Abstract Details

Title Relapsing Myelopathy and Neuropathy in Adulthood: A Case of Biotinidase Deficiency

Topic General Neurology

Presentation(s) P5 - Poster Session 5 (8:00 AM-9:00 AM)

Poster/Presentation
Number 2-010

Objective

To discuss a case of biotinidase deficiency presenting with progressive and relapsing symptoms, including adult-onset cervical myelopathy and peripheral neuropathy.

Background

Inborn errors of metabolism represent an important differential diagnosis to consider in cases of progressive neurological decline. Although biotinidase deficiency has been reported to cause both peripheral nerve injury and myelopathy, adult presentations are rare. We present a case of progressive peripheral nerve injury and cervical myelopathy due to untreated biotinidase deficiency.

Design/Methods

Results

A 47-year-old female with biotinidase deficiency, diagnosed in infancy with hearing loss and imbalance, presented with progressive and episodic neurologic symptoms. Intermittent biotin supplementation preceded episodes of weakness and imbalance since with presentation in 2012. In 2021, she developed worsening lower extremity weakness and balance issues, with elevated creatine kinase and CSF protein levels. EMG showed possible demyelinating polyneuropathy. In 2024, after a viral illness, she experienced hand weakness progressing to torso and leg involvement. MRI revealed cervical myelitis, and serologic tests for NMOSD and MOGAD were negative. Three days of high-intensity steroids resolved her lower extremity symptoms.

On examination, she exhibited lower extremity hyporeflexia, lower extremity weakness, and multi-modality sensory loss with a positive Romberg sign. Repeat EMG confirmed severe polyneuropathy. She was advised to resume high-dose biotin supplementation. Biotinidase enzyme level at follow up was profoundly deficient with normal plasma acylcarnitine profile and urine organic acids, indicating she is now on appropriate supplementation.

Conclusions

This case highlights the relapsing-remitting neurological course of untreated biotinidase deficiency, which can affect the central and peripheral nervous systems. Common features of untreated biotinidase deficiency in children include seizures, hypotonia, ataxia, sensorineural hearing loss, and optic atrophy. Adults may present with disabling myelopathy and optic neuropathy, mimicking NMOSD. Neurologic injury can be prevented with proper biotin supplementation, making it crucial to consider biotinidase deficiency in cases of CNS and PNS decline.

Authors/Disclosures
Drew Weber, MD (University of Utah) PRESENTER	Dr. Weber has nothing to disclose.
Kyle Mahoney, MD (Johns Hopkins University)	The institution of Dr. Mahoney has received research support from Viela Bio.
Ashley Andrews, NP	Ms. Andrews has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Zevra Therapeutics . Ms. Andrews has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Amgen.
Paul D. Crane, MD (University of Colorado)	Dr. Crane has nothing to disclose.

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