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Updated: Jun 29, 2025

Functional Characterization of Endogenously Expressed Human RYR1 Variants
Published on: June 9, 2021
PYROXD1-associated myopathy
Matthew Selwyn D'Costa1, Enrico Bugiardini2, Ashirwad Merve3
1Medicine, UCL, London, UK zchamdc@ucl.ac.uk.
Abstract:
PYROXD1-associated myopathy is a rare genetic form of limb-girdle muscular dystrophy (LGMD) with only 23 previous cases having been reported in the literature. The exact role of PYROXD1 in the pathophysiology of LGMD remains unclear. We describe two brothers who presented to the neuromuscular clinic with progressive weakness of their upper and lower limbs over the preceding decades. Our case highlights how recent advancements in genetic sequencing have revolutionised the diagnostic classification process for LGMD and provided opportunities to establish diagnoses for previously unclassified myopathies. We also illustrate how the increased adoption of muscle MRI to identify disease and target muscle biopsy can provide better quality and more informative samples for classification. Finally, our report details the clinical and histopathological findings found in both cases adding valuable data to the currently limited information published on PYROXD1-associated myopathy.
Insights
PYROXD1-associated myopathy, a rare limb-girdle muscular dystrophy, is detailed in two brothers. Advanced genetic sequencing and muscle MRI aided diagnosis, adding crucial data to this uncommon condition.
Area of Science:
- Neuromuscular Disorders
- Genetic Medicine
- Histopathology
Background:
- PYROXD1-associated myopathy is a rare limb-girdle muscular dystrophy (LGMD) with limited reported cases.
- The precise role of PYROXD1 in LGMD pathophysiology is not fully understood.
Observation:
- Two brothers presented with decades of progressive upper and lower limb weakness.
- Clinical presentation and histopathological findings were meticulously documented.
Findings:
- Recent genetic sequencing facilitated the diagnosis of this previously unclassified myopathy.
- Muscle MRI proved valuable in disease identification and guiding targeted muscle biopsy.
Implications:
- This case expands the understanding of PYROXD1-associated myopathy with detailed clinical and histopathological data.
- Advances in diagnostic technologies are crucial for classifying rare myopathies.
- Improved diagnostic approaches enhance the quality of samples for accurate classification.
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