Fundus Albipunctatus: A Novel Mutation

Fadwa Al Adel, Irma Lopez, Ayesha Khan, Robert Koenekoop, Julie Racine and Ahmed Basheikh

Department of Ophthalmology, Princess Nourah bint Abdulrahman University, Saudi Arabia
Department of Ophthalmology, McGill University, Canada
Department of Ophthalmology, Eye Clinic, Nationwide Children's Hospital, United States
Department of Ophthalmology, King Abdulaziz University, Saudi Arabia

^*Correspondance to: Fadwa Al Adel 

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Abstract:

Background: The aim of this paper is to describe a patient with fundus albipunctatus from Africa who is developing a cone dystrophy with a new mutation in RDH5.Methods: A 24-year-old female from Burundi presented with difficulty to adapt to darkness after being in the light since the age of 9 years old. The clinical history, visual field, electroretinogram (ERG), dark adaptation test, spectral-domain optical coherence tomography (SD-OCT); fundus autofluorescence (FAF) and polymerase chain reaction (PCR) plus DNA analysis (by Sanger sequencing) were performed.Results: Fundus examination revealed scattered, homogenous, yellow-white dots throughout both fundi. OCT showed extrafoveal numerous well-demarcated homogenous dome-shaped lesions originating in the RPE. FAF showed a lack of autofluorescence (AF). Electroretinogram of the cone and the mixed rod-cone system had a normal morphology but with a significant decrease in the a and b wave amplitudes and a delayed peak time. The rod-mediated ERG was non-detectable. However, after a prolonged (3-hour) period of dark adaptation, the rod-mediated ERG was detectable and the b-wave reached 48% of normal value. The DNA analysis and sequencing of RDH5 revealed a homozygous c. 524-526delACT mutation, leading to a protein change of p.Tyr175del, which has not been reported before. The cone ERG results, strongly suggest that she is developing a cone dystrophy, despite the fact that she is asymptomatic and still maintains 20/20 vision and normal color discrimination.Conclusion: We identified a new deletion in RDH5 responsible for fundus albipunctatus with a progressive cone dystrophy; c. 524-526delACT in a patient from Burundi.

Keywords:

Fundus albipunctatus; RDH5; Cone dystrophy; 11-cis retinol dehydrogenase; Dark adaptation; Spectral-domain optical coherence tomography (SD-OCT); Fundus autofluorescence

Cite the Article:

Adel FA, Lopez I, Khan A, Koenekoop R, Racine J, Basheikh A. Fundus Albipunctatus: A Novel Mutation. Ann Clin Case Rep. 2016; 1: 1135.