Issues for consideration in dihydropteridine reductase (DHPR) deficiency: a variant form of hyperphenylalaninaemia.

Doctors wrote up one adult with DHPR deficiency. This is a rare metabolic problem that can look like autism plus severe ID. The team tracked what happened after medical care stopped at age nine and then restarted at thirty.

When treatment stopped, the client’s movement and mood got worse year after year. Restarting the same low-cost drug at age thirty brought quick gains in alertness and walking. The case shows lost skills can return even decades later.

Kovačič et al. (2020) and Sutton et al. (2022) show adults with ID use the ER often and are admitted four times more than typical patients. Their data say ‘watch this group closely.’ Branford (1997) gives the action step: re-check rare metabolic causes when skills slide.

Nuebling et al. (2024) found HIV testing in adults with IDD is under one percent. Together these papers paint the same picture: serious, treatable conditions are missed in adults with ID.

Martin et al. (1997) list high rates of vision, hearing, and dementia problems in residential settings. Add DHPR deficiency to that checklist if you see spasticity, drooling, or sudden behavior shifts.

You may serve adults whose challenging behavior or lost daily-living skills stem from an untreated inborn error. Ask the medical team to re-test for DHPR and other metabolic screens, even if prior labs were normal. A cheap pill could restore mobility and cut problem behavior within weeks.