Objective: To describe the genetic and phenotypic spectrum of Usher syndrome after 6 years of studies by next-generation sequencing, and propose an up-to-date classification of Usher genes in patients with both visual and hearing impairments suggesting Usher syndrome, and in patients with seemingly isolated deafness. Study Design: The systematic review and meta-analysis protocol was based on Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed 1) a meta-analysis of data from 11 next-generation sequencing studies in 684 patients with Usher syndrome; 2) a meta-analysis of data from 21 next-generation studies in 2,476 patients with seemingly isolated deafness, to assess the involvement of Usher genes in seemingly nonsyndromic hearing loss, and thus the proportion of patients at high risk of subsequent retinitis pigmentosa (RP); 3) a statistical analysis of differences between parts 1) and 2). Results: In patients with both visual and hearing impairments, the biallelic disease-causing mutation rate was assessed for each Usher gene to propose a classification by frequency: USH2A: 50% (341/684) of patients, MYO7A: 21% (144/684), CDH23: 6% (39/684), ADGRV1: 5% (35/684), PCDH15: 3% (21/684), USH1C: 2% (17/684), CLRN1: 2% (14/684), USH1G: 1% (9/684), WHRN: 0.4% (3/684), PDZD7 0.1% (1/684), CIB2 (0/684). In patients with seemingly isolated sensorineural deafness, 7.5% had disease-causing mutations in Usher genes, and are therefore at high risk of developing RP. These new findings provide evidence that usherome dysfunction is the second cause of genetic sensorineural hearing loss after connexin dysfunction. Conclusion: These results promote generalization of early molecular screening for Usher syndrome in deaf children.
The stapedial artery is an embryonic artery which disappears during the tenth week in utero, in human species. During its short life, this artery shapes the stapes and transforms the middle meningeal artery from the internal carotid artery to a branch of the external carotid system. Nevertheless, a persistent stapedial artery is seen in 0.2-4.8 per thousand of human adults. This persistence is usually asymptomatic but can sometimes cause pulsatile tinnitus or conductive hearing loss. Despite the risk of facial palsy, hearing loss and even hemiplegia argued by several authors, some surgeons have succeeded in coagulation without side effects. Reviewing the literature, we seek to enlighten the actual knowledge about the persistent stapedial artery to evaluate the risk to coagulate it. Embryologic studies explain the four types of persistent stapedial arteries: the hyoido-stapedial artery, the pharyngo-stapedial artery, the pharyngo-hyo-stapedial artery and aberrant internal carotid with persistent stapedial artery. Phylogenetic studies show that the stapedial artery persists in adulthood in many vertebrates. Its disappearance is therefore either a random effect or an adaptative convergence. This adaptation could be partially linked to the negative allometry of the stapes. Practically, the risk to coagulate a stapedial artery seems limited thanks to anastomoses, for example with the stylomastoid artery. The risk of hemiplegia reported is in fact an extrapolation of variation in rats' embryos. A persistent stapedial artery can therefore reasonably be coagulated, with special attention to the facial nerve, because the facial canal is always dehiscent where the artery penetrates.
Singular neurectomy (posterior ampullary nerve transsection) and posterior semicircular canal occlusion are the 2 specific techniques used in intractable BPPV surgery. The numbers of operated cases are 342 and 97, respectively. These small numbers indicate that the procedures are difficult and risk compromising hearing and that a very small population of patients require surgical treatment of BPPV. The operated cases have been decreasing since the early 1990s because of improved management in BPPV. This article summarizes the techniques and their results and proposes a currently recommended practice of surgical therapy in BPPV as well as new insights into intractable BPPVs' physiopathology.
Xenobiotic metabolizing enzymes and other proteins, including odorant-binding proteins located in the nasal epithelium and mucus, participate in a series of processes modulating the concentration of odorants in the environment of olfactory receptors and finely impact odor perception. These enzymes and transporters are thought to participate in odorant degradation or transport. Odorant biotransformation results in (i) changes in the odorant quantity up to their clearance and the termination of signalling and (ii) the formation of new odorant stimuli (metabolites). Enzymes, such as cytochrome P450 and glutathione transferases (GSTs), have been proposed to participate in odorant clearance in insects and mammals as odorant metabolizing enzymes. This study aims to explore the function of GSTs in human olfaction. Using immunohistochemical methods, GSTs were found to be localized in human tissues surrounding the olfactory epithelium. Then, the activity of two members of the GST family towards odorants was measured using heterologously expressed enzymes. The interactions/reactions with odorants were further characterized using a combination of enzymatic techniques. Furthermore, the structure of the complex between human GSTA1 and the glutathione conjugate of an odorant was determined by X-ray crystallography. Our results strongly suggest the role of human GSTs in the modulation of odorant availability to olfactory receptors in the peripheral olfactory process.
This morphometric study allowed us to define the vascularization and the anatomical variations of RGOA and GO. This may lead to improvement of applications in surgery and decrease complications.
Sirenomelia or "mermaid syndrome" is a rare congenital anomaly known since antiquity. This congenital anomaly is defined as a polymalformative syndrome that associates major muscle and skeleton abnormalities (unique lower limbs) with visceral abnormalities (unilateral or bilateral renal agenesis, anomalies of the abdominal vascularisation). This phenotype, typical of sirenomelia syndrome, may be more or less severe. The pathogenic mechanisms of this syndrome are still debated and its etiology remains unknown. We report here a new type of sirenomelia that we observed in a fetus belonging to the collection of the Department of Anatomy of Reims, which led us to perform a comprehensive review of the literature on the subject: this type has never been reported and cannot be classified according to the Stocker and Heifetz classification. Moreover, this case also presents a VACTERL association with Thomas syndrome.
Those 27-month results demonstrate the validity of our UNHS program, which relies on the cooperation with maternities, an easy protocol and a strong follow-up procedure.
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