Table 2 Phenotypes of hearing impaired carriers of SLC26A5 IVS2-2A>G.
Case | Type of Hearing Loss; Age at onset | Associated Anomalies | Family History | Ethnicity | GJB2 , GJB6, 12S rRNA |
|---|---|---|---|---|---|
1 | Profound sensorineural on right, severe conductive on left; Congenital | Internal auditory canal hypoplasia, hypoplastic vestibulocochlear nerve on right; External auditory canal atresia, malformed ossicles on left | None reported | Hispanic | Heterozygous GJB2 V27I polymorphism, no mutations or other variants found |
2 | Severe to profound on right, moderate to severe on left, mixed, progressive; Early childhood, sudden, with head trauma and ear infection | Bilateral enlarged vestibular aqueducts; Disequilibrium; History of ear infections and possible meningitis | None reported | Caucasian | No mutations or variants found |
3 | Moderate to severe, bilateral, sloping audiogram, sensorineural, progressive; Childhood to young adulthood | None | Consistent with autosomal dominant inheritance | Caucasian | No mutations or variants found |
4 | Moderate on right, mild to moderate on left, sensorineural, progressive; Childhood | None | Hearing impaired sibling (progressive, mild on right, mild to moderate on left, sensorineural; childhood onset; renal malformation); hearing impaired grandparent (unknown severity, possibly noise-induced) | Uncertain: Caucasian/Mixed Caucasian | No mutations or variants found |