Novel ABHD12 mutations in PHARC patients: the differential diagnosis of deaf-blindness.
OBJECTIVE
This study examines ABHD12 mutation analysis in 2 PHARC patients, originally thought to be Usher syndrome.


METHODS
The ABHD12 gene of 2 patients, who suffered from deaf-blindness and dysfunctional central and peripheral nervous systems, were sequenced.


RESULTS
We identified that both cases carried the same novel splice site mutation in the ABHD12 gene. However, 1 had epilepsy and the other had peripheral neuropathy. Based on haplotype analysis, the mutation is likely not a hot spot, but rather could be attributable to a common ancestor.


CONCLUSIONS
This study shows that PHARC has phenotypic variability, even within a family, which is consistent with previous reports. Differential diagnosis of "deaf-blindness" diseases is crucial. Confirming the presence of associated symptoms is necessary for differentiating some deaf-blindness syndromes. In addition, mutation analysis is a useful tool for confirming the diagnosis.
Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan.
Hidekane
H
Yoshimura
Department of Neurology, Aizawa Hospital, Matsumoto, Japan.
Takao
T
Hashimoto
Department of Ophthalmology, Shinshu University School of Medicine, Matsumoto, Japan.
Toshinori
T
Murata
Department of Otorhinolaryngology, Fukuoka University School of Medicine, Fukuoka, Japan.
Kunihiro
K
Fukushima
Department of Otorhinolaryngology-Head and Neck Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan.
Akiko
A
Sugaya
Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan Department of Hearing Implant Science, Shinshu University School of Medicine, Matsumoto, Japan.
Shin-Ya
SY
Nishio
Department of Otorhinolaryngology, Shinshu University School of Medicine, Matsumoto, Japan Department of Hearing Implant Science, Shinshu University School of Medicine, Matsumoto, Japan usami@shinshu-u.ac.jp.
Shin-Ichi
S
Usami
D001259:Ataxia / Q000235:genetics*; D001921:Brain / Q000473:pathology; D002386:Cataract / Q000235:genetics*; D004252:DNA Mutational Analysis; D054062:Deaf-Blind Disorders / Q000175:diagnosis / Q000235:genetics*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D008994:Monoacylglycerol Lipases / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D011115:Polyneuropathies / Q000235:genetics*; D012174:Retinitis Pigmentosa / Q000235:genetics*; D052245:Usher Syndromes / Q000235:genetics
C552558:ABHD12 protein, human; D008994:Monoacylglycerol Lipases
ABHD12; PHARC; Usher syndrome; deaf-blindness; genetics of hearing loss