Growth hormone receptors are the ones responsible for proper growth and development of the body. One may ask what can be the outcome if a person is deficient with these growth hormones. The following facts will explain more about growth hormone receptor deficiency.
About Growth Hormone Receptors
This hormone is secreted by the anterior pituitary gland and is responsible for the growth and metabolism of the human body. It is consisted of a polypeptide chain of 191 amino acids known as the “Growth Hormone.” It binds specific receptors within the body which trigger various cellular responses as soon as this hormone binds them together.
If a person is deficient with this growth hormone, it will result to growth-related disorders. Even a person who has enough levels of growth hormone in the body may show retarded growth if he lacks growth hormone receptors. The improper functioning of these receptors can cause Laron syndrome which is characterized by dwarfism, delayed bone growth and insensitivity towards administered growth hormone.
Mechanism of Activation
Activation occurs when the growth hormone binds with the growth hormone receptor. Because of the binding, the catalytic domains of tyrosine-protein kinase JAK2 position themselves on both sides below the membranes of the cell. This will then cause the activation of JAK2 as a result of transphosphorylation followed by phosphorylation of tyrosins of the receptor. It allows the target proteins to bind with direct phosphorylation of target proteins.
Types of Growth Hormone Receptor Deficiency
Type 1 growth hormone receptor deficiency refers to the defect in growth hormone receptor gene which prevents the binding of growth hormone to its particular receptor. As a result, there is an increased level of hormone in the plasma since this is not utilized in the body. On the other hand, Type 2 is one where the growth hormone binds properly to the cell surface but there are problems regarding its processing.
Causes and Symptoms of Deficiency
This kind of deficiency is rare and it is hereditary from the parents in an autosomal recessive manner. Symptoms of deficiency would include: increased level of growth hormone within the body; severe retarded growth after birth; short stature; both hands and feet are short; abnormal growth of skull; not fully developed jaw and muscles; delayed puberty; thin skin; obesity; high cholesterol in the blood; and low fasting blood glucose level.
This deficiency can be treated through the recombinant human Insulin-like growth factor (IGF-1). Aside from this, a child suffering from this deficiency can be given frequent meals during infancy to prevent hypoglycemia. Doctors must have to check the growth and development, blood glucose levels and development of adverse effects caused by IGF-1. Once IGF-1 is administered together with the naturally occurring growth hormone in the body, one can surely increase the amount of circulating growth hormone within the body. This will then result to over activation of the receptors causing gigantism and acromegaly. In case the receptors are activated due to autocrine activation, this can result to cancer and cell transformation.
As soon as you may notice a growth hormone receptor deficiency symptom in a person, you may consult your doctor at once. This is so that he can immediately start the treatment in order to prevent growth and development disorders as well as regulate the metabolic activity of that person.