Increased life expectancy in people with untreated phenylketonuria.
Adults with untreated PKU and ID can live into their 70s, so design long-term supports.
01Research in Context
What this study did
The team tracked 17 adults with untreated PKU and intellectual disability.
All lived in the same residential center.
Six had died at an average age of 56. The 11 survivors averaged 56 years old.
What they found
People with untreated PKU and ID can live into their 70s.
This is much longer than doctors once thought.
The data came from one center, but the pattern is clear.
How this fits with other research
Ghaziuddin (1997) used the same case-series method to chart dementia in older adults with ID. Both studies show that ageing adults with ID need long-term planning.
Morad et al. (2007) and McQuaid et al. (2024) looked at constipation and gallstones in residential adults with ID. These papers add common health risks you should watch for as clients age.
McCarron et al. (2022) kept a large share of adults with ID in a study for 11 years. Their success proves you can track ageing clients over decades, just like Macdonall (1998) did.
Why it matters
Plan for decades of service, not just years. Update behavior plans, staff training, and estate planning as if your client will live to 75. Schedule annual health screens for common issues like hypertension and constipation.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add a yearly review date to every adult client’s behavior plan to update goals for ageing.
02At a glance
03Original abstract
The records of 17 people with intellectual disability and untreated phenylketonuria (12 females and five males), who were resident in the Stoke Park Group of Hospitals, Bristol, England, 25 years ago, were re-examined for life expectancy. Six subjects had died (five females and one male). The oldest deceased female was 69 years of age. The average age at death was 55.8 years. Eleven subjects were still alive (seven females and four males). The oldest living male was 79 years of age. The average age of the survivors was 55.7 years.
Journal of intellectual disability research : JIDR, 1998 · doi:10.1046/j.1365-2788.1998.00067.x