MCM6/LCT: Lactose Tolerance

rs4988235 · Nutrient Metabolism

This variant determines whether you continue producing lactase into adulthood — the difference between lactose tolerance and lactose intolerance.

What This SNP Does

The lactase persistence trait is regulated by a variant in the MCM6 gene, upstream of LCT (lactase). The T allele maintains LCT expression into adulthood (lactase persistence), while CC leads to declining lactase production after weaning (the ancestral, globally more common state). ~65-70% of the world's population is lactose non-persistent.

Genotype Meanings

Genotype	Status	What It Means
TT	Persistent	Lactase production continues into adulthood. Can digest dairy without issues.
CT	Partial	Intermediate lactase production. May tolerate moderate dairy but have symptoms with large amounts.
CC	Non-persistent	Lactase production declines after childhood. Likely lactose intolerant. Fermented dairy (yogurt, aged cheese) often tolerated.

What You Can Do

CC individuals should consider lactase enzyme supplements with dairy, or choose fermented dairy products (yogurt, kefir, aged cheeses) which are pre-digested. Ensure adequate calcium from non-dairy sources if avoiding dairy entirely.

This information is for educational purposes only and is not medical advice. Always consult a qualified healthcare provider before making health decisions based on genetic data. Genome Decoder does not diagnose, treat, or prevent any disease.