原発性線毛運動不全症を正しく診断するために

抄録

Primary ciliary dyskinesia (PCD) is a hereditary disorder caused by biallelic mutations of genes related to the cilia. The estimated prevalence of PCD is 1 in 20,000 live births. In cases without situs inversus, the diagnosis can be very difficult. In Japan, PCD without situs inversus is underdiagnosed at present. In many cases reported in Japan, the diagnosis of PCD is based only on detection of inner dynein arm defect by electron microscopy. Since the inner dynein arms may not be visualized even in normal subjects, diagnosis based on this finding alone needs further validation. Since PCD is a hereditary disease, a diagnosis of this condition would not only have an impact on the patients themselves, but also on his/her family members. Thus, caution should be exercised in making the diagnosis of PCD. Otorhinolaryngologists inspect nasal cavities and eardrums in daily practice, and can perform the biopsies necessary for the diagnosis by electron microscopy. For making a definitive diagnosis of PCD, nasal nitric oxide concentration measurement, electron-microscopic study of the cilia, and genetic tests are required. Taking all these aspects into consideration, I firmly believe that a correct diagnosis of PCD is of great importance. Therefore, basic knowledge about cilia and three kinds of diagnostic criteria are explained. Tips for obtaining biopsy specimens for electron microscopy are shown. Since there is a known correlation between genetic changes and ciliary ultrastructure, it is desirable that both tests be performed and that the test results are compatible. At present, no specific therapies are available for PCD. In the near future, treatment based on genetic mutational changes may be developed as personalized medicine. Making a genetic diagnosis is important for each patient to receive such treatment.