Laron Syndrome

What is Laron Syndrome?

Laron syndrome is also known as Laron-type Dwarfism, GH receptor Deficiency, Pituitary dwarfism II, Growth Hormone insensitivity, or Growth Hormone unresponsiveness, among many other terminologies. It is a disorder brought about by the inability of the body to utilize growth hormone, leading to affected individuals having short stature. This growth hormone is secreted by the pituitary glands located in the brain.

Although it does not affect an individual’s lifespan, it leads to certain abnormalities and undesirable features. Laron syndrome is an autosomal recessive disorder that is inherited by offspring of carrier parents.

Causes

Laron syndrome is caused by a genetic mutation of the growth hormone receptor gene. It is an autosomal recessive disorder. This means it occurs when two people each carrying a copy of the mutated gene have sex and give birth to kids. The parents normally do not have the signs of this disorder known as Laron syndrome.

1 in 4 kids is likely to get this particular disorder if their parents were carriers. This particular gene is responsible for encoding the Growth Hormone Receptor (GHR).

Growth Hormone Receptor is a protein and is located on the outermost membrane of cells throughout the body. Its main purpose is to recognize and bind growth hormone. This, in turn, leads to cellular division, which results in growth in terms of both girth and height.

Growth hormone bound by Growth Hormone Receptor on liver cells leads to the production of Insulin-like Growth Factor I (IGF-1), which is a hormone very important in promoting growth.

Mutation of the gene inhibits work of the growth hormone receptor. This means the growth hormone and growth hormone receptor do not bind leading to lack of cell division and thus lack of growth. The disorder can also occur as a result of new gene mutation even in cases where none of the parents are carriers of the mutated gene.

Laron syndrome can also be caused by marriages among relatives.

Signs & Symptoms

Laron syndrome manifests itself in various signs and symptoms. Although not painful, they can very fast be the cause of serious self-esteem issues among individuals affected by Laron syndrome disorder. These signs and symptoms include;

• Patients have protruding or high lifted foreheads
• Patients have small genitals in most cases
• When compared, the limbs of most patients happen to be shorter than their torso
• Obesity is experienced, especially in elder patients affected by Laron syndrome
• Low sugar levels is noticed in infants with Laron syndrome disorder
• Most patients with Laron syndrome have dental abnormalities. These range from reduced number of teeth to delay in eruption or growing of teeth.
• The puberty stage of most patients affected by Laron syndrome is often delayed
• Patients experience reduced muscle strength
• Patients have low endurance capabilities
• The whites of the eyes of most people with Laron syndrome tend to be blue in color
• Most patients have small hands and small feet
• A saddle nose can be observed in most people affected by the disorder
• Delayed skeletal maturation is another sign of Laron syndrome
• Most patients have thin and fragile hair
• The most obvious sign or symptom in Laron syndrome is the short stature. If not treated, most females grow to be 4 feet while males grow to be only 4.5 feet tall.

Diagnosis

Laron syndrome is diagnosed through various methods as discussed below:

Physical examination

Laron syndrome can easily be diagnosed by carefully observing the symptoms manifesting in the affected individual.

Blood test

This is done to measure the levels of certain hormones in the blood. Individuals with Laron syndrome disorder tend to have abnormal hormone levels – for example, extremely high levels of growth hormone and low levels of Insulin-like Growth Factor ¹.

Genetic test

It is done to test mutation of the individual’s genes. The genetic test is a sure means of confirming diagnosis for Laron syndrome and ruling out other disorders with similar symptoms like those of Laron syndrome.

Treatment

A permanent cure for Laron syndrome disorder is yet to be discovered by scientists and researchers. All treatment methods in application just help in promoting growth. Treatment is most effective if done before puberty because during this time, bones are still open.

IGF 1 injections

These are subcutaneous injections of Insulin-like Growth Factor 1 (IGF-1). These injections have tons of benefits to the sick individual. They help increase growth of muscles. They promote linear growth, which means the individual affected by Laron syndrome can grow taller.

The injections stimulate growth of the brain. They rectify abnormalities present that were caused by a deficiency in Insulin-like Growth Factor. The injections also reduce blood cholesterol and increase sugar levels present in the blood.

Although extremely helpful, an overdose can however be detrimental to the health of the Laron Syndrome patient.

Mecasermin

This is a medication employed in long term treatment of Laron syndrome. It is used in kids with severe deficiency of Insulin-like Growth Factor ^1.

Mecaserminrinfabate

It is a medicine used mostly in kids with severe Insulin-like Growth Factor 1 deficiency. It is also used in individuals with Growth Hormone deletion. Such individuals tend to develop antibodies to growth hormone.

Diet

Individuals with Laron syndrome disorder are advised to take foods with high caloric intake. Not too much such that it results in obesity. Just enough.

Laron syndrome like earlier stated does not affect the lifespan of an individual. Despite having upsetting ways of manifestation like protruding foreheads, abnormal dental formulae and small genitals, it has its advantages. Call it the ‘silver lining’ in this particularly dark cloud.

Individuals with Laron syndrome disorder have very low possibilities of having cancer or diabetes mellitus type two.

Reference List

1. Laron syndrome. Available at https://ghr.nlm.nrh.gov/condition/laron/syndrome
2. Causes of Laron Syndrome. Available at https://rarediseases.info.nih.gov/diseases/6859/laron-syndrome
3. Laron syndrome. Available at www.emedicinespace.com/article/9222902-overview
4. Effects of Laron syndrome. Available at https://www.fightingaging.org/archives/2016/02/a-look-at-the-laron-syndrome-population/
5. Treatment of Laron Syndrome autosomal recessive disorder. Available at www.webmd.com/children/laron-syndrome
6. Diagnosis, management and treatment of Laron syndrome disorder. Available at www.orpha.net/consor/cgi-bin/OC-Exp.php?Lng=EN&Expert=633
7. Definition, causes, symptoms and treatment of Laron Syndrome disorder. Available at https://www.medigoo.com/articles/laron-syndrome/