Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency and progressive retinopathy: one case report followed by ERGs, VEPs, EOG over a 17-year period

Doc Ophthalmol. 2021 Jun;142(3):371-380. doi: 10.1007/s10633-020-09802-y. Epub 2021 Jan 4.

Abstract

Background: LCHAD (long-chain 3-hydroxyacyl-CoA dehydrogenase) deficiency is a rare genetic disorder of mitochondrial long-chain fatty acid oxidation inherited as a recessive trait. Affected patients can present with hypoglycaemia, rhabdomyolysis and cardiomyopathy. About half of the patients may suffer from retinopathy.

Case report: A 19-year-old girl was diagnosed as suffering from LCHAD deficiency with recurrent rhabdomyolysis episodes at the age of 7 months by an inaugural coma with hypoglycaemia and hepatomegaly. Appropriate dietary management with carnitine supplementation was initiated. Retinopathy was diagnosed at age two. Ophthalmological assessments including visual acuity, visual field, OCT, flash ERGs, P-ERG, flash VEPs and EOG recordings were conducted over a 17-year period.

Results: Visual acuity was decreased. Fundi showed a progressive retinopathy and chorioretinopathy. Photophobia was noticed 2 years before the decrease in photopic-ERG amplitude with normal scotopic-ERGs. Scotopic-ERG amplitude decreased 10 years after the decrease in photopic-ERG amplitude. No EOG light rise was observed. Flash VEPs remained normal. These results suggest that the cone system dysfunction occurs largely prior to the rod system dysfunction with a relative preservation of the macula function.

Comments: This dysfunction of cones prior to the dysfunction of rods was not reported previously. This could be related to mitochondrial energy failure in cones as cones are greater consumers of ATP than rods. This hypothesis needs to be further confirmed as other long-chain fatty oxidation defective patients (VLCAD and CPT2 deficiencies) do not exhibit retinopathy.

Keywords: Cone ATP deficiency; LCHAD-deficiency; Photopic-ERG deficiency preceding scotopic-ERG; Retinopathy.

Publication types

  • Case Reports

MeSH terms

  • 3-Hydroxyacyl CoA Dehydrogenases / genetics
  • 3-Hydroxyacyl-CoA Dehydrogenase
  • Adult
  • Cardiomyopathies*
  • Electrooculography
  • Electroretinography
  • Female
  • Humans
  • Infant
  • Lipid Metabolism, Inborn Errors
  • Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase
  • Mitochondrial Myopathies
  • Mitochondrial Trifunctional Protein / deficiency
  • Nervous System Diseases
  • Retinal Diseases* / diagnosis
  • Rhabdomyolysis*
  • Transcriptional Regulator ERG
  • Young Adult

Substances

  • ERG protein, human
  • Transcriptional Regulator ERG
  • 3-Hydroxyacyl CoA Dehydrogenases
  • Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase
  • 3-Hydroxyacyl-CoA Dehydrogenase
  • Mitochondrial Trifunctional Protein

Supplementary concepts

  • Trifunctional Protein Deficiency With Myopathy And Neuropathy