Cone-Rod Dystrophy with Hearing Loss

Clinical Characteristics
Ocular Features: 

Patients note reduced vision in brightly-lit environments with onset in early adulthood and progressive central vision loss thereafter.   Nystagmus, photophobia, and dyschromatopsia may be present.  Younger individuals may complain of night blindness.  Visual fields show diffuse progressive suppression with relative sparing of selected areas such as the peripapillary region.  The ERG documents primary cone dystrophy but less involvement of the rods.  EOG testing in 4 patients showed reduced light-dark ratios.  Macular degeneration, attenuated vessels, subtle salt-and-pepper pigmentation, and spicular pigmentary deposits in the mid-periphery may be seen.

Systemic Features: 

The hearing loss is sensorineural in nature and can be progressive from its onset in childhood.

Genetics

This autosomal recessive disorder results from homozygous or compound heterozygous mutations in the CEPL78 (9q21.2) gene.

Treatment
Treatment Options: 

No treatment for the basic condition has been reported.  Assistive hearing devices and tinted lenses could be helpful.

References
Article Title: 

Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects

Nikopoulos K, Farinelli P, Giangreco B, Tsika C, Royer-Bertrand B, Mbefo MK, Bedoni N, Kjellstrom U, El Zaoui I, Di Gioia SA, Balzano S, Cisarova K, Messina A, Decembrini S, Plainis S, Blazaki SV, Khan MI, Micheal S, Boldt K, Ueffing M, Moulin AP, Cremers FP, Roepman R, Arsenijevic Y, Tsilimbaris MK, Andreasson S, Rivolta C. Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects. Am J Hum Genet. 2016 Sep 1;99(3):770-6.

PubMed ID: 
27588451

CEP78 is mutated in a distinct type of Usher syndrome

Fu Q, Xu M, Chen X, Sheng X, Yuan Z, Liu Y, Li H, Sun Z, Li H, Yang L, Wang K, Zhang F, Li Y, Zhao C, Sui R, Chen R. CEP78 is mutated in a distinct type of Usher syndrome. J Med Genet. 2016 Sep 14. pii: jmedgenet-2016-104166. doi: 10.1136/jmedgenet-2016-104166.

PubMed ID: 
27627988

References

Namburi P, Ratnapriya R, Khateb S, Lazar CH, Kinarty Y, Obolensky A, Erdinest I, Marks-Ohana D, Pras E, Ben-Yosef T, Newman H, Gross M, Swaroop A, Banin E, Sharon D. Bi-allelic Truncating Mutations in CEP78, Encoding Centrosomal Protein 78, Cause Cone-Rod Degeneration with Sensorineural Hearing Loss. Am J Hum Genet. 2016 Sep 1;99(3):777-84.

PubMedID: 27588452

Nikopoulos K, Farinelli P, Giangreco B, Tsika C, Royer-Bertrand B, Mbefo MK, Bedoni N, Kjellstrom U, El Zaoui I, Di Gioia SA, Balzano S, Cisarova K, Messina A, Decembrini S, Plainis S, Blazaki SV, Khan MI, Micheal S, Boldt K, Ueffing M, Moulin AP, Cremers FP, Roepman R, Arsenijevic Y, Tsilimbaris MK, Andreasson S, Rivolta C. Mutations in CEP78 Cause Cone-Rod Dystrophy and Hearing Loss Associated with Primary-Cilia Defects. Am J Hum Genet. 2016 Sep 1;99(3):770-6.

PubMedID: 27588451

Fu Q, Xu M, Chen X, Sheng X, Yuan Z, Liu Y, Li H, Sun Z, Li H, Yang L, Wang K, Zhang F, Li Y, Zhao C, Sui R, Chen R. CEP78 is mutated in a distinct type of Usher syndrome. J Med Genet. 2016 Sep 14. pii: jmedgenet-2016-104166. doi: 10.1136/jmedgenet-2016-104166.

PubMedID: 27627988