Wolfram syndrome in the Japanese population; molecular analysis of WFS1 gene and characterization of clinical features

PLoS One. 2014 Sep 11;9(9):e106906. doi: 10.1371/journal.pone.0106906. eCollection 2014.

Abstract

Background: Wolfram syndrome (WFS) is a recessive neurologic and endocrinologic degenerative disorder, and is also known as DIDMOAD (Diabetes Insipidus, early-onset Diabetes Mellitus, progressive Optic Atrophy and Deafness) syndrome. Most affected individuals carry recessive mutations in the Wolfram syndrome 1 gene (WFS1). However, the phenotypic pleiomorphism, rarity and molecular complexity of this disease complicate our efforts to understand WFS. To address this limitation, we aimed to describe complications and to elucidate the contributions of WFS1 mutations to clinical manifestations in Japanese patients with WFS.

Methodology: The minimal ascertainment criterion for diagnosing WFS was having both early onset diabetes mellitus and bilateral optic atrophy. Genetic analysis for WFS1 was performed by direct sequencing.

Principal findings: Sixty-seven patients were identified nationally for a prevalence of one per 710,000, with 33 patients (49%) having all 4 components of DIDMOAD. In 40 subjects who agreed to participate in this investigation from 30 unrelated families, the earliest manifestation was DM at a median age of 8.7 years, followed by OA at a median age of 15.8 years. However, either OA or DI was the first diagnosed feature in 6 subjects. In 10, features other than DM predated OA. Twenty-seven patients (67.5%) had a broad spectrum of recessive mutations in WFS1. Two patients had mutations in only one allele. Eleven patients (27.5%) had intact WFS1 alleles. Ages at onset of both DM and OA in patients with recessive WFS1 mutations were indistinguishable from those in patients without WFS1 mutations. In the patients with predicted complete loss-of-function mutations, ages at the onsets of both DM and OA were significantly earlier than those in patients with predicted partial-loss-of function mutations.

Conclusion/significance: This study emphasizes the clinical and genetic heterogeneity in patients with WFS. Genotype-phenotype correlations may exist in patients with WFS1 mutations, as demonstrated by the disease onset.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Child
  • Diabetes Complications / genetics
  • Diabetes Complications / pathology
  • Female
  • Genetic Association Studies
  • Humans
  • Japan
  • Male
  • Membrane Proteins / genetics*
  • Mutation
  • Neuroimaging*
  • Optic Atrophy / genetics
  • Optic Atrophy / pathology
  • Pedigree
  • Wolfram Syndrome / diagnosis*
  • Wolfram Syndrome / epidemiology
  • Wolfram Syndrome / genetics*
  • Wolfram Syndrome / pathology

Substances

  • Membrane Proteins
  • wolframin protein

Grant support

This study was supported in part by a grant for intractable disease (to Y. Tanizawa) from the Ministry of Health, Labor and Welfare of Japan, Grants-in-Aid for Scientific Research (grant no. 16390096, 18390103 and 20390093 to Y. Tanizawa, 22590984 and 25461357 to K. Tanabe) from the Ministry of Education, Culture, Sports, and Science, a grant H16-genome-003 (to Y. Oka and Y. Tanizawa), and a grant from the Banyu International Science Foundation (to Y. Tanizawa and K. Tanabe). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.