DNAAF2 (dynein axonemal assembly factor 2) is essential for cytoplasmic pre-assembly of axonemal dynein complexes before their transport into cilia and flagella 1. The protein functions as part of a conserved HSP90 co-chaperone complex that stabilizes and pre-assembles multi-subunit dynein arm motors in the cytoplasm, which are subsequently loaded into the ciliary compartment via intraflagellar transport 1. This pre-assembly process is critical for proper cilia and flagella motility. Mutations in DNAAF2 cause primary ciliary dyskinesia (PCD), an autosomal recessive disorder characterized by defective cilia motility 2. Patients with DNAAF2-related PCD present with respiratory tract infections, bronchiectasis, sinusitis, and approximately 40% experience laterality defects including situs inversus 23. The condition also causes male and female infertility due to impaired sperm motility and ciliary dysfunction 43. Recent studies have identified DNAAF2 variants in diverse populations and linked the gene to additional phenotypes including scoliosis 3. Loss of DNAAF2 function results in absence of both outer and inner dynein arms in cilia, leading to ciliary immotility 34. The gene represents a critical component for normal ciliary function and embryonic development.