[Usher type I syndrome in children: genotype/phenotype correlation and cochlear implant benefits].
OBJECTIVE
To assess the benefit of cochlear implant in children presenting an Usher type 1 syndrome (speech understanding, speech production intelligibility, academic performance) and to search any correlation between the phenotype and the genotype in this population.


METHODS
Retrospective case series analysis about 13 implanted Usher type I children. Cochlear implantation was performed from 1995 to 2005. Our population was divided in three groups: group 1 (implantation between 1 and 3 years of age); group 2 (implantation between 4 and 7 years of age) and group 3 (implantation between 14 and 17 years of age). Postoperative speech perception, speech production intelligibility and education settings were evaluated.


RESULTS
Molecular genetic analysis was performed in 11 patients and pathogenic mutations were identified in all cases: (mutation in myosin 7A gene in 5 cases; mutation in cadherin 23 gene in 6 cases). Four new mutations 2 in the MYO7A gene and 2 in the CDH23 gene never reported before were found. Walking delay and hearing level were not statistically correlated with the genotype abnormalities found. The speech discrimination skills, the speech production intelligibility and the academic performance were better in the group 1 children than the group 2 children after cochlear implantation. All the children of group 1 but one were in mainstreaming education. Specific language impairment was identified in two children of group 1. The group 3 children could not achieve open-set perceptive tasks after implantation--only closed-set word test can be done and their speech production remained unintelligible after cochlear implantation.


CONCLUSIONS
Molecular analysis of Usher type I syndrome can ascertain the diagnosis in spite of the genetic heterogeneity. In this study, clinical symptoms weren't correlated with genotypic mutations. Speech discrimination skills, speech production quality, and academic performance were correlated with the age at implant.
Blanchet
C
C
CHU de Montpellier, Centre National de Référence Affections Sensorielles et Génétiques, Oto-rhino-laryngologie, 80 avenue Augustin Fliche, 34295 Montpellier 5, France.
Roux
A F
AF
Hamel
C
C
Ben Salah
S
S
Artières
F
F
Faugère
V
V
Uziel
A
A
Mondain
M
M
D000124:Achievement; D000293:Adolescent; D000367:Age Factors; D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D004398:Dyneins / Q000235:genetics; D005500:Follow-Up Studies; D018740:Genetic Heterogeneity; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000601:surgery; D006801:Humans; D007223:Infant; D007805:Language Development Disorders / Q000209:etiology; D008282:Mainstreaming, Education; D009154:Mutation / Q000235:genetics; D000081412:Myosin VIIa; D009218:Myosins / Q000235:genetics; D010641:Phenotype; D012189:Retrospective Studies; D013065:Speech Intelligibility / Q000502:physiology; D013067:Speech Perception / Q000502:physiology; D016896:Treatment Outcome; D052245:Usher Syndromes / Q000235:genetics* / Q000503:physiopathology / Q000601:surgery
C442480:CDH23 protein, human; D000070585:Cadherin Related Proteins; D015820:Cadherins; C000631455:MYO7A protein, human; D000081412:Myosin VIIa; D009218:Myosins; D004398:Dyneins