[Multicentric carpotarsal osteolysis in a rheumatologist's practice]

Area of Science:

• Genetics and Skeletal Dysplasias
• Rare Diseases
• Molecular Biology

Background:

• Multicentric carpotarsal osteolysis (MCTO) syndrome is a rare genetic skeletal dysplasia.
• It is characterized by aggressive osteolysis of carpal and tarsal bones, nephropathy, and craniofacial anomalies.
• MCTO is caused by missense mutations in the MAFB gene.

Observation:

• MCTO diagnosis is often delayed due to overlapping symptoms with childhood inflammatory joint diseases.
• This can lead to inappropriate long-term immunosuppressive therapy.
• A familial case of MCTO involving a mother and daughter is presented.

Findings:

• The described familial case of MCTO presented without kidney compromise.
• This challenges the typical presentation of progressive nephropathy in MCTO syndrome.
• The MAFB gene mutation's role in varied phenotypic expression is further supported.

Implications:

• Early and accurate diagnosis of MCTO is crucial to avoid unnecessary treatments.
• Recognizing non-classic presentations, like the absence of nephropathy, is important for diagnosis.
• Further research into MAFB gene mutations can elucidate the variable expressivity of MCTO syndrome.