1,721,111 research outputs found
Connexin26 deafness is not always congenital
No full textOBJECTIVE:
Hearing loss associated with mutations of the GJB2, the gene encoding Connexin 26 (Cx26), is described as a prelingual, bilateral, prevalently stable sensorineural defect ranging in severity from mild to profound. Despite many clinical studies, there is still a limited knowledge about the severity of Cx26 hearing loss at birth, in the postnatal period or in early infancy; some authors have reported about a possible variable age of onset. The aim of this work was to investigate the characteristics of Cx26 hearing loss and test the hypothesis of a postnatal sudden and severe deterioration of the hearing capacity in cases with uncertain age at onset.
METHODS:
We have studied 79 children with molecularly documented biallelic Cx26 hearing loss by evaluating longitudinal audiometric characteristics and the results of a questionnaire administered to the parents, regarding the auditory behavior of their children at 3 and 6 months of age.
RESULTS:
More than 50% of children with profound hearing loss were described as having normal auditory behavior at three months of age, and at least 20% of these children were consistently reported by the parents to maintain normal auditory development up to 6 months of age. None of the studied children showed significant progression in hearing loss from the time of diagnosis through their last follow-up. In a few cases these reports were supported by objective audiometric evaluations.
CONCLUSIONS:
Based on these data, we hypothesize that Cx26 profound hearing loss may be not always congenital, with the possibility of an early window of "functional time" before the final defect is established. The hypothesis of an early auditory input makes timing of detection and intervention critical to minimize the deleterious effects of a functional deprivation. In a near future, the combination of genetic testing with universal neonatal hearing screening and audiological surveillance will provide invaluable information about the natural history of the most frequent sensory defect in infancy and will consequently allow to maximize the quality of intervention
Mutazioni DFNB1 e Ipoacusia Neurosensoriale non Sindromica: Genetica e Caratteristiche Cliniche
No full textL’ipoacusia è il più frequente fra i difetti neurosensoriali nell’uomo; l’impatto di questo deficit funzionale è tanto maggiore quanto più severa la perdita uditiva e quanto più precocemente questa si instaura. Un’ipoacusia severa o profonda presente alla nascita, se non diagnosticata in epoca molto precoce, può seriamente compromettere l’acquisizione del linguaggio e tradursi in un handicap cronico che nonostante le moderne tecniche riabilitative è spesso di difficile gestione. Questo costituisce un problema di largo impatto sociale, se si considera una frequenza di 1-2 bambini sordi su mille nati.
Un origine genetica è probabilmente alla base del difetto uditivo in più della metà di tutti i casi di ipoacusia congenita o comunque preverbale. Esistono almeno 300 sindromi note associate ad ipoacusia, ma le forme in assoluto più frequenti sono le ipoacusie isolate, quelle nelle quali il deficit uditivo è l’unica caratteristica clinica riscontrabile. Queste rappresentano almeno il 70% di tutte le forme ereditarie e vengono trasmesse prevalentemente come autosomiche recessive. Grandissima è l’eterogeneità genetica nell’ambito dell’ipoacusia, attualmente sono noti almeno 75 loci per altrettante forme di ipoacusia ereditaria non sindromica e 36 “geni-malattia” sono stati identificati
Silhouette: Elena Lucrezia Cornaro Piscopia (1646-1684), the First University Alumna in the World
No full textOf f i c i a l document s t e s t i fy tha t El ena Luc r e z i a
Cornaro Piscopia was the first woman in the world to
achieve a university degree. The date was Saturday,
25 June 1678; the University was the Studium of Padua,
Italy; the degree was Doctor of Philosophy. These facts
were established by extensive research among all the
universities of the world by the University of Padua in
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Polycythemia vera and high serum erythropoietin in young patients: occurrence of VHL mutation
No full textRetinal capillary hemangioma in the von Hippel-Lindau disease. Natural history, clinical signs and therapeutic management of ocular manifestations.
No full textMolecular diagnosis of inherited diseases
No full textThe importance of the interaction between basic science and clinical practice has long been known but it has become even more evident in the past few decades with the impressive rate of development in the field of molecular genetics. This short article reviews molecular diagnosis of two different diseases for which scientific progress has immediately been translated into a dramatic improvement of the quality of medical care: the Fragile X Syndrome, paradigm of the new mutational mechanism of the unstable triplet repeats, and von Hippel-Lindau disease, a recent acquisition in the growing number of familial cancer syndromes
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