Bronchiectasis in a child with a homozygous DCDC2 gene mutation: A case report

The <i>DCDC2 (Doublecortin Domain-Containing Protein 2)</i> gene encodes a ciliary protein involved in microtubule polymerization and ciliary assembly. Although <i>DCDC2</i> has been associated primarily with neuronal migration and ciliopathies affecting the liver and kidneys, its role in pulmonary disease has not been clearly defined. Ciliary dysfunction, particularly in motile cilia of the respiratory tract, can impair mucociliary clearance and lead to bronchiectasis, as seen in primary ciliary dyskinesia. Here, we report a rare case of bronchiectasis associated with a pathogenic <i>DCDC2</i> (NM_016356.5):c.558del p.(Arg186SerfsTer5) variant, in which other known causes of bronchiectasis were excluded. This finding expands the phenotypic spectrum of <i>DCDC2</i>-related disease, and suggests a potential link between <i>DCDC2</i> mutations and respiratory involvement. Early recognition of this association might support timely pulmonary screening and intervention to improve long-term outcomes.