Ectopic thyroid tissue: unusual differential diagnosis of cervical paraganglioma

Ectopic thyroid tissue (ETT) lateral to the midline is rare. Its occurrence in the carotid bifurcation is exceptional. We present a 45 years woman who consulted with a slow growing right cervical swelling. Clinical examination Ultrasonography, contrast enhanced CT and cervical MRI concluded to a paraganglioma. Intra-operatively, the tumor didn't have the characteristic aspect of a paraganglioma. Complete excision was performed. Histology concluded to an ectopic micro-vesicular thyroid adenoma.Previous literature was reviewed to summarize clinical and radiologic characteristics of such rare entity. Despite its rarity, ETT must be included in the differential diagnosis of cervical paraganglioma.Keywords: Ectopic thyroid, MRI, paraganglioma, surger

Paraganglioma of the carotid body: Report of 26 patients and review of the literature

Introduction: Paragangliomas are extra-adrenal tumors originating from the neuro-ectoderm, occurring from the skull base to the pelvic floor. In the head and neck region, they are found at the jugular bulb, the vagal and tympanic nerves and the aortic glomus. Objectives: The aim of the present study was to review clinical profile, treatment outcomes and long-term follow-up in patients with paragangliomas of the carotid body. Materials and methods: It is about a retrospective study of 26 patients (28 paragangliomas) followed and treated in Ear, Nose and Throat Department of La Rabta Hospital. Pre-, intra- and postoperative findings were analyzed. Results: The present study included 6 men and 20 women. Bilateral involvement of the carotid glomus was noted in 2 cases and tympano-jugular location was associated in 2 other cases. Ultrasound of the neck, computed tomography (CT) and magnetic resonance (MR) tomography were performed in 13, 17 and 10 cases, respectively. 2 patients have had preoperative embolization and 22 patients, in total, were operated. External radiation was an exclusive therapeutic option in 2 patients and adjuvant to incomplete surgery in one patient. Only one case of malignant paraganglioma was noted that evolution was, in fact, rapidly fatal

Compound heterozygosity for dominant and recessive GJB2 mutations in a Tunisian family and association with successful cochlear implant outcome.

International audienceOBJECTIVES: Mutations of GJB2 encoding connexin 26 are the most common cause of hearing loss. They are responsible for up to 50% of ARNSHL. The pathogenic mutations in this gene are generally inherited recessively. Dominant mutations in GJB2 also cause hearing loss, either in isolated non-syndromic form or as part of a syndrome associated with various skin disorders. METHODS: We screened a Tunisian child affected by congenital, bilateral, profound, sensorineural hearing loss for mutations in GJB2 gene using PCR and direct sequencing. RESULTS: The proband was found to be compound heterozygous for recessive and dominant GJB2 mutations respectively p.V37I (c.109G>A) and p.R143Q (c.428G>A). Surprisingly the hearing mother is a carrier for this dominant GJB2 mutation. This proband underwent a cochlear implant at four years old. The evaluation using APCEI and IT-MAIS tests at six months post implantation indicates a successful cochlear implant outcome since the deaf child began to acquire language abilities and auditory sensation. CONCLUSIONS: The p.R143Q mutation was described for the first time in Tunisia. We confirm the low penetrance of this mutation since the proband mother is a carrier despite her normal hearing. We show the effectiveness of cochlear implant to restore the communication abilities and auditory sensation for our patient

A novel frameshift mutation (c.405delC) in the GJB2 gene associated with autosomal recessive hearing loss in two Tunisian families.

International audienceOBJECTIVES: Mutations in GJB2 are found to be responsible for 50% of congenital autosomal recessive non-syndromic hearing loss, one of the most important mutations in this gene is the c.35delG, which is responsible for the majority of GJB2 related deafness in the Tunisian population. The aim of this study was to determine the molecular etiology of hearing loss in two Tunisian individuals. METHODS: We screened two Tunisian individuals affected by congenital, bilateral, profound, sensorineural hearing loss for mutations in GJB2 gene using PCR and direct sequencing. RESULTS: We identified a novel frameshift mutation in the GJB2 gene, the c.405delC resulting in a truncated protein (p.Tyr136Thrfs*32). It was found in compound heterozygosity with the c.35delG in two non-consanguineous unrelated families from Tunisia. One patient underwent a cochlear implant at 4 years. Initial evaluations post-implantation indicate a successful cochlear implant outcome since the patient began to acquire language abilities and auditory sensation. CONCLUSIONS: With this novel GJB2 mutation, the mutational spectrum of this gene continues to broaden in our population. The occurrence of biallelic GJB2 mutations for the other deaf girl, despite the neonatal pain and hypotension due to complicated delivery, led us to confirm the importance of GJB2 screening for cochlear implant candidates regardless of the etiology of deafness in populations with a relatively high frequency of GJB2 mutation carriers

Whole exome sequencing identifies mutations in Usher syndrome genes in profoundly deaf Tunisian patients.

Usher syndrome (USH) is an autosomal recessive disorder characterized by combined deafness-blindness. It accounts for about 50% of all hereditary deafness blindness cases. Three clinical subtypes (USH1, USH2, and USH3) are described, of which USH1 is the most severe form, characterized by congenital profound deafness, constant vestibular dysfunction, and a prepubertal onset of retinitis pigmentosa. We performed whole exome sequencing in four unrelated Tunisian patients affected by apparently isolated, congenital profound deafness, with reportedly normal ocular fundus examination. Four biallelic mutations were identified in two USH1 genes: a splice acceptor site mutation, c.2283-1G>T, and a novel missense mutation, c.5434G>A (p.Glu1812Lys), in MYO7A, and two previously unreported mutations in USH1G, i.e. a frameshift mutation, c.1195_1196delAG (p.Leu399Alafs*24), and a nonsense mutation, c.52A>T (p.Lys18*). Another ophthalmological examination including optical coherence tomography actually showed the presence of retinitis pigmentosa in all the patients. Our findings provide evidence that USH is under-diagnosed in Tunisian deaf patients. Yet, early diagnosis of USH is of utmost importance because these patients should undergo cochlear implant surgery in early childhood, in anticipation of the visual loss

Whole exome sequencing identifies new causative mutations in Tunisian families with non-syndromic deafness.

Identification of the causative mutations in patients affected by autosomal recessive non syndromic deafness (DFNB forms), is demanding due to genetic heterogeneity. After the exclusion of GJB2 mutations and other mutations previously reported in Tunisian deaf patients, we performed whole exome sequencing in patients affected with severe to profound deafness, from four unrelated consanguineous Tunisian families. Four biallelic non previously reported mutations were identified in three different genes: a nonsense mutation, c.208C>T (p.R70X), in LRTOMT, a missense mutation, c.5417T>C (p.L1806P), in MYO15A and two splice site mutations, c.7395+3G>A, and c.2260+2T>A, in MYO15A and TMC1 respectively. We thereby provide evidence that whole exome sequencing is a powerful, cost-effective screening tool to identify mutations causing recessive deafness in consanguineous families

Retinal phenotypes of patients with mutations in Usher genes.

<p><b>A</b>, Composite color fundus photograph of the left eye of a four-year-old girl (DF103-III-2) showing diffuse narrowing of the retinal arteries and hyperpigmentation in a bone-spicule configuration in the midperipheral retina. <b>B</b>, B-scan OCT imaging of the same eye showing a mild foveal atrophy (central macular thickness = 160 micrometers). <b>C</b>, Color fundus photograph of the posterior pole of the right eye of a six-year-old boy (DF103-III-1) with early stage retinitis pigmentosa shows no obvious abnormalities which may explain the misdiagnosis of the disease in some cases. <b>D</b>, Color fundus photograph of the peripheral retina showing a “salt and pepper" appearance without the classical bone-spicule pigmentation. <b>E</b>, The fovea has a normal thickness on optical coherence tomography (180 micrometers).</p

Pedigrees of the four Tunisian patients analyzed by whole exome sequencing.

<p>Squares and circles denote males and females, respectively. Filled symbols indicate deaf individuals. Arrows indicate the individuals analyzed by WES.</p

Evolution of the number of variants during whole exome.

<p>Evolution of the number of variants during whole exome.</p

Biallelic mutations identified in DFNB genes using a whole exome sequencing strategy.

<p>Biallelic mutations identified in DFNB genes using a whole exome sequencing strategy.</p