Genetic Background of Macular Telangiectasia Type 2

Macular telangiectasia type 2 (MacTel) is a slowly progressive macular disorder often diagnosed late due to the gradual onset of vision loss. Recent advances in diagnostic techniques have facilitated earlier detection, revealing MacTel is more common than initially thought. The disease is genetically complex, with multiple variants contributing incrementally to the overall risk. Familial occurrence of the disease prompted investigations of the genetic background of MacTel. In aim to raise the disease molecular milieu, a literature review of the clinical reports and publications investigating the genetic factors of MacTel was performed. To date, disease-associated variants were found in genes involved in amino acid (glycine/serine) metabolism and transport, urea cycle, lipid metabolism, and retinal vasculature and thickness. Variants in genes implicated in sphingolipid metabolism and fatty acid/steroid/retinol metabolism have been found in patients with neurological disorders who also have MacTel. Retinal metabolism involves complex biochemical processes essential for maintaining the high energy requirements of the retina. Genetic alternations can disrupt key metabolic pathways, leading to retinal cell degradation and the subsequent vision loss that characterizes several retinal disorders, including MacTel. This review article summarises genetic findings that may allow MacTel to be investigated further as an inherited retinal disorder.