Abstract
Purpose: :
Many forms of macular dystrophies have been described:Stargardt's disease , dominant Stargardt like disease , Best disease , Carolina dystrophy, Bietti’s disease , and AMD linked to ABCA4, CFH, C2 and ARMS 2 mutation or risk alleles. We describe a consanguineous family with a 6 y-old girl with congenital nystagmus , low vision and novel congenital macular dystrophy with absence of macula or fovea and associated brain anomalies seen for genetic counseling
Methods: :
The family had a complete ophthalmologic, neurologic examination, ERG, VEP, OCT, retinal angiograms,EEG brain MRI, and molecular genetic testing,
Results: :
She was born at term from first cousin parents with nystagmus and prenatally diagnosed corpus callosum agenesis. Her distance visual acuity was 20/200 O.U. and near acuity of Parinaud 4. She had no photophobia, night blindness or obvious dyschromatopsia. Her fundus examination showed bilateral oval lesions of complete macular atrophy with normal vessels and optic papilla without pigmentary deposits . Angiography confirmed symetric macular atrophy with Normal autofluorescence . Electrophysiology showed normal ISCEV flash ERG , OP and dark adaptation while pattern VEP at 60° showed no response at right and a delayed left P100 wave; VEP response was absent at 30° & 15° compatible with macular bundle dysfunction . OCT examination showed complete macular agenesis with absent foveal pit with thinning of the retina and interruption of the photoreceptor layer . ETDRS Center Macular thickness was 102 um at right and 92 at left , ETDRS right macular volume was 4.65 mm3 and 4.32 mm3 at left. She is having learning difficulties in first grade due to the combination of her visual impairment and her spatial comprehension and memory encoding impairment but her EEG, intelligence, speech and comprehension are normal. ABCA4 mutation testing was negative as well as screening of 18 known ARRP genes.Parents have normal visual acuity, ERG, VEP and OCT and retinal angiographs and brain MRI . The mother is however reported as having a granit-like fundus appearance and the father shows small hyperintense parenchymal foci on T2 MRI .
Conclusions: :
This association of congenital developmental severe macular dystrophy with associated corpus callosum agenesis and hippocampi hypoplasia involves a putative developmental gene controlling macular development and midline crossing of brain fibers with apparently recessive inheritance
Keywords: macula/fovea • neuro-ophthalmology: diagnosis • genetics