遺伝カウンセリングにより患者の不安が軽減された網膜色素変性の2症例

Genetic counseling was useful in two cases of retinitis pigmentosa

要約　目的：遺伝カウンセリングにより網膜色素変性の不安が軽減した2症例の報告。

症例：1例は54歳女性で，幼少時から夜盲があり，35歳頃に網膜色素変性と診断された。現在の矯正視力は右0.7，左0.09で，両眼に求心性視野狭窄と典型的な眼底病変がある。両親が血族結婚であり，常染色体劣性遺伝と推定された。他の1例は52歳女性で，44歳頃に視野狭窄を自覚し，網膜色素変性と診断された。現在の視力は左右眼とも0.1である。母と妹に網膜色素変性があり，表現度の低い常染色体優性遺伝と推定された。

経過：第1例は患者の娘と孫，第2例は長女の子に網膜色素変性が発症する可能性を心配していた。両症例とも，娘はすでに成人であり，自覚症状がないので，孫の世代に発症する可能性が小さいことを説明し，本人の不安が軽減された。

結論：遺伝カウンセリングにより，網膜色素変性患者の子孫に発症する危惧が軽減され，心理的サポートとして有用であった。

Abstract　Purpose: To report two cases of retinitis pigmentosa（RP）in whom anxiety was reduced by genetic counseling.

Cases: One was a 54-year-old female who had had night blindness since childhood. She had been diagnosed with RP at the age of 35 years. She had currently visual acuity of 0.7 right and 0.09 left. Her parents were cousins, suggesting autosomal recessive inheritance. The other was a 52-year-old female. She had noticed visual field contraction at the age of 44 years, leading to the diagnosis of RP. She had currently visual acuity of 0.1, presumably due to cataract.

Clinical Course: Both cases were anxious about the possibility of RP in children of her daughter. In both cases, their daughters were found free of RP. The genetic counselor told them that the likelihood of passing on the disease to the descendants is similar to other families without RP.

Conclusion: Genetic counseling was useful in offering mental support to patients of RP by explaining the mode of inheritance of the disease.