Maturity Onset Diabetes of the Young (MODY)

This is a rare type of diabetes. Patients are non-insulin dependent. Most of them can be treated by oral hypoglycemic drugs.

Some of its Important features:

* Primary defect is impaired glucose induced secretion of insulin.

* Age is usually less than 25 years.

* This is inherited by a mechanism called autosomal dominance.

* No autoimmunity (as in type 1)

* No insulin resistance (as in type 2)

* No obesity (as in type 2)

MODY is absolutely different category. It doesn’t lead to type 2 diabetes in old age.

What are the causes of MODY?

There are six types of MODY. Except MODY 2, all are caused by mutations of nuclear transcription factor that regulates islet cell gene expression.

MODY 2 is caused by mutation of Glucokinase enzyme. Glucokinase enzyme in beta cells controls the glucose entry in to beta cells which inturn coupled with insulin release. Mutations of this enzyme increase threshold for insulin release. So insulin secretion is low for the degree of hyperglycemia.

Clinical course:

Usually mild type of diabetes occurs with slight fasting hyperglycemia and few mild symptoms of micro vascular complications. Upto 50% of carriers of glucokinase mutations develop gestational diabetes.

[tags]mody, diabetes, diabetic[/tags]

All Types Of Diabetes!!

Though most people know only type 1 and type 2 diabetes, there are other minor variants of diabetes.

Type 1 diabetes :

* It’s genetic inheritance – Risk increases 20 – 50% if an identical twin is affected. More common with certain class II HLAs.

 * Complete dependency on insulin treatment – Most of the patients need insulin in their daily life. The dose should be adjusted according to their demands, exercise and other stress factors.

* Young age onset – Around puberty.

* Autoimmune destruction of beta cells in pancreas (Body defense cells called lymphocytes destroy own body cells) – Lymphocytes of the patient are sensitized to his/her own beta cells destroying them.

* Development of ketoacidosis – Most serious complication of type 1 diabetes. As most patients depend on exogenous insulin for their blood sugar control, there should be fine balance between the demand and the supply. If there is more demand for insulin (like surgeries,exercise, pregnancy) and less supply (like missing insulin injections), they easily prone to high glucose levels and ketosis.

Type 2 diabetes :

* It’s genetic inheritance – 50 – 90% of risk if an identical twin is involved.

* Insulin resistance – Main pathology behind this type of diabetes. There are many genetic defects in insulin receptors that causes insulin resistance.

* Partial insulin deficiency – Still some insulin secretion will be preserved, atleast in most of the patients. Beta cell mass is reduced to 50% of normal at the time of diagnosis.

* Age over 40 years

* No autoimmunity – No role for autoimmunity as in type 1 diabetes.

* Development of Hyperosmolar nonketotic coma instead of ketoacidosis – This complication is common in type 2 than type 1. Due to hyperglycemia and impaired water intake in elderly diabetics.

* Insulin treatment sometimes – Usually oral antidiabetic drugs are given to control blood glucose. Some of these drugs enhances the insulin secretion from beta cells. Insulin is last resort if diet, exercise, oral drugs fail.

* Often obese – Central obesity appears to trigger the disease in persons who are genetically susceptible.

Maturity onset diabetes of the Young (MODY) :

* Primary defect is impaired glucose induced secretion of insulin.

* Age is usually less than 25 years.

* This is inherited by a mechanism called autosomal dominance.

* No autoimmunity (as in type 1)

* No insulin resistance (as in type 2)

* No obesity (as in type 2)

MODY is different category. It won’t lead to type 2 diabetes in old age.

Gestational diabetes :

Placenta in preganancy produces anti-insulin hormones that counteract the actions of insulin. So pregnant woman can not maintain normal glucose levels in blood exhibiting glucose tolerance. Fortunately, the condition disappears once the baby was delivered.

Risk factors are obesity, happens when more than 30 years of age, positive family history, unexplained still birth, polyhydromnios (excess amniotic fluid)

Other types of diabetes (secondary causes):

* Diabetes associated with insulin gene or insulin receptor genes.

* Pancreatic diseases like chronic pancreatitis, cystic fibrosis,hemochromatosis.

* Endocrine disorders like acromegaly, cushing’s syndrome, hyperthyroidsm.

* Exogenous administration of glucocorticoids.

[tags]gestational diabetes, mody, type 1 diabetes, type 2 diabetes, diabetes, diabetic[/tags]