Autoomal dominant inheritance of a negative electroretinogram phenotype in three generation

PURPOE: We report an abnormal electroretinogram with a negative configuration in a child who preented with moderate myopia, nytagmu, and viual developmental delay. We invetigated the electroretinogram and explored the poibility of a metabotropic glutamate receptor ubtype 6 mutation in ix family member panning four generation. METHOD: Cae report and family tudy: Complete eye examination and Ganzfeld electroretinogram were recorded from the maternal great-grandmother, maternal grandmother, mother, uncle, and ibling of the 7-month-old female proband. The electroretinogram wa repeated in the proband at 17 month of age. Dark adaptometry wa performed in all adult ubject. Fundu photograph and viual field examination were adminitered to the grandmother and mother. The metabotropic glutamate receptor ubtype 6 gene wa amplified and equenced in all affected ubject. REULT: The proband had a negative electroretinogram and a normal fundu. The maternal grandmother, uncle, and mother had an abnormal electroretinogram identical to the proband yet had no viual complaint. The ophthalmology examination in the adult ubject were normal, and ubequent examination of the proband at 17 month, 5 year, and 6.5 year of age howed no change in the fundu or refractive error. Her nytagmu reolved by 5 year of age. Rod threhold and viual field were normal in the affected adult ubject. No mutation in the metabotropic glutamate receptor ubtype 6 gene wa found. CONCLUION: In thi family, a negative electroretinogram wa not aociated with decreaed rod threhold, viual acuity lo, viual field lo, mucle dieae, or metabotropic glutamate receptor ubtype 6 mutation. Additional tudy will be required to undertand the nature of the negative electroretinogram phenotype in thi family.