A lack of support from the education system is preventing the city's autistic children from realising their full potential, experts and lawmakers say as they mark World Autism Day today. About one per cent of the world's population is estimated to be on the autistic spectrum - meaning they suffer one of a series of complex brain disorders causing difficulty in social interaction and communication. Based on this international measure, some 70,000 Hongkongers are autistic - much higher than the government's estimate of about 3,800 - and educators and lawmakers say autistic pupils struggle in an education system that is far too rigid. As an example, Labour Party lawmaker Dr Fernando Cheung Chiu-hung cited liberal studies, a compulsory subject in the Diploma of Secondary Education. While 90 per cent of pupils passed the subject, the pass rate for pupils with special needs was 60 per cent. Autistic children might struggle with metaphors or interpreting graphs, which the subject required, he said. Party colleague Peter Cheung Kwok-che said few services were available to help autistic young adults integrate into society. Even pupils who attend schools better equipped to help them faced challenges on graduation. At the West Island School, about five per cent of students have special needs, and five specialised teachers work with them. But Tricia Charles, head of its learning centre for children with moderate learning difficulties, said there was a lack of suitable vocational programmes or programmes to give children with special needs a path to university - especially if they spoke English. Parents seeking help for younger children - such as speech therapy - also face frustration. The Social Welfare Department provides training for children with special needs aged up to six through NGOs and schools. But while the number of training places it offers increased from 5,884 in 2011 to 6,245 this year, the number of applicants on the waiting list rose from 5,518 to 6,738 in the same period. A further 832 places will be added in the coming financial year. And some organisations offering services for autistic children are having to cut back. The Rainbow Project Learning Centre, a charity set up to help autistic children from English-speaking backgrounds, used to provide therapy for 40 children but had to close its therapy service two years ago due to a lack of cash. After raising money through public donations, it was able to reopen the therapy service this year for 15 children. "The government is not keen to provide funding to organisations like us who cover only a specific type of special need," said Keith Lee Seng Hoe, project director of the organisation, which also offers schooling. Both the Education Bureau and the Social Welfare Department rejected its funding applications. An Education Bureau spokesman said the funding request was not rejected because it offered services specifically to autistic children but because it was registered as a private school offering a non-formal curriculum.