Diagnostic and therapeutic applications of genomic medicine in progressive, late-onset, nonsyndromic sensorineural hearing loss.

The progressive, late-onset, nonsyndromic, sensorineural hearing loss (PNSHL) is the most common cause of sensory impairment globally, with presbycusis affecting greater than a third of individuals over the age of 65. The etiology underlying PNSHL include presbycusis, noise-induced hearing loss, drug ototoxicity, and delayed-onset autosomal dominant hearing loss (AD PNSHL). The objective of this article is to discuss the potential diagnostic and therapeutic applications of genomic medicine in PNSHL. Genomic factors contribute greatly to PNSHL. The heritability of presbycusis ranges from 25 to 75%. Current therapies for PNSHL range from sound amplification to cochlear implantation (CI). PNSHL is an excellent candidate for genomic medicine approaches as it is common, has well-described pathophysiology, has a wide time window for treatment, and is amenable to local gene therapy by currently utilized procedural approaches. AD PNSHL is especially suited to genomic medicine approaches that can disrupt the expression of an aberrant protein product. Gene therapy is emerging as a potential therapeutic strategy for the treatment of PNSHL. Viral gene delivery approaches have demonstrated promising results in human clinical trials for two inherited causes of blindness and are being used for PNSHL in animal models and a human trial. Non-viral gene therapy approaches are useful in situations where a transient biologic effect is needed or for delivery of genome editing reagents (such as CRISPR/Cas9) into the inner ear. Many gene therapy modalities that have proven efficacious in animal trials have potential to delay or prevent PNSHL in humans. The development of new treatment modalities for PNSHL will lead to improved quality of life of many affected individuals and their families.

Precision medicine in hearing loss.

Precision medicine (PM) proposes customized medical care based on a patient's unique genome, biomarkers, environment and behaviors. Hearing loss (HL) is the most common sensorineural disorder worldwide and is frequently caused by a single genetic mutation. With recent advances in PM tools such as genetic sequencing and data analysis, the field of HL is ideally positioned to adopt the strategies of PM. Here, we review current and future applications of PM in HL as they relate to the four core qualities of PM (P4): predictive, personalized, patient-centered, and participatory. We then introduce a strategy for effective incorporation of HL PM into the design of future research studies, electronic medical records, and clinical practice to improve diagnostics, prognostics, and, ultimately, individualized patient treatment. Finally, specific anticipated ethical and economic concerns in this growing era of genomics-based HL treatment are discussed. By integrating PM principles into translational HL research and clinical practice, hearing specialists are uniquely positioned to effectively treat the heterogeneous causes and manifestations of HL on an individualized basis.

Genetic basis of hearing loss in Spanish, Hispanic and Latino populations.

Hearing loss (HL) is the most common neurosensory disorder affecting humans. The screening, prevention and treatment of HL require a better understanding of the underlying molecular mechanisms. Genetic predisposition is one of the most common factors that leads to HL. Most HL studies include few Spanish, Hispanic and Latino participants, leaving a critical gap in our understanding about the prevalence, impact, unmet health care needs, and genetic factors associated with hearing impairment among Spanish, Hispanic and Latino populations. The few studies which have been performed show that the gene variants commonly associated with HL in non-Spanish and non-Hispanic populations are infrequently responsible for hearing impairment in Spanish as well as Hispanic and Latino populations (hereafter referred to as Hispanic). To design effective screening tools to detect HL in Spanish and Hispanic populations, studies must be conducted to determine the gene variants that are most commonly associated with hearing impairment in this racial/ethnic group. In this review article, we summarize gene variants and loci associated with HL in Spanish and Hispanic populations. Identifying new genetic variants associated with HL in Spanish and Hispanic populations will pave the way to develop effective screening tools and therapeutic strategies for HL.

The genetic basis of deafness in populations of African descent.

Hearing loss is the most common sensorineural disorder worldwide and is associated with more than 1000 mutations in more than 90 genes. While mutations in genes such as GJB2 (gap-junction protein ß 2) and GJB6 (gap-junction protein ß 6) are highly prevalent in Caucasian, Asian, and Middle Eastern populations, they are rare in both native African populations and those of African descent. The objective of this paper is to review the current knowledge regarding the epidemiology and genetics of hearing loss in African populations with a focus on native sub-Saharan African populations. Environmental etiologies related to poor access to healthcare and perinatal care account for the majority of cases. Syndromic etiologies including Waardenburg, Pendred and Usher syndromes are uncommon causes of hearing loss in these populations. Of the non-syndromic causes, common mutations in GJB2 and GJB6 are rarely implicated in populations of African descent. Recent use of next-generation sequencing (NGS) has identified several candidate deafness genes in African populations from Nigeria and South Africa that are unique when compared to common causative mutations worldwide. Researchers also recently described a dominant mutation in MYO3a in an African American family with non-syndromic hearing loss. The use of NGS and specialized panels will aid in identifying rare and novel mutations in a more cost- and time-effective manner. The identification of common hearing loss mutations in indigenous African populations will pave the way for translation into genetic deafness research in populations of African descent worldwide.

Lipoma and liposarcoma of the larynx: case reports and literature review.

OBJECTIVE: Two cases of laryngeal lipomatous tumors are presented. Their diagnoses and management are discussed and contrasted. METHODS: Case report and literature review. RESULTS: Patient 1 is a 58 year old male presenting with five years of progressive shortness of breath, dysphagia, and globus sensation. Clinical exam and imaging study showed a 3.5 cm hypodense laryngeal mass, and he underwent transoral robotic-assisted surgery for complete excision. Final pathology revealed a well-differentiated liposarcoma. Patient 2 is a 79 year old female presenting with one year of non-progressive hoarseness and globus sensation. Clinical examination and imaging study revealed a 1.8 cm hypodense laryngeal mass. Transoral endoscopic complete excision of the submucosal mass was performed. Final pathology revealed benign spindle-cell lipoma. CONCLUSION: Liposarcoma and lipoma may present with similar symptomatology, clinical, and imaging findings. Pathology evaluation is of utmost importance for definitive diagnosis. Therefore, diagnosis and treatment of laryngeal lipomatous lesions are best accomplished with complete excision of the mass.

Surgical Techniques for Zenker's Diverticulum: A Comparative Analysis.

OBJECTIVE: To compare the different modalities for treatment of Zenker's diverticulum and the associated clinical outcomes. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care hospital. SUBJECTS AND METHODS: Between 1995 and 2011, 164 patients underwent surgery for Zenker's diverticulum (stapler, n = 69; laser, n = 68; open, n = 27). Patient sociodemographics, medical comorbidities, pre- and postoperative subjective dysphagia and regurgitation score, complications, length of stay, time to oral intake, and recurrence were reviewed for each surgical modality. RESULTS: No statistically significant difference in diverticulum prevalence was associated with age, gender, or treatment group. Mean length of hospital stay was not significantly different between the 3 groups (P = .14). A significant difference in time to oral intake was observed in the laser group compared with the other 2 groups (P = .012). No significant difference in recurrence (P = .21) or complication (P = .12) rates was identified between the 3 groups. Although all 3 groups demonstrated a significant decrease between preoperative and postoperative dysphagia and regurgitation scores, the degree of improvement was not significant when the 3 groups were compared. CONCLUSION: There is no single "best" approach to Zenker's diverticulum. The open, laser, and stapler methods are equally effective and have similar complication rates.