Myths vs facts: MC4R and fertility

The claim that MC4R variants directly affect fertility is largely a myth. MC4R (melanocortin-4 receptor) is primarily involved in appetite regulation and energy balance. Some SNPs (e.g., rs17782313) are weakly associated with higher BMI, and obesity can impair fertility indirectly. However, direct evidence linking MC4R to reproductive function independent of BMI is limited to mechanistic or small observational studies. Direct-to-consumer DNA tests often market MC4R as a 'fertility gene,' which overstates its clinical utility. Fertility is multifactorial—hormonal status, age, lifestyle, and underlying conditions play far larger roles. A single SNP explains <1% of BMI variance, and its impact on fertility is negligible for most people. If you have fertility concerns, consult a reproductive specialist rather than relying on a consumer genetic test. Evidence: marketing/unclear.