A Novel Homozygous ACBD5 Variant in an Emerging Peroxisomal Disorder Presenting with Retinal Dystrophy and a Review of the Literature.

Introduction:Acyl-CoA binding domain containing 5 (ACBD5) deficiency is a newly defined inborn peroxisomal disorder with only 7 patients reported to date. Herein, we report a patient with ACBD5 deficiency who was diagnosed after a complicated diagnostic process. Case Presentation:A 6-year-old male patient was admitted with complaints of neuromotor regression and visual disturbances. He had spastic paraparesis dominated with axial hypotonic posturing and horizontal nystagmus. His very-long-chain fatty acid levels were within normal ranges with a slightly elevated C26:0/C22:0 ratio. Brain magnetic resonance imaging revealed white matter involvement. Clinical exome sequencing displayed a novel homozygous intronic splice site variant (c.936 + 2T>G) in the ACBD5 (NM_145698.5) gene. Conclusion:With this report, a novel variant in ACBD5 deficiency was described. Macular dystrophy was demonstrated with optical coherence tomography imaging for the first time in the literature in ACBD5 deficiency. In order to contribute to the knowledge about the clinical, biochemical, and genetic spectrum of ACBD5 deficiency, new patients need to be defined.