Recurrent diffuse lung disease due to surfactant protein C deficiency

Area of Science:

• Pulmonology
• Genetics
• Cell Biology

Background:

• Surfactant protein C (SP-C) deficiency is a rare genetic disorder causing diffuse lung disease, typically presenting in infancy with variable severity.
• Alveolar type II cells, crucial for lung repair, are injured by mutated SP-C accumulation, impairing the replenishment of alveolar type I cells.

Observation:

• A patient with diffuse lung disease, initially treated in infancy, presented with recurrent respiratory symptoms in young adulthood.
• Exome sequencing revealed a novel de novo SFTPC mutation (c.397A>C p.S133R) in the patient.

Findings:

• The identified SFTPC mutation leads to the accumulation of mutated SP-C.
• Accumulated mutated SP-C causes injury to alveolar type II cells, impairing lung repair mechanisms.
• This cellular mechanism may explain the recurrence of symptoms in young adulthood following lung injury.

Implications:

• This case highlights the potential for diffuse lung disease due to SFTPC mutations to manifest or recur in adulthood.
• The findings suggest a need for long-term monitoring of patients with SP-C deficiency.
• Further research is needed to understand the long-term efficacy of treatments like hydroxychloroquine for mutated SP-C accumulation.