Leptin gene tetranucleotide repeat polymorphism in obese individuals in Egypt

Area of Science:

• Genetics
• Metabolic Disorders
• Human Physiology

Background:

• Leptin, a peptide hormone from adipose tissue, plays a crucial role in regulating body weight.
• Genetic variations, such as mutations in the leptin gene, have been associated with severe obesity.
• Understanding the genetic underpinnings of obesity is vital for developing targeted interventions.

Purpose of the Study:

• To investigate the association between the tetranucleotide repeat (TTTC)n polymorphism in the 3' UTR of the leptin gene and obesity in an Egyptian population.
• To compare allele frequencies and genotype distributions between obese individuals and healthy controls.
• To explore potential differences in this association between simple obesity and obesity with metabolic syndrome.

Main Methods:

• The study included 120 obese Egyptian subjects (57 with metabolic syndrome, 63 with simple obesity) and 83 healthy controls.
• Key anthropometric measures, including Body Mass Index (BMI) and Waist-Hip Ratio (WHR), were assessed.
• Leptin gene (TTTC)n polymorphism in the 3' UTR was characterized using Polymerase Chain Reaction (PCR) techniques.

Main Results:

• Thirteen different alleles of the leptin gene polymorphism were identified in obese cases, compared to only five in controls.
• Obese individuals exhibited a significantly higher carriage rate of class II alleles (OR=14.6) compared to healthy controls (p<0.0001).
• This association was more pronounced in simple obesity (OR=17.2) than in metabolic syndrome cases (OR=12.19), though no significant difference was found between these two obese groups regarding allele frequencies.

Conclusions:

• The tetranucleotide repeat (TTTC)n polymorphism in the 3' UTR of the human leptin gene is associated with obesity in the Egyptian population.
• A higher carriage rate of class II alleles of this polymorphism is a risk factor for obesity, particularly simple obesity.
• Serum lipoprotein levels were not found to be affected by this specific leptin gene polymorphism in the studied population.