RESUMO
Primary ciliary dyskinesia (PCD) is a hereditary disease caused by genes related to motile cilia. We report two male pediatric cases of PCD caused by hemizygous pathogenic variants in the OFD1 centriole and centriolar satellite protein (OFD1) gene. The variants were NM_003611.3: c.[2789_2793delTAAAA] (p.[Ile930LysfsTer8]) in Case 1 and c.[2632_2635delGAAG] (p.[Glu878LysfsTer9]) in Case 2. Both cases had characteristic recurrent respiratory infections. Neither case had symptoms of oral-facial-digital syndrome type I. We identified a variant (c.2632_2635delGAAG) that has not been previously reported in any case of OFD1-PCD.
RESUMO
OBJECTIVE: Primary ciliary dyskinesia (PCD) is a relatively rare genetic disorder that affects approximately 1 in 20,000 people. Approximately 50 genes are currently known to cause PCD. In light of differences in causative genes and the medical system in Japan compared with other countries, a practical guide was needed for the diagnosis and management of Japanese PCD patients. METHODS: An ad hoc academic committee was organized under the Japanese Rhinologic Society to produce a practical guide, with participation by committee members from several academic societies in Japan. The practical guide including diagnostic criteria for PCD was approved by the Japanese Rhinologic Society, Japanese Society of Otolaryngology-Head and Neck Surgery, Japanese Respiratory Society, and Japanese Society of Pediatric Pulmonology. RESULTS: The diagnostic criteria for PCD consist of six clinical features, six laboratory findings, differential diagnosis, and genetic testing. The diagnosis of PCD is categorized as definite, probable, or possible PCD based on a combination of the four items above. Diagnosis of definite PCD requires exclusion of cystic fibrosis and primary immunodeficiency, at least one of the six clinical features, and a positive result for at least one of the following: (1) Class 1 defect on electron microscopy of cilia, (2) pathogenic or likely pathogenic variants in a PCD-related gene, or (3) impairment of ciliary motility that can be repaired by correcting the causative gene variants in iPS cells established from the patient's peripheral blood cells. CONCLUSION: This practical guide provides clinicians with useful information for the diagnosis and management of PCD in Japan.