1歳時発症で，同一の表現型を呈したhereditary motor and sensory neuropathy with spastic paraplegia（HMSN V型）の母子（母親と2女児）例

A Family of Hereditary Motor and Sensory Neuropathy with Spastic Paraplegia (HMSN type V) Presenting with Phenotypic Uniformity Including Onset in Early Childhood

　症例は38歳の母親，14歳の長女と11歳の次女。母親は1歳時の歩行開始直後から歩行異常を呈し，20歳代から小手筋の筋力低下と筋萎縮が進行。上下肢遠位筋の筋力低下と筋萎縮，上肢の腱反射低下と膝蓋腱反射の亢進，アキレス腱反射の低下，バビンスキー徴候，はさみ脚を伴う高度の痙性歩行，下肢遠位部の深部覚低下を認めた。軽度の伝導速度遅延と複合活動電位の振幅低下があり，腓腹神経生検で大径有髄線維の高度脱落，小型のonion-bulbの形成と再生線維を認めた。活動性の脱髄所見はなかった。娘2人も1歳時に歩行障害で発症，臨床像もほぼ母親と同様。発症様式から常染色体優性遺伝が疑われ，hereditary motor and sen-sory neuropathy with spastic paraplegia（HMSN type V）と診断した。本家系では，発症時期が1歳と早く，3例がほぼ同一の表現型を呈している点が特徴的である。

The proband was a 38-year-old mother, who had begun to walk abnormally at one year old. She devel-oped weakness and wasting in the intrinsic hand mus-cles in the third decades. On neurological examina-tions, she showed weakness with atrophy in the distal muscles of the upper and lower limbs, mild impair-ment of deep sensation in the feet, and severe spastic gait with scissoring. Deep tendon reflexes were hy-poactive in the arms and at the ankles, and brisk at the knees . Babinski sign was present bilaterally.