[Inclusion body myopathy with Paget's disease of bone and frontotemporal dementia]

Area of Science:

• Genetics
• Neurology
• Pathology

Background:

• Inclusion body myopathy with Paget's disease of bone and frontotemporal dementia (IBMPFD) is an autosomal dominant disorder.
• Mutations in the VCP gene cause IBMPFD, affecting the valosin-containing protein (VCP) involved in cellular processes.
• VCP plays critical roles in protein quality control, protein aggregation, mitochondrial function, and cell proliferation.

Purpose of the Study:

• To summarize the clinical and pathological features of IBMPFD.
• To highlight the diagnostic challenges associated with this rare disease.

Main Methods:

• Review of clinical data and pathological findings in patients with IBMPFD.
• Analysis of the role of VCP gene mutations in disease pathogenesis.

Main Results:

• Muscle weakness is the most common symptom, with onset around age 40.
• Pathology reveals cytoplasmic/nuclear inclusions, rimmed vacuoles, and myofibrillar disorganization.
• Paget's disease of bone affects about half of patients, while frontotemporal dementia occurs in one-third, typically later.

Conclusions:

• IBMPFD is caused by VCP gene mutations and presents with a spectrum of symptoms including myopathy, bone disease, and dementia.
• The disease is not as rare as previously thought, but its varied presentation complicates diagnosis.
• Recognizing the diverse clinical manifestations is crucial for accurate and timely diagnosis.