Abstract
Purpose:
A series of 55 Patients with various eye anomalies were tested for Copy Number Variation using microarray analysis. A consanguineous family with syndromal retiniits pigmentosa associated with immune deficiency, hearing loss and leukodystrophy was included.
Methods:
Patients and family were studied using Illumina platform with HumanHap 300, HumanCytoSNP-12 microarray with 300K markers , Analysis software from Illumina, GenomeStudio 2010.3, and CNV partition 3.1.6 were used. Fluorescent in Situ Hybridisation was used to confirm the duplication using appropriate probes
Results:
This family with first cousin parents from north african origin had 3 of 4 sons affected with retinitis pigmentosa with low vision from infancy and scotopic ERG anomalies as well as hypogamma globulinemia requiring monthly gamma globulin infusions.The middle son proband also developed leukodystrophy on MRI as well as mild hearing loss while the youngest sister had only immune deficiency. A 2.5 Mb region on 12p13.33-p13.32 was duplicated in affected sibs including several genes associated with OMIM pathology entries. In particular TULP3 whose deletion was recently associated with glaucoma while its duplication may be involved in the ocular phenotype. TULP3 is a cliopathy gene associated with intraflagellar transport and has been shown to bridge IFT-A complex and membrane phosphoinositides to promote ciliary trafficking of G coupled receptors into primary cilia. TULP3 and IFT-A negatively regulate hedgehog signaling in the neural tube. The different genes possibly involved in other aspects of the phenotype will be discussed.
Conclusions:
Microarray analysis is a useful tool to assess patients with ocular anomalies particularly in syndromal association includiing in consanguineous families. Duplication of the TULP3 gene stands out as a possible candidate gene for RP while its deletion has been associated with glaucoma.
Keywords: 688 retina •
535 gene microarray •
612 neuro-ophthalmology: diagnosis