A Novel ABCD1 Mutation Detected by Next Generation Sequencing in Presumed Hereditary Spastic Paraplegia: A 30-year Diagnostic Delay Caused by Misleading Biochemical Findings

J Neurol Sci. 2015 Aug 15;355(1-2):199-201. doi: 10.1016/j.jns.2015.05.031. Epub 2015 May 29.

Abstract

Objectives: To present a Greek family in which 5 male and 2 female members developed progressive spastic paraplegia. Plasma very long chain fatty acids (VLCFA) were reportedly normal at first testing in an affected male and for over 30 years the presumed diagnosis was hereditary spastic paraplegia (HSP). Targeted next generation sequencing (NGS) was used as a further diagnostic tool.

Methods: Targeted exome sequencing in the proband, followed by Sanger sequencing confirmation; mutation segregation testing in multiple family members and plasma VLCFA measurement in the proband.

Results: NGS of the proband revealed a novel frameshift mutation in ABCD1 (c.1174_1178del, p.Leu392Serfs*7), bringing an end to diagnostic uncertainty by establishing the diagnosis of adrenomyeloneuropathy (AMN), the myelopathic phenotype of X-linked adrenoleukodystrophy (ALD). The mutation segregated in all family members and the diagnosis of AMN/ALD was confirmed by plasma VLCFA measurement. Confounding factors that delayed the diagnosis are presented.

Conclusions: This report highlights the diagnostic utility of NGS in patients with undiagnosed spastic paraplegia, establishing a molecular diagnosis of AMN, allowing proper genetic counseling and management, and overcoming the diagnostic delay that can be rarely caused by false negative VLCFA analysis.

Keywords: ABCD1; Adrenomyeloneuropathy; Hereditary spastic paraplegia; Next generation sequencing; Novel mutation; X-linked adrenoleukodystrophy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily D, Member 1
  • ATP-Binding Cassette Transporters / genetics*
  • Adult
  • Aged
  • Animals
  • Family Health*
  • Female
  • Genetic Predisposition to Disease / genetics
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Spastic Paraplegia, Hereditary / genetics*
  • Young Adult

Substances

  • ABCD1 protein, human
  • ATP Binding Cassette Transporter, Subfamily D, Member 1
  • ATP-Binding Cassette Transporters