Association Study of <i>SLC6A4</i> (5-HTTLPR) Polymorphism and Its Promoter Methylation with Rehabilitation Outcome in Patients with Subacute Stroke

• Main Authors: Massimo Santoro, Mariacristina Siotto, Marco Germanotta, Alessia Mastrorosa, Dionysia Papadopoulou, Irene Aprile
• Format: Article
• Language: English
• Published: MDPI AG 2021-04-01
• Series: Genes
• Subjects: <i>SLC6A4</i>; 5-HTTLPR polymorphism; methylation; stroke; rehabilitation
• Online Access: https://www.mdpi.com/2073-4425/12/4/579

Recently it has been suggested that <i>serotonin transporter</i> (<i>SLC6A4</i>) and its 5HTTLPR polymorphism could be involved in post stroke recovery. Here, we characterized the methylation profile of two different CpG islands within the <i>SLC6A4</i> promoter region in the whole blood of 50 patients with subacute stroke before and after a six-week rehabilitation treatment. These patients were genotyped for 5HTTLPR polymorphism identifying patients on the basis of short (S) and L (L) alleles: 17 patients LL, 22 patients LS and 11 patients SS. At baseline, all CpG sites for both CpG islands displayed a heterogeneous methylation percentage that were not influenced by the different genotypes. After rehabilitation, we found a significant variation in the methylation levels (increase/decrease) in the specific CpG sites of both CpG islands. The statistical analysis showed a significant relationship between the LL, LS and SS alleles and the outcome of the rehabilitation intervention (<i>χ</i>² (2,50) = 6.395, <i>p</i> = 0.041). Specifically, we found a significant difference between patients with or without a favorable outcome in the LL (11.1% with a favorable outcome) and in the SS (54.4% with a favorable outcome) groups. Our data suggest that 5-HTTLPR polymorphisms and <i>SLC6A4</i> promoter methylation may be employed as a non-invasive biological marker of recovery in patients with stroke undergoing rehabilitation.