Novel ANKH amino terminus mutation (Pro5Ser) associated with early-onset calcium pyrophosphate disease with...

Area of Science:

• Genetics
• Rheumatology
• Biochemistry

Background:

• Calcium pyrophosphate disease (CPPD) is a metabolic arthropathy characterized by the deposition of calcium pyrophosphate dihydrate crystals in joints.
• Mutations in the ANKH gene, which encodes a pyrophosphate transporter, are associated with familial forms of CPPD.
• Early-onset and severe presentations of CPPD suggest a potential genetic etiology.

Observation:

• A 32-year-old woman presented with severe, childhood-onset arthropathy and chondrocalcinosis affecting multiple joints and the spine.
• Genetic analysis revealed three sequence variants in the ANKH gene, including a novel nonsynonymous mutation (c.13 C>T) in exon 1.
• This mutation, replacing proline with serine at codon 5, was also identified in the proband's father, who exhibited similar clinical manifestations.

Findings:

• A novel ANKH gene mutation (p.Pro5Ser) is associated with early-onset, severe calcium pyrophosphate disease (CPPD).
• The identified mutation in ANKH exon 1 demonstrates reduced pyrophosphate transport, contributing to crystal deposition.
• The familial inheritance pattern highlights the role of ANKH gene variants in the pathogenesis of CPPD.

Implications:

• This discovery expands the known spectrum of ANKH mutations linked to CPPD.
• Understanding the genetic basis of CPPD can lead to improved diagnostic strategies and targeted therapies.
• Further research into ANKH function and pyrophosphate metabolism is warranted for managing this debilitating condition.