“…At present, there is little epidemiological data on PG, and the literature shows that its incidence, age at onset, and sex preference differ, likely due to diagnostic difficulty and the lack of a gold diagnostic standard recognized by consensus. However, an analysis of the literature revealed that the incidence of PG is relatively low, the age distribution is wide [including infants, which account for approximately 4% of cases of PG and the elderly (11, 12)], and it has also been reported in pregnant women (13,14). Statistics published by British scholars showed that the incidence was 0.63/100,000 individuals, the sex difference was not significant (male vs. female = 41% vs. 59%), and the median age at onset was 59 years (15).…”