DRC1 (dynein regulatory complex subunit 1) is a critical structural component of the nexin-dynein regulatory complex (N-DRC), which regulates ciliary and flagellar motility by maintaining axonemal integrity and coordinating microtubule sliding 1. DRC1 coassembles with DRC2 to form a central scaffold essential for N-DRC assembly and attachment to outer doublet microtubules, while stabilizing inner dynein arms and radial spokes 1. Mechanistically, DRC1 functions as a master regulator of axonemal structure; its loss causes dyskinetic ciliary beating with reduced frequency and complete axonemal structural disorder in flagella, though cilia remain functional despite impaired motility 1. DRC1 deficiency causes primary ciliary dyskinesia (PCD) and multiple morphological abnormalities of sperm flagella (MMAF) 123. A recurrent founder deletion of exons 1-4 accounts for ~97% of Japanese and Korean PCD cases, originating approximately 3,050 years ago 45. DRC1 variants also cause non-syndromic male infertility; a recurrent North African frameshift variant causes severe asthenozoospermia without systemic PCD symptoms 6. Clinically, DRC1-associated infertility responds favorably to intracytoplasmic sperm injection, enabling successful pregnancies 36, making genetic screening crucial for population-specific variants in infertile patients.