Lactose Intolerance

By: Ryan Mayville


Lactose intolerance is caused by a deficiency in the LCT gene. LCT provides the instructions for making the enzyme that breaks down lactose in your body. Infants are diagnosed with lactose intolerance from a mutation in the LCT gene. Adults are diagnosed with Lactose Intolerance from decreased activity of the LCT gene after infancy.

Symptoms and biology of disease

Symptoms of Lactose Intolerance include gas, belly aches, diarrhea, throwing up, pain cramps etc. Lactose Intolerance is caused when the small intestines don't produce enough of an enzyme called lactase. The amount of the enzyme produced isn't enough to absorb much lactose if any.

Type of mutation and inheritance

At a specific point of a DNA sequence cytosine is replaced with thymine or a single nucleotide polymorphism. If thymine is present than adults will continue to produce lactase without an ill affect but if it this mutation hasn't occurred or hasn't occurred properly than the body will struggle to produce lactase. Lactose intolerance is an autosomal recessive pattern in the DNA.

Treatments and Diagnosis

To be diagnosed with lactose Intolerance you must take many tests. A stool acidity test can give you an accurate reading of whether or not you are lactose intolerant. you can also take a test where you drink a drink of high lactose and after two hours your blood is drawn and if your glucose level hasn't changed than you are lactose intolerant. If you have lactose intolerance than you have it for life but you can manage. The easiest way to manage is to cut dairy out of you diet and try alternatives.