The incidence of idiopathic growth hormone deficiency (GHD) in infants is about 1 in every 3800 live births. It is estimated that GHD affects one  in every 4,000 school-age children. GHD occurs three or four times more often among boys than girls. 65 per cent  of children who have received radiation therapy for diseases such as leukemia or middle ear or nasopharyngeal tumours have deficiencies in growth hormone. Children with physical defects of the face and skull, such as cleft lip or palate are more likely to have decreased growth hormone level. Global data estimates that the global GHD therapeutics market values $1,354.5 million in 2010.

Growth of human body is a dynamic process and optimal gain in height and weight is an essential marker of good health. The growth in a broad perspective includes gain in weight and height besides attainment of puberty and maturation of various organ functions. Often growth is equated with gain in height as it is a constantly increasing parameter and which unlike weight, does not decrease once attained. Thus height gained by a child is used as a direct measure of growth achieved.

There are various factors which affect human body growth. The growth is affected by good nutrition, balanced diet with adequate intake of calories and proteins besides mineral and vitamins are essential for good growth. Absence of any diseases and chronic illnesses promotes growth. Children with diseases related to heart, kidneys, anemia, asthma, malabsorption or digestive disturbances etc. may not grow adequately if these diseases are not adequately treated. It is important to note that all children grow as per their genetic potential. Thus children of tall parents are expected to be as tall and children of short parents are genetically small. Genetic factors can be overcome to some extent with good exercise, activity and balanced diet.

The rate of growth varies with the age of the child. In the first year of life a baby puts on 20-24 cm in length as compared to second year wherein the gain is about 12 cm. Subsequently the rate of increase in height gradually decreases to 4-6 cm per year until the child enters puberty wherein again there is a growth spurt. It is always good to measure the height of each child every year and plot it on the growth chart.

GHD is a disorder that involves the pituitary gland (a small gland located at the base of the brain) that produces growth hormone and other hormones. When pituitary gland does not produce enough growth hormone, growth becomes slower than normal.  This hormone enters the blood and stimulates liver to produce a hormone called insulin-like growth factor (IGF-1), that plays a key role in childhood growth. GHD could be congenital (a condition that is present at birth) in nature or an acquired (a condition that occurs after birth) condition. Acquired causes include trauma, infections, radiation to the head, and other diseases (e.g., brain tumours).

In children, the growth hormone is responsible not only for gaining in height but also for muscle strength, bone development, the distribution of body fat and having good metabolism of fat, carbohydrate and proteins. They may also have an increased amount of fat around the waist & face. In older children, puberty may come late.

Detection and diagnosis
Early diagnosis of GHD is the first step towards its treatment. While evaluating a child’s growth, a growth chart is used to analyze the growth rate / growth velocity, in comparison with other children of the same age and gender. Accurate annual measurements and plotting of a child's height on growth chart allows timely identification of growth failure and treatment. It is imperative for parents to identify the GHD in their child at a nascent stage to avoid delay in evaluation and treatment which in turn will prevent probable loss of permanent inches. A child’s height is also compared with the parent’s height as often genetic factors also determine an individuals’ growth potential.

Remedial steps to be taken once the deficiency has been detected
An endocrinologist (a doctor who specializes in studying hormones) may perform the following tests to rule out other causes of growth delay:
 

• Thyroxin and thyroid-stimulating hormone to test for hypothyroidism (decreased production of thyroid hormone)

• Serum electrolytes to test for certain kidney conditions

• A complete blood count

• Insulin like growth factor 1 (IGF-1) and insulin like growth factor binding protein 3 (IGFBP-3) (proteins that depend on growth hormone)

• A Karyotype (a study of a person’s chromosomes) may be performed in girls to rule out Turner syndrome.

• Hand X-ray (usually the left hand) to determine the child’s bone age.

• MRI of the head to exhibit the hypothalamus and pituitary glands.

Children with a flat rate of growth as compared to their classmates experience physical, social and emotional problems, including a lowered self-esteem. Psychological counseling can help children with feelings of low self-esteem or sadness that may be related to growth hormone deficiency. Remember, GHD is a sign of disease but, in itself, it’s not a disease in which a child’s growth pattern is an important determiner of his/her normal growth.  Family, friends, and teachers should strongly emphasize the child's special skills and strengths and help them boost their morale regularly.

It is important to help a child gain height to his/her potential in a timely manner as “Children have a short time to grow and a life time to live those results”.