Unraveling the Diversity of GJB2 Mutations in Nonsyndromic Hearing Loss: A Comprehensive Study in the Moroccan Population.

INTRODUCTION: Despite the high genetic heterogeneity of hearing loss, mutations in the GJB2 gene are a major cause of autosomal recessive nonsyndromic hearing loss (NSHL) worldwide. However, the mutation profile of GJB2 in NSHL is under-investigated in Morocco, especially among simplex cases. This study aimed to identify the spectrum and frequency of GJB2 mutations in the Moroccan population among simplex and multiplex families with NSHL. METHODS: Moroccan families with NSHL were selected according to well-defined criteria. Selected families were screened for GJB2 gene variants using direct sequencing of the entire coding region of GJB2. RESULTS: A total of 145 affected individuals from 115 families with NSHL were included in this study (49 simplex, 66 multiplex). Mutations in the GJB2 gene were noted in 28.69% of the families (33/115), of which 75.75% were multiplex families and 24.24% were simplex. In total, seven different mutations were detected: c.35delG(p.G12fs), c.551G>A(p.R184Q), c.139G>T(p.E47X), c.109G>A(p.V37I), c.167delT(p.L56fs), c.617A>G(p.N206S), c.94C>T(p.R32C). The last three mutations have not previously been reported in Morocco. The most common GJB2 mutation was c.35delG (21.73%), followed by p.V37I (2.60%) and p.E47X (1.73%). CONCLUSIONS: Our study confirms a high prevalence of GJB2 variants in the Moroccan population, particularly the c.35delG mutation. Additionally, we have identified previously unreported or rarely reported mutations, revealing a greater diversity of GJB2 mutations. These findings emphasize the importance of comprehensive screening beyond the 35delG mutation for patients with NSHL, regardless of their family history. Integrating this approach into clinical care will enhance diagnosis and management of hearing loss in the Moroccan population.

Vertebral artery dissection due to an esophageal foreign body migration: a case report.

Unintentional foreign bodies' swallowing is a fairly common occurrence in ENT consultation especially among children. They usually pass through the gastrointestinal tract without complications. Migration of a foreign body through the esophageal wall is rare. It represents about 1% to 4% of all cases of foreign bodies' ingestion. A 16 year's old female patient has presented to ENT emergency with a painful dysphagia following an accidental ingestion of a metallic pin. Cervical X ray confirmed the presence of the pin while endoscopic investigations have shown no foreign body. Cervical CT scan revealed the migration of the foreign body through the esophageal wall with left vertebral artery dissection. Endoscopic management has been sufficient with an uneventful post operative follow up. Esophageal foreign bodies are very diverse mainly dominated by fish bones (60%) and chicken bones (16%). Metallic pins are rare. The major risks of migration of those foreign bodies are cervical abscess, mediastinitis and oeso-vascular fistulae. Cases of self extrusion through the skin have been reported. Migration of a foreign body through the esophageal wall is rare. Endoscopic management has been sufficient.