First case of Roma ethnic origin with Andermann syndrome: A novel frameshift mutation in exon 20 of SLC12A6 gene

Am J Med Genet A. 2019 Jun;179(6):1020-1024. doi: 10.1002/ajmg.a.61110. Epub 2019 Mar 13.

Abstract

Andermann syndrome (AS) is caused by mutation of SLC12A6 gene. It comprises severe progressive sensory and motor neuropathy with early onset, varying degree of agenesis of corpus callosum (ACC) and mental retardation. AS occurs occasionally among population outside the northeastern Quebec-Saguenay-Lac- St-Jean and Charlevoix regions, inhabited by French Canadians. None of the described patients were of Roma ethnic origin. We present an 8-month-old infant of Roma ethnic origin with AS, caused by a novel frame shift mutation c.2604delT,p.(Asp868GlufsTer11) in exon 20 of SLC12A6 gene. Our case presented with several atypical findings: clinical presentation resembling "spinal muscular atrophy plus" syndrome; tongue fasciculations, which are not reported in the literature; early contractures of the wrists; normal motor action potentials and preserved sensory action potentials. Our patient is the first of Roma origin from nonconsanguineous parents, which suggests that this mutation might be widespread in the Roma population, although screening for this mutation in 140 alleles from Roma individuals originating from the same geographic region did not reveal further carriers, implying the mutation is rare. We recommend that Roma patients presenting with the clinical phenotype of AS should be tested for this mutation primarily.

Keywords: SLC12A6 gene; Andermann syndrome; Roma population; agenesis of corpus callosum; hereditary neuropathy.

Publication types

  • Case Reports

MeSH terms

  • Agenesis of Corpus Callosum / diagnosis*
  • Agenesis of Corpus Callosum / genetics*
  • Alleles
  • Electromyography
  • Ethnicity / genetics*
  • Exons*
  • Follow-Up Studies
  • Frameshift Mutation*
  • Genetic Association Studies
  • Genetic Predisposition to Disease
  • Genotype
  • Humans
  • Infant
  • Magnetic Resonance Imaging
  • Male
  • Neural Conduction
  • Peripheral Nervous System Diseases / diagnosis*
  • Peripheral Nervous System Diseases / genetics*
  • Phenotype
  • Quebec
  • Symporters / genetics*

Substances

  • SLC12A6 protein, human
  • Symporters

Supplementary concepts

  • Corpus callosum agenesis neuronopathy