genetic defects in the USA (and the UK) are present in our patient cohort at an almost insignificant incidence, indicates a novel gene pool for this group of disorders.

The identification of the specific mutation and understanding of its biology in every individual with an inherited form of a RDD in SA, should provide the basis for establishing a solid foundation for the management of families with these genetic eye conditions and eventually, for the possible future treatment thereof.

• View the Retina eNEWs 2011 Research Update
• View a list of publications on RDD research
• View the Research Update newsletter 2007 
• Research progress of the RDD project in South Africa from 1990 - 2006
• View the Retinal Degenerative Disorders Fact-sheet

Protocol for the genetic testing of RDDs

Informed consent has to be obtained from all individuals from whom DNA has been isolated and on whom mutation screening or linkage analysis has been undertaken. Once a genetic mutation has been identified and confirmed in a subject/family with a history of Retinal Degnerative Disorder (RDD), the delivery of results will be as follows:  

A Genetic Counsellor will contact the family (individual or principal family member) by telephone, followed by a   letter, informing them that the disease-causing mutation has been found in their family. Included with this letter will be the option to receive their detailed results. Their signature on a consent form will be required along with details of the clinician/ophthalmologist of their choice who they wish to have deliver their results to them. The patient thereby gives us consent to release their molecular diagnostic results to the clinician/ophthalmologist/genetic counsellor as stated on the form. 

 Professor Greenberg will contact the professional of the individual’s choice and send the results to her/him.  Attached to this will be a letter of recommendation regarding the delivery of the genetic test results, counsellor information for post-result follow-up, together with references, where applicable. Should there be any need to study additional family members, this will be discussed with the clinician and a course of action will be decided upon as to who makes the contact and what the family is told. 

 The individual or principal family member will be contacted by their managing clinician and personally given the genetic result. Thereafter, the family members who would like to receive their results need to contact this division or their doctor. A member of the genetics team will follow-up within a month of the sending the report to ascertain what has transpired.  A plan of action as to how the results are delivered and whether predictive counselling is required will depend on the nature of the results and also the decision of who else in the family will and should be told. This will be discussed with the individual and decided upon, in consultation with the clinician/counsellor.

The individual retains the right at all times to either receive or refuse the results.

 All costs involved in this process of informing subjects of their molecular results ought to be borne by the participants.

 All genetic information is regarded as strictly confidential. Only information relating to the potential genetic cause of the inherited RDD will be released to the individual concerned, personally. No other genetic information or family information produced by this study will be released to any one else, including other family members. At this stage, it needs to be stressed and understood that no additional treatments will be available as a result of these test results.

 Participants need to be informed that there is no financial compensation, commercial benefits or other rewards for participation in this programme. There may be no direct benefit as a participant other than the possible medical advances and greater understanding of the genetic condition in the family that may result if causative genes are found.

 Individuals will be informed and assured that only other qualified research investigators may study their DNA samples, if necessary, but only for the purpose of further investigations of genetic factors causing inherited retinal eye disease.

• Download the RDD DNA consent form, RDD courier form or the RDD confirmation of diagnosis form 

• For more information regarding blood collection and costs of gene tracking, please contact Professor Jacquie Greenberg  (Phone: 021- 4066299)