Comparison of Makorin Ring Finger Protein 3 Levels Between Obese and Normal Weight Patients with Central Precocious Puberty

OBJECTIVE: Genetic studies of familial central precocious puberty (CPP) have suggested that makorin ring finger protein 3 (MKRN3) is the primary inhibitor of gonadotropin-releasing hormone secretion. Obesity in girls can cause early puberty by affecting the hypothalamic-pituitary-gonadal axis. This study evaluated serum MKRN3 levels of patients with CPP and its relationship with body mass index (BMI). METHODS: The study included 92 CPP and 86 prepubertal healthy controls (HC) aged 6-10 years. The CPP and HC groups were divided into obese and non-obese subgroups to evaluate whether BMI affects MKRN3. Patients’ presenting complaints, chronological age, height age, bone age, Tanner stage, standard deviation scores for weight, height, and BMI, levels of follicle-stimulating hormone, luteinizing hormone, estradiol, and MKRN3, and pelvic ultrasonography findings were recorded. RESULTS: Serum MKRN3 levels were lower in the CPP group and lowest in the CPP-obese subgroup. There were significant differences in MKRN3 levels between the CPP-obese and CPP-normal weight (p=0.02), CPP-obese and HC-obese (p<0.001), and CPP-obese and HC-normal weight (p=0.03) groups. MKRN3 and BMI were negatively correlated in all cases (r=-0.326, p<0.001). CONCLUSION: The negative correlation between BMI and MKRN3, and lower MKRN3 levels in CPP-obese patients, suggests that adipose tissue has a role in the onset of puberty. More comprehensive studies are needed to determine the relationship between MKRN3 and adipose tissue.