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1. History
2. Exam
3. Photos
4. Diagnosis
5. Teaching Points
6. Comments

Case 109 Teaching Points

Characteristics

• Congenital neurosensory hearing loss and retinitis pigmentosa
• Autosomal recessive
• Prevalence of Usher’s is 4.4/100,000 in the general population
• Most common syndromic cause of retinitis pigmentosa (6-10%)
• 50% of cases of patients are both deaf and blind

Classification

Type I Usher’s

• Profound congenital sensorineural hearing loss
• Speech impairment (pre-lingual deafness)
• Vestibular symptomsChildhood retinopathy

Type II Usher’s

• Congenital partial, non-progressive deafness
• No vestibular symptoms
• Late-onset retinopathy

Type III Usher’s

• Uncommon outside of Scandinavia
• Adult-onset progressive deafness
• Adult-onset retinitis pigmentosa
• Vestibular ataxia
• Hypermetropic astigmatism

Type IV Usher’s

• Congenital complete deafness
• Elevated phytanic acid levels
• Retinitis pigmentosa
• Mental retardation

Treatment

• Early detection is important
• Educational, vocational, and psychosocial counseling
• Genetic counseling
• Hearing aids and lip reading
• Sign language and tactile aids

References

Seeliger MW, Zrenner E, Apfelstedt-Sylla E, Jaissle GB. Identification of Usher syndrome subtypes by ERG implicit time. IOVS 2001;42:3066-3071.

Kremer H, van Wijk E, Marker T, Wolfrum U, Roepman R. Usher syndrome: molecular links of pathogenesis, proteins and pathways. Hum Mol Genet 2006;15:R262-270.