Defective LCT does not hydrolyze Lac

Stable Identifier
R-HSA-5658001
Type
Reaction [transition]
Species
Homo sapiens
Compartment
extracellular region, plasma membrane
ReviewStatus
5/5
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Defective LCT does not hydrolyze Lac
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Mutations that disrupt the catalytic activity of LCT (lactase) block the cleavage of lactose (Lac) to galactose and glucose in the gut lumen and cause lactose intolerance in nursing infants. Affected individuals can develop severe diarrhea; the disease can be effectively managed by complete exclusion of lactose from the diet. A variety of LCT mutant alleles have been described. Two missense mutations that are associated with severe loss of lactase activity in vivo are annotated here (Kuokkanen et al. 2006; Torniainen et al. 2009).
Literature References
PubMed ID Title Journal Year
19161632 Four novel mutations in the lactase gene (LCT) underlying congenital lactase deficiency (CLD)

Catassi, C, Savilahti, E, Routi, T, Torniainen, S, Freddara, R, Gijsbers, C, Järvelä, I, Höglund, P

BMC Gastroenterol 2009
16400612 Mutations in the translated region of the lactase gene (LCT) underlie congenital lactase deficiency

Peltonen, Leena, Komu, H, Varilo, T, Savilahti, E, Enattah, NS, Kokkonen, J, Kuokkanen, M, Järvelä, I, Ylisaukko-Oja, T

Am. J. Hum. Genet. 2006
Participants
Input
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as an event of
Catalyst Activity

lactase activity of LCT mutant dimers [plasma membrane]

Physical Entity
LCT mutant dimers [plasma membrane] (Homo sapiens)
Activity
lactase activity (GO:0000016)
Normal reaction
lactose + H2O => D-glucose + D-galactose (Homo sapiens)
Functional status

Loss of function of LCT mutant dimers [plasma membrane]

Normal Entity
Disease Entity
Status
Disease
Name Identifier Synonyms
lactose intolerance DOID:10604 LM - Lactose malabsorption
Authored
D'Eustachio, P  (2015-02-15)
Reviewed
Amiri, M  (2015-02-15)
Naim, HY  (2015-02-15)
Jassal, B  (2015-01-29)
Created
D'Eustachio, P  (2014-12-16)
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