Type 2 Diabetes Mellitus

Diabetes Mellitus is a metabolic disease that causes excess blood sugar. There are three types of diabetes: Juvenile onset diabetes, Type 2 Diabetes and Gestational Diabetes.

Type 2 diabetes is a disease that usually occurs in middle to old age adults, generally overweight or obese. There are several factors that cause the onset of type 2 diabetes. The most common are: insulin resistance and family history. 

Insulin resistance is when the body doesn’t use the insulin produced effectively, insulin uses sugar for energy.It usually occurs in people with excess abdominal fat, the body’s liver, muscle etc, doesn’t use the insulin effectively.When a person’s body is resistant to insulin, sugars aren’t used for energy, so sugar is left in the blood stream resulting in excess blood sugar. This forces the pancreas to produce more insulin, if the pancreas can produce enough insulin, blood sugar levels stay normal. However, diabetes occurs when the pancreas can’t produce enough insulin to compensate for the body’s lack of ability to use insulin.

Another factor that can make a person more or less susceptible to diabetes is family history. The presence of certain genes or lack thereof can affect whether the person will suffer for diabetes. Studies have shown that people inheriting variants of gene TCF7L2 have a higher chance of having diabetes. People who have two copies of the gene variants have 80% more chance of having type 2 diabetes than people without the gene.


Causes of Diabetes. 2011. [online] Diabetes.niddk.nih.gov. Available at: <http://diabetes.niddk.nih.gov/dm/pubs/causes/#causes&gt; [Accessed 18 Mar. 2014].

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Horikawa, Y., Oda, N., Cox, N., Li, X., Orho-Mel, er, M., Hara, M., Hinokio, Y., Lindner, T., Mashima, H., Schwarz, P. and others, 2000. Genetic variation in the gene encoding calpain-10 is associated with type 2 diabetes mellitus. Nature genetics, 26(2), pp.163–175.

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What is Diabetes? What Causes Diabetes?. 2003. [online] Medicalnewstoday.com. Available at: <http://www.medicalnewstoday.com/info/diabetes/&gt; [Accessed 18 Mar. 2014].

Further Reading



Gene Therapy

Gene therapy is a promising yet complicated way of replacing defected or mutated genes. Although, this form of treatment hasn’t been made available for the general public it has moved from the research stage to clinical trials for a variety of diseases. In most cases, gene therapy is used in an attempt to cure cancer diseases (64.4% of all clinical trials: data collected in 2007). Several types of cancer diseases have been targeted including lung, skin, urological (urinary tract system) and neurological (nervous system).

Cystic fibrosis is a monogenic (resulting from changes in one gene in all of the body) disease that affects the respiratory, digestive and reproductive systems. A build up of mucus in the lungs can lead to harmful lung infections. It is the most common inherited disease in Europe and the USA. The life expectancy of someone suffering from cystic fibrosis is under 40 years. This is the reason for Cystic Fibrosis to be the main focus for gene therapy.

How Gene Therapy works (simple explanation)?

  1. The defective gene causing the problem or disease is identified.
  2. The site of the affected tissue or muscle is targeted and pinpointed, sometimes the defective gene is ‘silenced’ or cut out using an enzyme.
  3. A working gene must be obtained.
  4. The working gene is put into the gene via the use a vector in a virus.

The future for gene therapy is bright, several research journals have shown positive results.

Full list of diseases attempted to be cured by gene therapy in clinical trials (research journal: Gene therapy clinical trials worldwide to 2012 – an update, look in bibliography for full reference):


Siddharth Jain (King George V School, HK) – 17/04/2014


Genetics Home Reference – Your guide to understanding genetic conditions. 2014. [online] Ghr.nlm.nih.gov. Available at: <http://ghr.nlm.nih.gov/&gt; [Accessed 17 Apr. 2014].

Ginn, S., Alex, er, I., Edelstein, M., Abedi, M. and Wixon, J., 2013. Gene therapy clinical trials worldwide to 2012–an update. The journal of gene medicine, 15(2), pp.65–77.

Learn.Genetics.utah.edu. 2014. [online] Learn.genetics.utah.edu. Available at: <http://learn.genetics.utah.edu/&gt; [Accessed 17 Apr. 2014].

WHO | Genes and human disease. 2014. [online] Who.int. Available at: <http://www.who.int/genomics/public/geneticdiseases/en/index2.html#CF&gt; [Accessed 17 Apr. 2014].