A groundbreaking study led by Dr Mridul Johari and Associate Professor Gina Ravenscroft, has identified that a genetic mutation is responsible for a rare and debilitating form of congenital myopathy.
The researchers uncovered that loss-of-function variants in the JPH1 gene are the cause of this disorder, which primarily affects the facial and eye muscles.
“The JPH1 gene produces junctophilin-1, a protein that helps form connections between different parts of muscle cells called triad junctions, allowing them to work properly. These connections are crucial for muscle function.”
Disruptions in these junctions impair excitation-contraction coupling and disturb calcium regulation within the muscles, leading to the severe muscle weakness observed in affected individuals.
The study examined four unrelated individuals—one from Australia, two from Europe, and one from the Middle East—who had experienced significant muscle weakness since birth.
Notably, their symptoms included drooping eyelids (ptosis) and paralysis of eye muscles (ophthalmoplegia). Researchers identified protein-truncating variants in the JPH1 gene as the likely genetic culprit.
Dr Johari, the study’s lead author, highlighted the significance of these findings.
“Our research has uncovered mutations in the JPH1 gene that were not previously linked to skeletal muscle disorders,” Dr Johari said.
“This discovery broadens our understanding of the genetic causes of congenital myopathy and underscores the crucial role of junctophilin-1 in muscle function.”
This research offers new hope for families grappling with unexplained muscle weakness and highlights the importance of early genetic diagnosis.
It also lays the groundwork for future research into potential treatments, offering hope to those impacted by this debilitating condition.
The findings have been accepted for publication in the Journal of Medical Genetics.
