What is the origin of petal-shaped nails?

In 2005, Bian Jianchao, an associate professor in the Epidemiology Research Office of School of Public Health, Fudan University, and Hao Weiguo, a graduate student, conducted a genetic investigation on the legend of Hongtong Tania. The results show that the distribution of petaloid nail is decreasing from Shanxi to Henan, Jiangsu and Zhejiang to Jiangxi and Fujian. This shows that the distribution of petaloid nails in a certain area is indeed related to Shanxi immigrants. Hao Weiguo and his party started from Shanxi, a western province, all the way to the southeast, passing through several provinces with the largest number of immigrants in Shanxi in history, and even Fujian Province, which has little relationship with Shanxi immigrants in historical records. Hao Weiguo and others conducted a field investigation on petaloid nails in a village in Shaanxi, Shanxi, Henan, Jiangsu, Zhejiang, Jiangxi and Fujian provinces. These villages are located in Hongdong County of Shanxi Province, zhouzhi county City of Shaanxi Province, Yuzhou City of Henan Province, Huai 'an City of Jiangsu Province, Huzhou City of Zhejiang Province, Yushan County of Jiangxi Province and Yongtai County of Fujian Province. At the same time, they also selected 10 microsatellite loci to analyze the genetic polymorphism of the investigated population. After comparing the genetic polymorphism of the investigated population with the regional distribution difference of petaloid nails, the following results were obtained: the frequency of petaloid nails in the seven provinces investigated was 79. 17% and 79.55% respectively. If the frequency of petaloid onychomycosis is divided into three grades: high, medium and low, Shanxi and Shaanxi provinces with frequency of 79. 17% and 79.5 1% are high frequency regions, Henan, Jiangsu and Zhejiang provinces with frequency of over 60% are medium frequency regions, and Jiangxi and Fujian provinces with frequency of 30% are listed. Among the petaloid nails investigated in these areas, 98.82% are divided into two petals, and 65,438+0.18% are divided into three petals. The petaloid nail in the investigated population has been genetically mutated for hundreds of years. Based on these investigations and statistical data, Hao Weiguo came to a phased and regional conclusion: "The frequency of petaloid nails is decreasing from Shanxi to southeast." Hao Weiguo's conclusion is consistent with the historical facts of immigrants, that is, in terms of immigrant areas, the farther southeast, the fewer immigrant areas.

Therefore, Hao Weiguo believes that "according to the immigration situation and folklore in Shanxi. We speculate that petal-shaped nails may have originated in Shanxi ... and spread all over the country with immigrants. The petaloid nail is indeed related to the distribution of immigrants, but is it a unique sexual feature of the Han people? With the deepening of the investigation, this conclusion has not been scientifically confirmed. Hao Weiguo's investigation area in Shanxi was selected in Hongdong County, Shanxi Province, the center of Tuoba family legend. In the village he investigated, 26 nuclear families and 1 complete it runs in the family families participated in the survey. The pedigree analysis of these families showed that the frequency of petaloid onychomycosis was 79.5 1%, of which 82.28% was male and 76. 15% was female. At the same time, some people have the sexual characteristics of petal-shaped nails on both feet, and some people have petal-shaped nails on one foot and normal little toenails on the other. In this study, Hao Weiguo investigated the youngest tarsal nail for 3 months, and the youngest petaloid nail appeared at 1 year. Some people are not born with repeated little toes, but do not appear until they are 5 years old.