Novel ABHD12 mutations in PHARC patients: the differential diagnosis of deaf-blindness

Ann Otol Rhinol Laryngol. 2015 May:124 Suppl 1:77S-83S. doi: 10.1177/0003489415574513. Epub 2015 Mar 5.

Abstract

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.

Conclusion: 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.

Keywords: ABHD12; PHARC; Usher syndrome; deaf-blindness; genetics of hearing loss.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ataxia / genetics*
  • Brain / pathology
  • Cataract / genetics*
  • DNA Mutational Analysis
  • Deaf-Blind Disorders / diagnosis
  • Deaf-Blind Disorders / genetics*
  • Diagnosis, Differential
  • Humans
  • Male
  • Middle Aged
  • Monoacylglycerol Lipases / genetics*
  • Pedigree
  • Phenotype
  • Polyneuropathies / genetics*
  • Retinitis Pigmentosa / genetics*
  • Usher Syndromes / genetics

Substances

  • ABHD12 protein, human
  • Monoacylglycerol Lipases

Supplementary concepts

  • Polyneuropathy, Hearing Loss, Ataxia, Retinitis Pigmentosa, And Cataract