Eustachian Tube Growth and Development: Anatomy/Function. Protocol Description. This study measures Eustachian tube function and facial growth over time in three groups of children: one with recurrent ear infections, one with chronic middle ear fluid, and one with little past history of otitis media.
Causes of Kartagener syndrome. Kartagener syndrome is caused by a mutation in the DNAI1 gene, which makes a cellular protein required for normal functioning cilia (cilia line the respiratory tract) and sperm motility.
Histidinemia is caused by mutations in the HAL gene, which provides instructions for making an enzyme called histidase. Histidase breaks down histidine to a molecule called urocanic acid. Histidase is active (expressed) primarily in the liver and the skin. HAL gene mutations lead to the production of a histidase enzyme that cannot break down histidine, which results in elevated levels of histidine in the blood and urine.