In the 1970's, the government began to take steps for the treatment of congenital diseases. Mass newborn screening was started in October 1977 throughout Japan in order to detect five inborn errors of metabolism including phenylketonuria, maple syrup urine disease, homocystinuria, histidinemia, and galactosemia. In 1979, mass screening for congenital hypothyroidism was added to the original program. In 1989, screening for congenital adrenal hyperplasia was added and in 1992, screening of histidinemia was discontinued. Currently, screening covers six diseases. The government paid half the cost of screening tests initially and in 2001 this was raised to the full cost (approximately 3000 yen). Parents pay for sample collection. The program is carried out according to law. A new activity involving screening for Wilson disease now necessitates taking dried blood specimens from children 1-3 years old.