我在四川省纳溪县发现一女小学生,其指甲和趾甲呈圆锥状爪(见右图),爪与指中轴成30°—45°角。由于爪不断伸长影响小孩的行动,已多次修剪。初次修剪时发现其尖端稍空,似鸟类的羽轴状,再往下剪就有疼痛感,并有血液渗出,因而每指末端存有1—2cm圆柱状突起。修剪后新增生的角质能将前端的孔封闭,坚硬如牛角,再次修剪时需在热水中浸泡1—2小时方可将前端削去少量。指爪影响日常活动,趾爪影响着鞋,故该女孩的行动不如正常人方便。对该女孩的家族进行四代谱系调查,未见有相同性状的个体。其母及祖母在该女孩下地后几天即注意到 I discovered a schoolgirl in Naxi County, Sichuan Province. Her nails and toenails had a conical claw (see the figure on the right). The claws were at an angle of 30° to 45° with the axis of the finger. The claws have been pruned many times because the claws constantly affect the children’s actions. At the time of initial trimming, the tip was found to be slightly empty, resembling the bird’s plume, with a painful sensation of shearing down and blood oozing out, so that there was a 1-2 cm cylindrical protrusion at the end of each finger. After the pruning, the newly added raw keratin can close the hole in the front end and be firm as a horn. When pruning again, it needs to be immersed in hot water for 1-2 hours to cut away the front end. Fingers affect daily activities and claws affect shoes, so the girl’s actions are not as convenient as normal ones. A four-generation pedigree survey was conducted on the girl’s family and no individuals with the same traits were found. The mother and her grandmother noticed a few days after the girl went to the ground