P304
   
 

Presentation of the Ciliopathy, Alstrom Syndrome, as a Primary Early Onset Childhood Retinal Dystrophy

1. Leo Sheck1,2
2. Rasha Al-Taie1,2
3. Diane Sharp2
4. Andrea Vincent1,2

¹Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland
²Department of Ophthalmology, Greenlane Clinical Centre, Auckland District Health Board

Purpose
To report a case of severe early onset rod-cone dystrophy with genetic diagnosis contributing to the final diagnosis of Alström syndrome (AS), and to discuss the phenotypic spectrum and overlap observed in the ciliopathies of Bardet-Biedl syndrome (BBS), AS and Leber congenital amaurosis (LCA).

Methods
A child referred to Ocular Genetics clinic in Auckland District Health Board with severe rod-cone dystrophy and presumed LCA underwent detailed clinical history, family history and examination including electrophysiology (ERG). Genetic testing of the proband's DNA was undertaken on the microarrays from Asper Ophthalmic, Estonia.

Results
A 5 year old child noted to have nystagmus at age of 3 months, and subsequently poor vision. He was initially diagnosed with achromatopsia at 18 months of age. ERG showed no cone function but some rod function. Clinical examination at age 5 demonstrated a visual acuity of 6/60, a refractive error of +6.5D and bilateral widespread retinal pigmentary changes, and repeat ERG showed no rod or cone function. Obesity and small external genitalia were noted. Genetic testing on the LCA microarray (version 8.0) showed no mutations, but compound heterozygous mutations in the ALMS1 gene were identified on the BBS microarray (version 5.0).

Conclusions
Detailed clinical and family history, ocular and systemic examinations, along with ERG and genetic testing are important in the diagnosis of all cases of early childhood retinal dystrophy. Phenotypic spectrum exists between BBS and AS, as both conditions result in impairment in ciliary function.


 
RANZCO