UCDs present differently, though consequences can be similar.
Regardless of age of presentation, all untreated patients with UCDs face the risk of severe neurological consequences and premature death.1,2 Discover the risks of “asymptomatic” UCDs below.
Ongoing nonspecific symptoms:
headaches, lethargy, confusion, behavioral abnormalities, vomiting, and loss of appetite1
Changes to executive function:
chronic ammonia elevations; MRI scans showed evidence of white matter damage3,4
Absence of clinical symptoms:
patient may remain undiagnosed or misdiagnosed until crisis (if any)1,4-6
Long-term risk of brain damage:
altered neurocognitive subdomains, including working memory, executive function, and attention3,4,7
Risk of fatality:
10% risk of fatality as a result of partial defect8
The effects of chronic hyperammonemia can appear subtle and nonspecific, which can conceal the progressive risks of UCDs.2,4,6 Learn the telltale signs of late-onset UCDs below.
Repeat hyperammonemic episodes:
multiple hospitalizations and potential cognitive damage2,10,11
Diminished executive function:
white matter damage likely due to hyperammonemic crises and daily fluctuations in ammonia3
Incidental events trigger hyperammonemia:
fluctuations caused by illness, stress, major life milestones, and noncompliance with treatment plan10,12,13
Onset of severe symptoms:
hyperammonemic crises may be the cause of cognitive dysfunction1,10,11
Over a lifetime, late-onset UCDs
present risks for morbidity and mortality.1,2,6,13
Early symptoms in affected neonates are nonspecific but can quickly progress to coma and death.2,10 Explore the identifying characteristics of early-onset UCDs below.
May appear normal at birth:
discharged after 2 days10
Nonspecific symptoms present at home:
lethargy, vomiting, and somnolence2,10
hyperammonemic crises experienced at 5 weeks of age, followed by delay in normal developmental milestones1,2,4,12
cerebral edema, lethargy, anorexia, hyper- or hypoventilation, hypothermia, seizures, neurologic posturing, and coma2,10
“I take my medicine and follow my diet, but I’m struggling with fatigue, which makes it hard for me to concentrate at school.”
If you hear something similar from your patient, it may be a clue her UCD is not adequately controlled—look for subtle signs and symptoms with the UCD Assessment Tool.1,14
Could you be missing important clues ?Download the tool