Hypercholesterolemia Successfully Treated With Two Different PCSK9 Inhibitors in a Patient With Glycogen Storage...

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Hyperlipidemia management in patients with neuromuscular disorders (NMD) lacks clear guidelines.
• Statin therapy can unmask underlying conditions like glycogen storage disease (GSD).

Purpose of the Study:

• To describe a novel use of proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors in a patient with GSD.
• To highlight the importance of inquiring about prior muscle symptoms before statin initiation.

Main Methods:

• Case report of a 46-year-old man with hyperlipidemia on simvastatin experiencing muscle symptoms.
• Diagnostic workup included muscle biopsy, electromyography/nerve conduction velocity, and whole-exome sequencing.
• Patient was treated with PCSK9 inhibitors (evolucumab, then alirocumab).

Main Results:

• Whole-exome sequencing revealed a pathogenic variant in the PHKA1 gene, diagnosing GSD IXd.
• The patient tolerated PCSK9 inhibitors, with only two prior reported cases of GSD treated with alirocumab.
• A literature review identified limited data on GSD management.

Conclusions:

• Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors may offer a therapeutic option for hyperlipidemia in patients with statin-intolerant GSD IXd.
• Proactive assessment for muscle symptoms and baseline creatine phosphokinase (CPK) is recommended before statin therapy.
• Further research is needed to establish optimal hyperlipidemia management strategies for patients with NMD, including GSD.