Lactase (LCT Gene) Mutation Testing

Lactase (LCT gene) mutation testing serves as a diagnostic tool aimed to identify the underlying reason for lactose intolerance, a condition characterized by the inability to effectively digest lactose found in dairy products like milk. This intolerance is linked to genetic abnormalities, particularly mutations in the LCT gene. The presence of these abnormal genes is a contributing factor to the development of lactose intolerance in both children and adults.

Causes of lactose intolerance
Causes of lactose intolerance can be categorized into three types:

1. Congenital Lactase Deficiency:
    – This form affects infants, rendering them unable to digest lactose present in breast milk or formula.
– The underlying cause stems from a genetic abnormality inherited from both parents.

2. Lactase Deficiency (Primary Lactase Deficiency/Primary Adult Type Hypolactasia):
– Typically observed in adults or older children, primary lactase deficiency results from a mutation in the LCT gene.
– This gene is essential for synthesizing the enzyme lactase in the small intestine, and a mutation leads to an abnormal enzyme structure (Lactase non-persistence).
– The extent of enzyme reduction varies with age, genetics, and race.

3. Enzyme Deficiency following Secondary Lactose Intolerance:
– Occurs due to damage to the small intestinal wall, causing a temporary decrease in lactase enzyme production.
– Triggers include factors such as viral infections, infection with intestinal protozoan parasites, celiac disease (inflammation linked to gluten consumption), and chronic inflammatory bowel disease like Crohn’s disease.