Novel gene mutations in patient with pulmonary alveolar microlithiasis: a case report and literature review

Pulmonary Alveolar Microlithiasis (PAM) is a rare hereditary lung disorder characterized by the intra-alveolar deposition of calcium phosphate microliths. It is primarily familial and follows an autosomal recessive inheritance pattern, with no significant gender disparity in incidence. In its early stages, PAM is often asymptomatic, and most cases are detected incidentally through abnormal imaging findings during routine health examinations. We report a case of a male patient under the age of 60 with a 10-year history of exertional dyspnea and cough unresponsive to conventional therapy. Initially diagnosed and treated for emphysema in January 2024, the patient was readmitted two months later with progressive dyspnea and cyanosis. The diagnosis of PAM was confirmed by typical meadical imaging and pathological examination. Genetic analysis identified novel compound heterozygous SLC34A2 mutations: a c.910A > T (p.Lys304*) nonsense mutation in exon 8 and a heterozygous ~ 5.5 kb copy-number deletion at 4p15.2, thereby expanding the catalogue of reported PAM-associated mutations. No recurrence was observed during one-year follow-up.