LCT Gene

The LCT gene region includes the adjacent LCT and MCM6 genes. The LCT gene encodes lactase, an enzyme produced in the small intestine to help digest lactose, a sugar in dairy. The MCM6 gene acts as a regulator, influencing when LCT produces lactase.

Alleles

People normally have two alleles per gene, one inherited from their mother and one inherited from their father.

Off (Global)

This allele has been widespread globally for tens of thousands of years.

Other (European)

This allele originates from an ancient European mutation that occurred thousands of years ago.

On (European)

This allele originates from an ancient European mutation that occurred thousands of years ago.

Allele Pairs

It is the combination of a person's pair of gene alleles that influences traits.

Predictable Lactose Intolerance
Allele Pair People with this allele pair usually tolerate less lactose in adulthood than adults with one or two “On” alleles. The influence of this allele pair is present during adulthood and not early childhood.
No Prediction Lactose Digestion
Allele Pair It has not yet been determined what influence these allele pairs have on lactose digestion, due to lack of data on the "Other" allele type.
Predictable Lactose Tolerance
Allele Pair People with these allele pairs usually digest more lactose in adulthood than adults with two "Off" alleles.

Gene Details

The LCT gene is located on chromosome 2 and encodes the protein named "Lactase", which influences the reported traits.

The adjacent MCM6 gene regulates how much protein is produced by LCT.

Additional References LCT MCM6
Genetics Home Reference by the U.S. National Library of Medicine LCT
Wikipedia Lactase MCM6
SNPedia LCT MCM6
UniProt P09848
U.S. National Center for Biotechnology Information 3938 4175

PubMed articles

Allele Definitions

[0] [1]
Off
G
C
C
G
On
A
T
T
A
Other
G
C
T
A
Show Minus Strand
+
-
+
-
Single Nucleotide Polymorphisms (SNPs)
[0] rs4988235 dbSNP SNPedia
[1] rs182549 dbSNP SNPedia