Is leptin receptor gene (Gln223Arg) polymorphism associated with disease susceptibility and severity in patients of primary knee osteoarthritis?

Aim of the work: A significant role of Leptin receptor (LEPR) is documented in inflammation, body weight homeostasis and maintenance of cartilage. This study was conducted to detect the existence of genetic association between Knee osteoarthritis (KOA) susceptibility and severity; and LEPR (Gln223Arg) single nucleotide polymorphism (SNP). Patients and methods: 73 primary KOA patients and 73 matched healthy controls were studied. Kellgren Laurence (K/L) radiographic grading system, Western Ontario and McMaster Universities Arthritis Index (WOMAC) score and Visual Analogue Scale (VAS) were used to assess the severity of KOA. LEPR Gln223Arg SNP (rs1137101) was genotyped in KOA patients and controls using polymerase chain reaction-restriction fragment length polymorphism (PCR -RFLP) technique and verified by direct DNA sequencing. Results: In the current study, a significant genetic association was found between KOA patients carrying the AA genotype of LEPR and the extent of radiological severity (p < 0.044). In addition, a significant difference was detected within the patients between Body Mass Index (BMI) and the SNP. Patients carrying the wild type (GG) genotype showed lower body mass index (BMI) in comparison to patients carrying the heterozygous (AG) genotype and the mutant (AA) genotype (p < 0.032). However, no direct genetic association was detected between the SNP and KOA. Conclusion: Leptin receptor gene (Gln223Arg) SNP might be associated with severity of KOA. There is a significant genetic association between the SNP and BMI hence, LEPR SNP might be indirectly associated with the incidence of KOA. Furthermore, the SNP is not directly associated with KOA susceptibility in the Egyptian population. Publishing services provided by Elsevier B.V. on behalf of Egyptian Society of Rheumatic Diseases.