An association between the sarcolemmal membrane-associated protein gene and microvascular endothelial diabetic retinopathy in patients with type 2 diabetes mellitus: A preliminary case control study Hanan Mohamed Farhan a , Mahmoud Nassar b, * , Mansour Hassan Ahmed c , Khadiga Abougabal a , Niveen Abd Elazim Taha a a Clinical & Chemical Pathology Department, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt b Medicine Department, Icahn School of Medicine at Mount Sinai / NYC Health þ Hospital / Queens, New York, USA c Ophthalmology Department, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt article info Article history: Received 24 July 2022 Received in revised form 11 October 2022 Accepted 14 October 2022 Keywords: Sarcolemmal membrane-associated protein SLMAP rs17058639 C >T gene polymorphism Endothelial dysfunction Diabetic retinopathy SLMAP protein abstract Background and aims: Diabetic retinopathy (DR) is one of the most common microvascular diabetic complications. Sarcolemmal membrane-associated protein (SLMAP) has been implicated in playing a role in microvascular endothelial dysfunction. This study aimed to assess the significance of SLMAP rs17058639C > T gene polymorphism among patients with type 2 diabetes mellitus (T2DM) and its relevance to microvascular endothelial diabetic retinopathy. Methods: We conducted this case-control study on 100 individuals divided into 60 participants with T2DM and 40 healthy controls. Patients with T2D were stratified into two groups: 40 patients with DR and 20 patients with diabetic non-retinopathy (DNR). Patients with T2DM were compared with age- and sex-matched healthy controls. Fundus examinations were conducted to detect microvascular endothelial changes. The polymorphism of SLMAP rs17058639C > T gene was identified by real-time polymerase chain reaction (RT-PCR) TaqMan allelic discrimination. Results: Patients with DR have significantly increased glycated hemoglobin (HbA1c) compared to pa- tients with DNR (P < 0.001). There was no statistically significant difference found between diabetic and control groups regarding the frequency of SLMAP rs17058639C > T genotypes. The homozygous CC ge- notype was the most common variant among patients with DR; however, the results did not reach statistical significance. Conclusions: Diabetic retinopathy is correlated with poor glycemic control, and SLMAP rs17058639C > T polymorphism was associated with microvascular endothelial DR in patients with T2DM, although further studies with a large sample size are needed to confirm our findings. © 2022 Diabetes India. Published by Elsevier Ltd. All rights reserved. 1. Introduction Diabetes mellitus (DM) leads to macrovascular and microvas- cular complications, including nephropathy, retinopathy, and neuropathy [1 ,2]. Diabetic retinopathy is the most common microvascular complication in diabetes and is considered one of the leading causes of blindness among the adult population [3]. Worldwide, diabetic retinopathy affects 27% of patients with dia- betes, with the highest prevalence reported in the Western Pacific region (36.2%), followed by the Middle East and North Africa with 33.8%, Europe with 20.6%, and Asia with 12.5% [4]. Sarcolemmal membrane-associated protein (SLMAP) belongs to the superfamily of tail-anchored membrane proteins [5]. SLMAP is a component of the endoplasmic reticulum/sarcoplasmic reticulum, mitochondria, cell membrane, and nuclear envelope [6]. The SLMAP * Corresponding author. Medicine Department, Icahn School of Medicine at Mount Sinai / NYC Health þ Hospitals, Queens, 82-68 164th St. Jamaica, New York, 11432, USA. E-mail addresses: hananmohamedfarhan@gmail.com (H. Mohamed Farhan), Dr. Nassar@aucegypt.edu (M. Nassar), president@bsu.edu.eg (M. Hassan Ahmed), khadiga20047@hotmail.com (K. Abougabal), dr.ahmed_cts@hotmail.com (N. Abd Elazim Taha). Contents lists available at ScienceDirect Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx https://doi.org/10.1016/j.dsx.2022.102653 1871-4021/© 2022 Diabetes India. Published by Elsevier Ltd. All rights reserved. Diabetes & Metabolic Syndrome: Clinical Research & Reviews 16 (2022) 102653