Concurrent Phenylalanine Hydroxylase–Related Disorder and Celiac: A Rare Co-occurrence With Implications for Clinical Management

Comorbid nutritional disorders can present with clinical management challenges. Phenylalanine hydroxylase (PAH) deficiency and celiac disease are both associated with dietary protein intolerance, yet they are different disorders. Phenylalanine hydroxylase deficiency is a rare genetic disorder that results in elevated levels of phenylalanine (Phe) in the blood. It causes multisystemic abnormalities, including neurologic findings, seizures, episodic tremor, ataxia, and cognitive and sensory disturbances. In contrast, celiac disease is a common nutritional disorder that arises from immune-mediated enteropathy against dietary gluten. Herein, we describe the clinical findings in an adult with PAH deficiency and celiac disease to showcase some opportunities for improved personalized nutritional management.