One gene mutation accounts for bulk of cases, study finds
TUESDAY, Feb. 17 (HealthDay News) -- About 20 percent of children with sensorineural hearing loss also have eye disorders, a new study has found.
Sensorineural hearing loss, caused by damage to the inner ear or to the nerves that link the ear to the brain, affects up to three of every 1,000 children, according to background information in the study. Half of all cases in children are due to genetics, and one gene, GJB2, accounts for a large proportion of sensorineural hearing loss in whites.
For the study, Dr. Arun Sharma, of the University of Washington, Seattle, and colleagues reviewed data on 226 children with sensorineural hearing loss. Of that group, 49 (21.7 percent) had eye disorders, including 23 (10.2 percent) with refractive errors such as nearsightedness, farsightedness and astigmatism, and 29 (12.8 percent) with non-refractive errors. The researchers also found that the cause of sensorineural hearing loss was syndromic -- meaning it was associated with other symptoms -- in 11 children (4.9 percent), and five (2.2 percent) had syndromes with related eye problems.
All of the children were offered genetic testing for mutations in the GJB2 gene. Of the 144 who had the screening, 27 (18.8 percent) had two mutated copies of the GJB2 gene, and one of the 27 (3.7 percent) had an eye disorder. No eye problems were found in the 11 children with a single mutated copy, but there were eye problems in 22 (20.8 percent) of the 106 children with no mutations.
"This is consistent with the impression that GJB2 mutations result in sensorineural hearing loss but not in additional anomalies or syndromes," the researchers wrote.
"A multidisciplinary approach is important in the evaluation and treatment of children with sensorineural hearing loss to ensure that their medical, education and social needs are met," the study concluded. "Ophthalmologic evaluation can be beneficial for patients by allowing ophthalmologists to diagnose (and possibly treat) co-existing disorders that affect vision and by helping otolaryngology to determine cause of sensorineural hearing loss."
The study was published in the February issue of the journal Archives of Otolaryngology -- Head & Neck Surgery.
The American Academy of Family Physicians has more about hearing loss in children.
-- Robert Preidt
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