Human Phenotype Ontology 
Grandparent Node:
expandAbnormality of the small intestine (HP:0002244)help
Parent Node:
expandAbnormal enzyme/coenzyme activity (HP:0012379)help
Parent Node:
expandAbnormal small intestinal mucosa morphology (HP:0025129)help
..Starting node
..expandDecreased small intestinal mucosa lactase level (HP:0025130)help
Term ID: 25130
Name: Decreased small intestinal mucosa lactase level
Synonym: Lactase deficiency
Definition: Lactase is produced in the small intestine in humans, Lactase is a member of the beta-galactosidase family of enzymes, and hydrolyzes D-lactose to form D-galactose and D-glucose, which can be absorbed by the small intestine. There are many ways of assessing lactase activity. In one test, an endoscopic biopsy from the postbulbar duodenum is incubated with lactose on a test plate, and a color reaction develops within 20 min as a result of hydrolyzed lactose (a positive result) in patients with normolactasia, whereas no reaction (a negative result) develops in patients with severe hypolactasia. Other, less direct, tests include the hydrogen breath test, and blood tests following lactose challenges.
Comments:
Reference: HP:0025130
Genes and Diseases:
 
       Child Nodes:

 Sister Nodes: 
InputHPO IDHPO termDistanceGeneGene id entrezHGNC IDDiseaseIdDiseaseNameFrequencyOnsetHGMD variantsClinVar variants
 
HPO disease - gene - phenotype typical associations:
 
HPO disease - gene - phenotype less frequent non-typical associations:
HP:0025130HP:0025130Decreased small intestinal mucosa lactase level0LCT CL E G H39386530OMIM:223000Lactase deficiency, congenital.HP:0003577 - Congenital onset72
HP:0025130HP:0025130Decreased small intestinal mucosa lactase level0MCM6 CL E G H41756949OMIM:223100LACTOSE INTOLERANCE, ADULT TYPE5


Genes (2) :LCT MCM6

Diseases (2) :OMIM:223000 OMIM:223100
 

Human Phenotype Ontology(HPO) is developed by the Human Phenotype Ontology Consortium. The version used here is December 15 2022 release.