In the early 1990s, units which followed the BPSU methodology were developed in Australia, Germany, the Netherlands, Switzerland and Malaysia. There are now units in 13 countries worldwide.
INoPSU was launched in 1998 at a meeting in Canada of the ten founding national units. The first INoPSU conference was held in Ottawa in 2000 and is now held every two years.
Since its conception, 10,000 clinicians covering a child population of 50 million have helped investigate over 200 rare conditions.