LCT
Lactase (phlorizin hydrolase)
Gene Number: 3938
Location: 2q21.3
Key Functions: Lactose digestion, lactase enzyme production, nutrient absorption, gastrointestinal health
LCT encodes lactase, an enzyme produced in the small intestine that breaks down lactose—the primary sugar in milk—into glucose and galactose for absorption. Proper lactase activity is essential for digesting dairy products and supporting nutrient uptake, especially during infancy and early childhood.
Variations in LCT influence whether lactase production persists into adulthood. Reduced LCT activity results in lactose intolerance, leading to gastrointestinal symptoms such as bloating, gas, and diarrhea after dairy consumption.
SNP ID | Your Genotype | Alternative Alleles | Interpretation |
|---|---|---|---|
rs4988235 | No matching variant or no valid DNA data | A | No interpretation available |
rs182549 | No matching variant or no valid DNA data | T | No interpretation available |
rs4988235
AA – Lactase persistence; can digest milk as an adult (R).
AG – Mostly lactase persistent; ~80% can digest milk as adults (R).
GG – Lactase non-persistence; likely lactose intolerance in adulthood (R).
Functional effect: The A allele (-13910*T, in an enhancer within MCM6) upregulates LCT expression, maintaining lactase into adulthood; strongest evidence in Europeans (gene–environment/ancestry effects apply) (R).
rs182549
TT – Lactase persistence; commonly able to digest milk as an adult (R).
CT –Often lactase persistent; effect tracks with LD to rs4988235-A in many Europeans (R).
CC – Lactase non-persistence risk; especially when combined with rs4988235-GG (R).
Functional effect: The T allele (-22018A, enhancer in MCM6) is in strong LD with -13910T; together they increase LCT transcription and predict lactase persistence in a large share of Europeans (R).
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