Analysis of the clinical features of Japanese patients with primary ciliary dyskinesia.

OBJECTIVE: Primary ciliary dyskinesia (PCD) is a rare hereditary disease. Most reports of PCD in Japan are case reports, and clinical analysis has not been performed. Differences in the causative genes might affect the clinical features in different ethnic groups. The purpose of this study was to clarify the clinical features of Japanese patients with PCD. METHODS: We performed a retrospective chart review of PCD patients seen at Mie University Hospital and patients whose blood samples were sent to us for genetic analysis from 2011 to 2020. Data on the following items were collected and analyzed: age at first visit to the hospital, age at diagnosis of PCD, process of referral to our facility, chief complaint, situs status, PrImary CiliARy DyskinesiA Rule (PICADAR) score, nasal nitric oxide concentration, otoscopic findings, rhinoscopic findings, and paranasal computed tomography scan findings. RESULTS: Sixty-seven patients (24 male, 43 female) were diagnosed with PCD during the study period. Age at diagnosis ranged from 2 months to 69 years (median, 17 years). Respiratory symptoms (77%) were the most common complaint, followed by nasal (15%) and aural (8%) symptoms. Situs inversus was present in 17 (25%) cases. Only 2 cases had congenital cardiac anomalies. The mean PICADAR score was 7.3 (range, 3-14) points. Approximately 50% of tympanic membranes showed retraction, suggesting otitis media with effusion. The mean Lund-Mackay score was 12.8 (range, 7-17) points, suggesting that the radiographic findings were not always severe. There was no significant difference in the total Lund-Mackay score between patients with and without situs inversus (12.7 vs. 12.6, respectively). CONCLUSION: Situs inversus was present in 25% of Japanese PCD patients, which is much lower than observed in other countries. This is a result of differences in the major disease-causing genes. The general rule that "situs inversus is observed in approximately 50% of PCD patients" cannot be applied, at least, in Japanese PCD patients.

Copy number variation in DRC1 is the major cause of primary ciliary dyskinesia in the Japanese population.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare genetic disorder caused by functional impairment of cilia throughout the body. The involvement of copy number variation (CNV) in the development of PCD is largely unknown. METHODS: We examined 93 Japanese patients with clinically suspected PCD from 84 unrelated families. CNV was examined either by exome sequencing of a PCD gene panel or by whole-exome sequencing (WES). The identified alterations were validated by PCR and Sanger sequencing. Nasal ciliary ultrastructure was examined by electron microscopy. RESULTS: Analysis of CNV by the panel or WES revealed a biallelic deletion in the dynein regulatory complex subunit 1 (DRC1) gene in 21 patients, which accounted for 49% of the PCD patients in whom a disease-causing gene was found. Sanger sequencing of the PCR product revealed a 27,748-bp biallelic deletion including exons 1-4 of DRC1 with identical breakpoints in all 21 patients. The ciliary ultrastructure of the patients with this CNV showed axonemal disorganization and the loss or gain of central microtubules. CONCLUSION: The deletion of DRC1 is the major cause of PCD in Japan and this alteration can cause various ciliary ultrastructural abnormalities.

A Case of Pyriform Sinus Fistula with Respiratory Distress in the Neonatal Period.

Pyriform sinus fistula (PSF) is an anomaly that can arise due to failure of involution of the third or fourth branchial cleft during embryogenesis. It can manifest clinically as sinuses, cysts, or abscesses in the neck and is common in childhood. Herein, we describe a neonate who presented with neck swelling and respiratory distress, which was secondary to a fourth branchial pouch sinus. Physical examination revealed swollen areas in the posterolateral pharyngeal wall and on the external left side of the neck. Computed tomography imaging showed a left-sided mass that was filled with air and fluid. Eventually, the pyriform sinus cyst and the entire fistulous tract were excised. The postoperative course was uneventful. Follow-up after 18 months showed no recurrence.

Endoscopic electrocauterization of pyriform sinus fistula.

To determine the efficacy of endoscopic electrocauterization for pyriform sinus fistula (PSF) using a flexible Bugbee cautery electrode. From 2009 to 2016, a total of eight patients with acute suppurative thyroiditis or cervical abscess secondary to PSF were retrospectively registered in our study (three males, five females; median age 6.5 years). All patients underwent endoscopic electrocauterization as treatment for PSF. Six of eight patients had no recurrence after the initial endoscopic electrocauterization of PSF. One patient with recurrence developed symptoms 9 days after cauterization and another experienced recurrence after 2 years. Mean follow-up for the eight patients was 50 months (range 5-96 months). No post-operative complication was reported. Endoscopic electrocauterization appears to be a less-invasive, safe, and effective method for the treatment of PSF.

Use of a Rigid Curved Laryngoscope for Removal of a Fish Bone in the Hypopharynx.

Foreign body ingestion is a commonly encountered clinical problem. In particular, sharp foreign bodies lodged in the esophagus or hypopharynx can cause complications and require urgent removal. Removal by flexible esophagogastroduodenoscopy or rigid esophagoscopy is the treatment of choice and has high success rates, but cases in which these methods are unsuccessful must be treated with an external incision. A 62-year-old man was referred for a fish bone lodged in the hypopharynx that could not be removed by flexible esophagogastroduodenoscopy. We removed the bone transorally using a specially designed rigid curved laryngoscope. Based on our experience, this method may have clear practical value due to advantages of a wide field of view and use of multiple rigid forceps. Indications may be limited, but this novel method may reduce the limitations of noninvasive removal of foreign bodies.

[Intraoperative CT Is Useful in Diagnosing a Fish Bone Foreign Body Buried in the Tongue: A Case Report].

Fish bones as a foreign body are often present in the palatine tonsil and the base of the tongue. Such foreign bodies can often be diagnosed with inspection only. However, it is difficult to diagnose and extirpate a foreign body when it is buried in the oral/pharyngeal mucosa. We experienced a case of a fish bone foreign body buried in the tongue muscle layer. We report herein on the case of a 49-year-old man with a fish bone foreign body buried in his tongue. The patient had noticed a sore throat since eating a sea bream and was referred to our department. Visual inspection revealed no foreign body, but CT imaging revealed a fish bone in the tongue. We performed an emergency surgical exploration of tongue to locate the fish bone. Because the fish bone as a foreign body was unable to be confirmed by palpation, we identified the location of the fish bone by intraoperative CT. This is a rare case of a fish bone buried in the tongue muscle layer, and intraoperative CT was useful in identifying the positon of the foreign body.