**1. Introduction**

As defined by the World Health Organization (WHO), osteoporosis is present when BMD is 2.5 SD or more below the average value for young healthy women (a T-score of <−2.5 SD). A second, higher threshold describes "low bone mass" or osteopenia as a T-score that lies between −1 and − 2.5 SD. Osteopenia is a precursor stage of osteoporosis. The difference between the patient's BMD and mean BMD of young females aged in the range of 20–29 years (divided by the standard deviation (SD) of the reference population) yields the T-score; comparing the BMD of a particular age, sex and ethnicity-matched adult reference population is called the Z-score. Treatment plans are linked to specific T-score values [1]. The problem is found in classification, diagnosis, and treatment of osteoporosis [1–5]. Searches are underway for solutions. Among the research directions is the genetic search for solutions to the problems facing DEXA in particular in assessing the condition of the bone and the subsequent selection of the appropriate treatment plan [6–11]. Among the genes selected for study are the COL1A2 gene and LRP5 gene. The COL1A2 gene is chosen because it expresses the collagen protein responsible

for bone elasticity by 90% [1]. DEXA completely ignores bone elasticity, as it only measures bone mineral density, which represents only the strength of the bone, not its elasticity. In order to achieve perfect bone, a balance must be achieved between the strength and flexibility of the bone. This is one of the biggest evidences of the inadequacy of DEXA to assess osteoporosis [9]. The COL1A2rs72658152 (located at 7q21.3,G > A1981,OMIM:120160) is chosen specifically because it is inherited in a dominant manner [12, 13] and has proven pathogenicity for postmenopausal osteoporosis. There is no idea how widespread it is in most societies [14]. On the other hand, the LRP5gene is chosen for its relationship to the formation of cortical bone [15], which forms the majority of the femur bone [1], meaning that LRP5 is a very important protein in the pathway for bone formation and construction in the femur region [16, 17] (femur region is one of the DEXA measurement sites, and therefore, it is possible to compare the DEXA results with the genetic results). The LRP5rs121908669 (located at 11q13.2, G > C 511, OMIM: 603506) is chosen because it is inherited predominantly [17], and it has not been genotyped nor in any research worldwide. It is proven to be a form of osteopetrosis. There is no idea how widespread it is in most societies [14]. The spread of applications such as FRAX can be seen as an attempt to solve the problems facing DEXA [11].
