First Genetically Proven Case Report from Saudi Arabia of Hereditary Transthyretin Amyloidosis Mimicking ALS
A 47-year-old man in Saudi Arabia arrived at a clinic with slowly worsening weakness on his right side, slurred speech, and visible muscle wasting. Over 18 months, his symptoms began to resemble amyotrophic lateral sclerosis (ALS), a neurodegenerative disease that destroys motor neurons and typically leads to progressive paralysis. Early tests seemed to confirm the suspicion.
But something didn’t fit.
The case is described in detail in the report titled “Hereditary transthyretin amyloidosis mimicking ALS: First genetically proven case report from Saudi Arabia,” authored by Hosna Elshony, Rakan Almuhanna, Khaled O. Albazli, and Rabia Muddassir.
Unlike classic ALS, the patient also showed subtle sensory loss in a glove-and-stocking pattern, an unusual feature for a disease that primarily affects movement. Reflexes were brisk, yet there was no spasticity. Even more puzzling, nerve conduction studies revealed damage to sensory nerves. ALS, by definition, should spare sensation.
Not every ALS-like syndrome is ALS
As clinicians analyzed further, additional anomalies emerged. Mild thickening of the heart muscle hinted at a systemic condition rather than a purely neurological one. Genetic testing eventually provided the crucial clue: a mutation in the TTR gene, confirming hereditary transthyretin amyloidosis (ATTRv). ATTRv is a rare inherited disorder in which misfolded transthyretin proteins accumulate as amyloid deposits in nerves and organs. While it usually presents with peripheral neuropathy and autonomic dysfunction, it can occasionally mimic motor neuron disease so closely that patients may be misdiagnosed as having ALS.
“Here, we report the first genetically confirmed case of hereditary ATTRv mimicking ALS in Saudi Arabia, highlighting key diagnostic pitfalls and emphasizing the importance of considering systemic and potentially treatable etiologies in patients presenting with atypical motor neuron syndromes.” Elshony et al.
In this case, the mimicry was striking, but misleading. Unlike ALS, ATTRv is treatable. New therapies, including TTR-stabilizing drugs and gene-silencing treatments, can slow or halt disease progression if started early.
The case, the first genetically confirmed ALS mimic of its kind reported in Saudi Arabia, highlights a growing message in neurology: not every ALS-like syndrome is ALS. “As the first genetically confirmed case of ATTRv mimicking ALS in Saudi Arabia, this report highlights the importance of considering hereditary amyloidosis in the differential diagnosis of motor neuron syndromes, especially in populations with high consanguinity and emerging genetic data. Early diagnosis enables access to disease-modifying therapies and transforms prognosis. ATTRv remains an essential and increasingly treatable consideration in neuromuscular medicine,” the authors concluded.
