WFS1 mutation screening in a large series of Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis

A heterozygous mutation in the Wolfram syndrome type 1 gene (WFS1) causes autosomal dominant nonsyndromic hereditary hearing loss, DFNA6/14/38, or Wolfram-like syndrome. To date, more than 40 different mutations have been reported to be responsible for DFNA6/14/38. In the present study, WFS1 variants were screened in a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA6/14/38 and Wolfram-like syndrome. Massively parallel DNA sequencing of 68 target genes was performed in 2,549 unrelated Japanese HL patients to identify genomic variations responsible for HL. The detailed clinical features in patients with WFS1 variants were collected from medical charts and analyzed. We successfully identified 13 WFS1 variants in 19 probands: eight of the 13 variants were previously reported mutations, including three mutations (p.A684V, p.K836N, and p.E864K) known to cause Wolfram-like syndrome, and five were novel mutations. Variants were detected in 15 probands (2.5%) in 602 families with presumably autosomal dominant or mitochondrial HL, and in four probands (0.7%) in 559 sporadic cases; however, no variants were detected in the other 1,388 probands with autosomal recessive or unknown family history. Among the 30 individuals possessing variants, marked variations were observed in the onset of HL as well as in the presence of progressive HL and tinnitus. Vestibular symptoms, which had been rarely reported, were present in 7 out of 30 (23%) of the affected individuals. The most prevalent audiometric configuration was low-frequency type; however, some individuals had high-frequency HL. Haplotype analysis in three mutations (p.A716T, p.K836T, and p.E864K) suggested that the mutations occurred at these mutation hot spots. The present study provided new insights into the audiovestibular phenotypes in patients with WFS1 mutations.

Guiding principles of sublingual immunotherapy for allergic rhinitis in Japanese patients

OBJECTIVE

Sublingual immunotherapy (SLIT) appears to offer practical advantages for the treatment of allergic rhinitis (AR). Based on a review of the scientific literature, we present recommendations as guiding principles to administer SLIT safely.

METHODS

Clinical questions concerning SLIT were prepared. Literature published between January 2003 and December 2012 was searched from PubMed, the Cochrane Library, and Japana Centra Revuo Medicina. Qualified studies were analyzed and the results were evaluated, consolidated, and codified. We answered 17 clinical questions and, based on this, presented evidence-based recommendations.

RESULTS

Sublingual immunotherapy improved symptoms (e.g., quality of life [QOL]) and reduced medication scores in seasonal AR and perennial AR. Most SLIT-induced adverse effects were local oral reactions, although systemic adverse effects such as gastrointestinal symptoms, urticaria, and asthma are occasionally reported. There have been no reports of lethal anaphylactic reactions by SLIT. When SLIT is continued for 3-4 years, its effect persists long after discontinuation.

CONCLUSION

A correct diagnosis of AR and sufficient informed consent from patients are required before initiating SLIT. Sublingual immunotherapy should be continued for 3 years or longer. The initial administration of SLIT during the uptitration of an allergen vaccine and the general condition of patients are critical for the safe performance of SLIT.

Novel Mutations in GRXCR1 at DFNB25 Lead to Progressive Hearing Loss and Dizziness

Objective:

We identified 2 patients in 1 family who had novel mutations in GRXCR1, which caused progressive hearing loss.

Methods:

One thousand one hundred twenty Japanese hearing loss patients with sensorineural hearing loss from unrelated families were enrolled in this study. Targeted genomic enrichment with massively parallel sequencing of all known nonsyndromic hearing loss genes was used to identify the genetic causes of hearing loss.

Results:

In this study, 2 affected individuals with compound heterozygous mutations—c.439C>T (p.R147C) and c.784C>T (p.R262X)—in GRXCR1 were identified. The proband had moderate to severe hearing loss and suffered from dizziness with bilateral canal paralysis.

Conclusion:

Our cases are the first identified in the Japanese population and are consistent with previously reported cases. The frequency of mutations in GRXCR1 seems to be extremely rare. This study underscores the importance of using comprehensive genetic testing for hearing loss. Furthermore, longitudinal audiologic assessment and precise vestibular testing are necessary for a better understanding of the mechanisms of hearing loss and vestibular dysfunction caused by GRXCR1 mutations.

[A case of pediatric recurrent acute mastoiditis caused by penicillin-resistant Streptococcus pneumonia complicated by primary immunodeficiency]

Penicillin-resistant Streptococcus pneumoniae (PRSP) is a frequently detected pathogen of intractable acute otitis media and is associated with prolonged or recurrent infection. The use of antibiotics has made the incidence of secondary acute mastoiditis following acute otitis media relatively rare, but when it does occur, its severe complications may be life-threatening. We report a case of pediatric recurrent acute mastoiditis caused by PRSP in a 6-year-old boy suffering from PRSP acute mastoiditis on 4 occasions, twice undergoing simple mastoidectomy. Although we initially suspected PRSP to be the chief factor in iterative infection, immunological analysis demonstrated significantly decreased IgG and IgA antibodies in serum and the patient was diagnosed as having common variable immunodeficiency (CVID). As the first middle ear infection occurred at the age of 6 and there was no history of upper respiratory tract infection, CVID may be the main pathological factor of recurrent mastoiditis, although infection occurred, only in the ear and did not involve other organs. This suggests that recurrent mastoiditis in the present case involved the coexistence of PRSP and CVID.

Application of YAMIK sinus catheter for patients with paranasal sinusitis with and without nasal allergy

PURPOSE

YAMIK sinus catheter (YAMIK) has already been reported to be a useful therapeutic device for sinusitis cases. The purpose of this study was to compare the effectiveness of YAMIK in sinusitis cases with and without nasal allergy in order to contribute toward establishing its indication.

METHODS

YAMIK was tried in 10 chronic sinusitis cases complicated with nasal allergy and 20 cases without nasal allergy. Clinical symptoms, endoscopic findings and pathological opacification in X-ray photographs were compared in these cases with and without nasal allergy.

RESULTS

No significant differences were seen in the effectiveness of YAMIK between cases with and without nasal allergy.

CONCLUSION

These findings suggest that YANIK is useful and applicable even in sinusitis cases complicated with nasal allergy.