These isolated populations have higher incidence of genetic diseases. From the Wikipedia page you cited:
There are instances of health problems attributed to endogamy, including glaucoma. In addition, there is a very high (42%) incidence of asthma among the population, and research by Noe Zamel of the University of Toronto has led to discoveries about the genetic nature of the disease. Three of the original settlers of the island had asthma.
There are instances of health problems attributed to endogamy, including glaucoma. In addition, there is a very high (42%) incidence of asthma among the population, and research by Noe Zamel of the University of Toronto has led to discoveries about the genetic nature of the disease. Three of the original settlers of the island had asthma.