Baran R
Ann Dermatol Venereol. 1980 May;107(5):431-5.
Attention was drawn to congenital onychodysplasia of the index fingers (C.O.I.F.) by Iso, and later by Kikuchi who collected several cases. Micronychia, polyonychia, anonychia, hemionychrogryphosis and malalignment are the observed index finger defects. Five classical criteria were given to characterize the C.O.I.F. syndrome: 1 degree congenital, 2 degrees involvement of index fingers, 3 degrees variability in nail appearance, 4 degrees non-familial, non-hereditary, 5 degrees without bone and joint abnormalities. Alternative criteria are suggested for this syndrome. These are: 1 degree congenital, 2 degrees unilateral or bilateral index finger involvement, variability in nail appearance, 4 degrees possible hereditary involvement, 5 degrees frequent associated bone abnormalities.
Iso首次关注到食指先天性甲发育异常（C.O.I.F.），随后Kikuchi收集了多例相关病例。观察到的食指缺陷包括小指畸形、多指畸形、无甲畸形、甲弯曲过度和排列不齐。给出了五条经典标准来描述C.O.I.F.综合征：1. 先天性程度；2. 食指受累程度；3. 指甲外观的变异性；4. 非家族性、非遗传性；5. 无骨骼和关节异常。针对该综合征提出了其他标准。这些标准为：1. 先天性程度；2. 单侧或双侧食指受累、指甲外观变异性；4. 可能的遗传受累；5. 频繁伴发的骨骼异常。
