349 - A Rare Case of Familial ALS in an African-American Female

Case Diagnosis: Familial Amyotrophic Lateral Sclerosis (fALS)

Case Description: A 46-year-old African-American female, a Navy Veteran, with a history of low back pain following a motor vehicle accident, status post microdiscectomy a few years ago, anxiety, presented for electrodiagnostic study for weakness in lower extremities (LE). Her symptoms started a year ago with right thigh tightness, tingling, twitching, and progressed to bilateral LE weakness, requiring a cane for ambulation, and experiencing frequent falls. Extensive investigations, including brain and spinal MRIs, blood tests, yielded no significant findings.

Her family history revealed possible ALS in her father (died at 64, two years before her symptoms) and paternal grandfather (age unknown).

During physical exam muscle fasciculations were observed, predominantly proximal LE weakness, atrophy in right quadriceps, bilateral hypothenar, thenar muscles and brisk upper extremity reflexes.

Electrodiagnostic study was suggestive of motor neuron disease (denervation in three extremities, with limited occipitofrontalis and thoracic paraspinals exam by pain, reduced CMAP amplitudes, normal sensory responses).

Discussions: The fALS diagnosis was confirmed through genetic testing and was linked to a rare SOD1 c.341T >C (p.Ile114Thr) pathogenic mutation. This is the first reported case, to our knowledge, of a young African-American female with fALS spanning three generations. Most ALS cases are sporadic, making up around 90%. SOD1 usually accounts for 10-20% of familial ALS cases.

Conclusions:




Familial ALS is rare and often leads to delayed diagnosis, especially in females. It took one year for our patient before diagnosis was established. This case highlights the importance of prompt electrodiagnostic studies for unexplained neurological deficits and emphasizes the significance of gathering comprehensive family medical histories. Early ALS recognition can enable timely intervention and support for patients and their families.