In which condition is there a lack of dynein arms and loss of ciliary spokes?

The presence of a lack of dynein arms and loss of ciliary spokes is characteristic of primary ciliary dyskinesia. This genetic disorder affects the structure and function of cilia, which are important for the movement of mucus and other substances in the respiratory tract. Dynein arms are critical components of cilia that facilitate their beating motion, and without them, cilia cannot function properly. Consequently, this leads to impaired mucociliary clearance and results in a range of respiratory issues, including chronic infections, bronchiectasis, and sinusitis.

In contrast, cystic fibrosis, bronchiectasis, and maxillary sinusitis are conditions that result from other pathophysiological processes but do not specifically involve the structural defects in cilia described in the prompt. Cystic fibrosis is primarily characterized by mutations in the CFTR gene, leading to thickened secretions, and bronchiectasis refers to the abnormal widening of the bronchi often due to chronic inflammation or infection rather than a primary defect of cilia. Maxillary sinusitis is an inflammation of the sinuses that may occur as a complication of conditions like viral infections or allergies, but again, it does not relate to the absence of dynein arms or ciliary