Congenital Anomalies in Ancient Japan as Deciphered in the Nihon shoki (Chronicles of Japan)

Tojima and Yamada 26 associated with fatality have also been reported in medical journals.However, the number of cases caused by postnatal disease or by accidents is generally much larger than those possibly caused by the prenatal situation.Thus, it was difficult to grasp the epidemiological status of congenital anomalies even after the 1800s.For this reason, it has been challenging to elucidate the actual situation of congenital anomalies before the spread of modern medical science.This study, however, demonstrates the potential of historical documents to help us in understanding the epidemiology of congenital anomalies in ancient times, using Japan as an example.As in other countries, systematic study of human congenital anomalies in Japan started in the 1960s, and modern medical journals began to be published only in the late 1870s.Consequently, it was challenging to grasp the degree of incidence or the kinds of congenital abnormalities in pre-modern Japan.However, numerous ancient historical documents are preserved in Japan.Careful reading of these historical sources reveals several descriptions suggesting congenital morphological or functional abnormalities.The oldest official historical chronicle that survives in Japan is the Nihon shoki 日本書紀, which is said to have been completed in 720.It is a chronological text whose compilation was ordered by the emperor (tennō 天皇)-the world's longest-running imperial family.The Nihon shoki consists of a mythological part as well as a record of the genealogy and achievements of forty-one generations of emperors, from the first emperor, Jinmu 神武, to Emperor Jitō 持統.It is written in Literary Sinitic and in annalistic style, with years and dates during each emperor's reign being recorded according to the Chinese sexagenary calendrical cycle.The Nihon shoki is considered to contain more legendary elements than the five subsequent official national histories.In particular, post-World War II historiography tended to reject pre-war studies and thought, and several historians proposed theories questioning the historicity of all accounts in the Nihon shoki.However, recent archaeological excavations of the ancient capital and research on wooden documents called mokkan 木簡 have shown that the descriptions in the Nihon shoki (not the entirety but a part of its descriptions at least) accurately reflect what actually happened. 3 The existence of the emperors mentioned in this document has been proven by the archaeological record as well.An inscription on an iron sword excavated from the Inariyama 稲荷山 burial mound in 1968, for example, proves the existence of the twenty-first emperor, Yūryaku 雄略, 4 which means that the Nihon shoki is not a work of fiction but a chronicle of actual events.Many descriptions in this document, especially those recounting events after the seventh century, have been verified by the findings of such archaeological excavations.