Myopia and Deafness

Clinical Characteristics
Ocular Features: 

High myopia (6-11D) is usually diagnosed during infancy or in the first year of life.  Nine patients so far reported have ranged in age from 13 to 60 years if age.  Vitreoretinal degeneration has not been reported.

Systemic Features: 

Prelingual hearing loss has been identified in all patients, ranging in severity from moderate to severe.  No other neurological problems have been found.  CT scans of the temporal bone are normal.  No developmental delays or cognitive deficits have been identified.

Genetics

SLITRK family genes code for membrane proteins, expressed primarily in neural tissues. Mutations in SLITRK6 in the reported families cause loss of function.  In cultured cells from rodents the protein product impacts synapse induction and neurite modulation.  In Slitrk6 knockout mice, there is a reduction of cochlear innervations with reduced startle responses and impaired brainstem responses.  Axial length in these mice is normal at birth but adults have a significant increase in eye size.

Treatment
Treatment Options: 

The refractive error should be corrected and assistive hearing devices may be helpful.

References
Article Title: 

SLITRK6 mutations cause myopia and deafness in humans and mice

Tekin M, Chioza BA, Matsumoto Y, Diaz-Horta O, Cross HE, Duman D, Kokotas H, Moore-Barton HL, Sakoori K, Ota M, Odaka YS, Foster J 2nd, Cengiz FB, Tokgoz-Yilmaz S, Tekeli O, Grigoriadou M, Petersen MB, Sreekantan-Nair A, Gurtz K, Xia XJ, Pandya A, Patton MA, Young JI, Aruga J, Crosby AH. SLITRK6 mutations cause myopia and deafness in humans and mice. J Clin Invest. 2013 May 1;123(5):2094-102.

PubMed ID: 
23543054

References

Tekin M, Chioza BA, Matsumoto Y, Diaz-Horta O, Cross HE, Duman D, Kokotas H, Moore-Barton HL, Sakoori K, Ota M, Odaka YS, Foster J 2nd, Cengiz FB, Tokgoz-Yilmaz S, Tekeli O, Grigoriadou M, Petersen MB, Sreekantan-Nair A, Gurtz K, Xia XJ, Pandya A, Patton MA, Young JI, Aruga J, Crosby AH. SLITRK6 mutations cause myopia and deafness in humans and mice. J Clin Invest. 2013 May 1;123(5):2094-102.

PubMedID: 23543054