Early diagnosis and treatment by newborn screening (NBS) or family history is associated with improved visual outcomes for long‐chain 3‐hydroxyacylCoA dehydrogenase deficiency (LCHADD) chorioretinopathy

Abstract

Long chain 3‐hydroxyacyl‐CoA dehydrogenase (LCHADD) is the only fatty acid oxidation disorder to develop a progressive chorioretinopathy resulting in vision loss; newborn screening (NBS) for this disorder began in the United States around 2004. We compared visual outcomes among 40 participants with LCHADD or trifunctional protein deficiency diagnosed symptomatically to those who were diagnosed via NBS or a family history. Participants completed ophthalmologic testing including measures of visual acuity, electroretinograms (ERG), fundal imaging, contrast sensitivity, and visual fields. Records were reviewed to document medical and treatment history. Twelve participants presented symptomatically with hypoglycemia, failure to thrive, liver dysfunction, cardiac arrest, or rhabdomyolysis. Twenty eight were diagnosed by NBS or due to a family history of LCHADD. Participants diagnosed symptomatically were older but had similar percent males and genotypes as those diagnosed by NBS. Treatment consisted of fasting avoidance, dietary long‐chain fat restriction, MCT, C7, and/or carnitine supplementation. Visual acuity, rod‐ and cone‐driven amplitudes on ERG, contrast sensitivity scores, and visual fields were all significantly worse among participants diagnosed symptomatically compared to NBS. In mixed‐effects models, both age and presentation (symptomatic vs. NBS) were significant independent factors associated with visual outcomes. This suggests that visual outcomes were improved by NBS, but there was still lower visual function with advancing age in both groups. Early diagnosis and treatment by NBS is associated with improved visual outcomes and retinal function compared to participants who presented symptomatically. Despite the impact of early intervention, chorioretinopathy was greater with advancing age, highlighting the need for novel treatments.

The LCHADD Mouse Model Recapitulates Early-Stage Chorioretinopathy in LCHADD Patients

“…Although treatment can delay or slow progression, the diet does not prevent the chorioretinopathy, highlighting a need for a retina-specific treatment for LCHADD chorioretinopathy. [17][18][19][20] Unfortunately, research into LCHADD chorioretinopathy has been limited due to the lack of model organisms. To address this problem, we recently reported a novel LCHADD mouse model that is homozygous for the c.G1528C variant in Hadha and recapitulated many of the human phenotypes.…”

“…Although treatment can delay or slow progression, the diet does not prevent the chorioretinopathy, highlighting a need for a retina-specific treatment for LCHADD chorioretinopathy. 17 – 20 …”