Deficient auditory interhemispheric transfer in patients with PAX6 mutations.
PAX6 mutations are associated with absence/hypoplasia of the anterior commissure and reduction in the callosal area in humans. Both of these structures contain auditory interhemispheric fibers. The aim of this study was to characterize central auditory function in patients with a PAX6 mutation. We conducted central auditory tests (dichotic speech, pattern, and gaps in noise tests) on eight subjects with a PAX6 mutation and eight age- and sex-matched controls. Brain magnetic resonance imaging showed absent/hypoplastic anterior commissure in six and a hypoplastic corpus callosum in three PAX6 subjects. The control group gave normal central auditory tests results. All the PAX6 subjects gave abnormal results in at least two tests that require interhemispheric transfer, and all but one gave normal results in a test not requiring interhemispheric transfer. The left ear scores in the dichotic speech tests was significantly lower in the PAX6 than in the control group. These results are consistent with deficient auditory interhemispheric transfer in patients with a PAX6 mutation, which may be attributable to structural and/or functional abnormalities of the anterior commisure and corpus callosum, although the exact contribution of these two formations to our findings remains unclear. Our unique findings broaden the possible functions of PAX6 to include neurodevelopmental roles in higher order auditory processing.
Bamiou
Doris-Eva
DE
Neuro-otology Department, National Hospital for Neurology and Neurosurgery, London, United Kingdom. doris-eva.bamiou@uclh.org
Musiek
Frank E
FE
Sisodiya
Sanjay M
SM
Free
Samantha L
SL
Davies
Rosalyn A
RA
Moore
Anthony
A
van Heyningen
Veronica
V
Luxon
Linda M
LM
D000328:Adult; D061085:Agenesis of Corpus Callosum; D001307:Auditory Perception / Q000502:physiology; D001927:Brain Diseases / Q000235:genetics* / Q000503:physiopathology*; D016022:Case-Control Studies; D003337:Corpus Callosum / Q000502:physiology; D005136:Eye Proteins; D005260:Female; D007839:Functional Laterality; D006320:Hearing Tests / Q000379:methods; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009154:Mutation; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins
D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins