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Outcomes of clinical examination and genetic testing of 500 individuals with hearing loss evaluated through a genetics of hearing loss clinic
Author(s) -
Yaeger Dinah,
McCallum Jennifer,
Lewis Kathy,
Soslow Lisa,
Shah Udayan,
Potsic William,
Stolle Catherine,
Krantz Ian D.
Publication year - 2006
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.31179
Subject(s) - hearing loss , medicine , genetic testing , etiology , genetic counseling , medical genetics , congenital hearing loss , pediatrics , sensorineural hearing loss , audiology , genetics , gene , biology
Abstract Hearing loss (HL) occurs in approximately 2 out of every 1,000 births and is genetic in origin in approximately 50% of cases. This high incidence coupled with the increasing number of genes implicated in HL and the trend toward universal newborn screening led to the establishment of the Genetics of Hearing Loss Clinic at The Children's Hospital of Philadelphia to manage the diagnosis, genetic screening, and counseling of families with an affected child. To date 500 individuals have been evaluated from 1999 to 2004. To determine the cause of their HL and screen for syndromic forms of HL, individuals were offered a panel of tests. Depending on the type and severity of the HL, recommendations included GJB2 mutation analysis, renal and thyroid function studies, a CT scan of the temporal bones, an ophthalmology evaluation, an EKG, and, at times, additional genetic tests. Of the 500 patients evaluated 70 (14%) had a syndromic etiology for their HL. Twenty‐eight different syndromic etiologies were identified. Enlarged vestibular aqueducts (EVAs) and/or Mondini malformations were seen in 18% of individuals with HL who had a CT or MRI of the temporal bones. Genetic testing of the GJB2 gene was completed for 310 of the 377 patients with bilateral sensorineural HL (82.2%). Nineteen different variants were identified in the GJB2 gene. Through GJB2 mutational analysis, clinical examination, and laboratory testing, a definitive etiologic diagnosis was established in 110/500 (22%) of patients. © 2006 Wiley‐Liss, Inc.