Rationale: Primary ciliary dyskinesia (PCD) is a rare, usually autosomal recessive, genetic disorder characterized by ciliary dysfunction, sino-pulmonary disease, and situs inversus. Disease-causing mutations have been reported in DNAI1 and DNAH5 encoding outer dynein arm (ODA) proteins of cilia. Objectives: We analyzed DNAI1 to identify disease-causing mutations in PCD and to determine if the previously reported IVS1؉2_3insT (219؉3insT) mutation represents a "founder" or "hot spot" mutation. Methods: Patients with PCD from 179 unrelated families were studied. Exclusion mapping showed no linkage to DNAI1 for 13 families; the entire coding region was sequenced in a patient from the remaining 166 families. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed on nasal epithelial RNA in 14 families. Results: Mutations in DNAI1 including 12 novel mutations were identified in 16 of 179 (9%) families; 14 harbored biallelic mutations. Deep intronic splice mutations were not identified by reverse transcriptase-polymerase chain reaction. The prevalence of mutations in families with defined ODA defect was 13%; no mutations were found in patients without a defined ODA defect. The previously reported IVS1؉2_3insT mutation accounted for 57% (17/30) of mutant alleles, and marker analysis indicates a common founder for this mutation. Seven mutations occurred in three exons (13, 16, and 17); taken together with previous reports, these three exons are emerging as mutation clusters harboring 29% (12/42) of mutant alleles. Conclusions: A total of 10% of patients with PCD are estimated to harbor mutations in DNAI1; most occur as a common founder IVS1؉2_3insT or in exons 13, 16, and 17. This information is useful for establishing a clinical molecular genetic test for PCD.

Few studies have evaluated the quality of life of patients with primary ciliary dyskinesia (PCD). We sought to determine the health impact of the disease as well as the unmet needs in a large group of patients.Questionnaires were either posted or e-mailed to known patients with PCD and published online. Questionnaires included the St George's Respiratory Questionnaire, the Medical Outcomes Study Short Form-36 and a questionnaire that we produced to obtain information on age of diagnosis, symptoms and likely PCD-specific problems of these patients.78 subjects (96% of those invited) answered all the questionnaires. Patients were diagnosed at a mean age of 9.4 yrs. Progressive worsening of the disease was observed and adherence to physiotherapy was found to be poor, particularly in adolescents and adults. Patients with the highest treatment burden had a worse quality of life. Over time patients become progressively less interested in treating their disease and adherence to treatment modalities decreases.PCD is associated with a progressive and continuous impact on the physical and mental health of the patients. Earlier identification of the patients and better strategies aimed at improving compliance with care are urgently needed.