The case group was made of 50 patients, 24 women (48%) and 26 men (52%) with several clinical symptoms suggestive of LDD and the condition confirmed by MRI.

The control group was made of 44 healthy volunteers.

Genotype analysis of interleukin-1β variation was analyzed with Real-Time PCR (polymerase chain reaction) using Applied bioscience 7500 Fast-Real Time PCR machine (Applied Biosystem, Foster City, California, USA). For this analysis, we use Taq primer assay which had rs number 1143627 (Thermo Fisher Scientific, Waltham, California, USA). Reverse and forward primer sequences were used defining used for possible mutations in target variations

Visual Analog Scale (VAS) was used to assess the pain severity of the patients. According to VAS, for pain intensity, it is generally rated as "no pain" 0 points and "moderate pain"5, worst pain imaginable" as 10 points (100 mm scale). They were asked to mark their average pain levels by considering one week. The pain level was questioned separately during resting and activity.

The functional level assessment was evaluated using the Oswestry Disability Index (ODI). This scale is preferred to measure the performance of the activities necessary for daily living and to define their limitations. In this scale, consist of 10 sections are included about pain level, inactivity daily living, heavy lifting, walking, sitting, standing, sleeping, sexual life, social life and travelling. There are 6 options in each question, and the patient is asked to choose the expression of his condition.

Physiotherapist will measure the Range of Motion of the lumbar spine by using digital goniometer

Physiotherapist will measure. The posterior interval between both spina iliaca was marked for measurement. After determining 10 cm above and 5 cm below the marked area, the patient was asked to perform trunk flexion while standing. The difference between the initial value and is noted in cm. The difference of 0-5 cm in the test shows that the flexion flexibility decreases, and the difference over 10 cm shows that the flexibility increases. Values between 5-10 cm are considered normal.

Lumbar sagittal Magnetic Resonance Imaging (MRI) was used for the analysis of disc degeneration, and herniation and sections of 5 mm thick were taken. T2-weighted MR examinations of all cases included in the study, independently by a radiologist who is blind to the clinical condition of the cases it was evaluated. Disc degeneration graded according to Pfirrmann's grading. For each case, all lumbar discs were scored individually (L1-2, L2-3, L3-4, L45, L5-S1) total score was calculated.