Causes of abnormal growth in body according to scientist

 Growth problems” is a broad phrase used to describe various causes and effects of conditions relating to your child’s insufficient growth.

• About 3 to 5 percent of children are considered to be short, meaning that their heights are below the 3rd or 5th percentiles on a growth chart. Many of these children have one or more short parent, and only a few will have a specific and treatable medical growth problem.
• A growth problem may be clear at birth, if your child is abnormally small for his age. Or, it may surface if he remains underdeveloped compared to his peers.
• A child is considered to show “growth delay” when he is small for his age, but grows for a longer period of time compared to other children, often reaching a normal height.

Here at Boston Children's Hospital, growth problems are treated through our Division of Endocrinology — through a multidisciplinary program that provides comprehensive diagnosis, treatment, and management for patients with growth disorders and other disorders associated with the endocrine system.

We evaluate children with poor growth, improve their overall nutrition, and promote healthful eating habits.

How is “normal” growth defined?

Measured in height, “normal” growth is described as growth of:

• 0 to 12 months: about 10 inches. Growth during this phase is primarily a function of nutrition.
• 1 to 2 years: about 5 inches. From the age of 1, hormonal factors play an increasingly important role in your child’s growth.
• 2 to 3 years: about 31/2 inches a year
• 3 years to puberty: about 2 inches a year. There is minimal difference in growth seen in boys and girls until puberty, which results in an average height difference of 4 to 5 inches between the sexes.

What are the symptoms of a growth problem?

The primary symptom that may indicate a growth problem is when a child grows less than 2 inches a year after his second birthday. Other symptoms may include:

• slow development of physical skills, such as rolling over, sitting up, standing, and walking
• delayed social and mental skills
• delayed development of secondary sexual characteristics in adolescence

What causes growth problems?

Growth problems can be caused by a number of factors, including genetics, hormonal disorders, systemic illnesses, and poor absorption of food. Causes of growth problems usually fall into the following categories:

• familial short stature, a tendency to follow the family's inherited short stature (shortness)
• constitutional growth delay, also known as delayed puberty. A child with this condition enters puberty later than average, but is growing at a normal rate. Most of these children tend to eventually grow to about the same height as their parents.
• illnesses that affect the whole body, also called systemic or chronic illnesses, or illnesses that affect the digestive tract, kidneys, heart, or lungs
• malnutrition. Constant malnutrition prevents a child from growing as tall as she could; a well-balanced diet generally prevents or corrects this. Malnutrition is the most common cause of growth failure around the world.
• severe stress
• endocrine (hormone) diseases, such as diabetes or a lack of thyroid hormones, which are necessary for normal bone growth
• syndromes (genetic disorders). Growth problems may be a feature of syndromes such as Cushing's syndrome, 
•  Turner syndrome, Down syndrome, Noonan syndrome, Russell-Silver syndrome, and Prader-Willi syndrome.
• growth hormone deficiency. A child with this growth disorder has a problem with the pituitary gland (small gland at the base of the brain) that secretes several hormones, including growth hormone.
• congenital (present at birth) problems in the tissues where growth occurs
• intrauterine growth restriction (IUGR). This condition results from a fetus’s slow growth within the uterus. The baby is born smaller in weight and length than normal, in proportion to his short stature.
• chromosome abnormalities. Having too many or too few chromosomes can result in health problems, including problems with growth.
• skeletal abnormalities. There are more than 50 bone diseases that affect height and growth, many of which are genetic. The most common is achondroplasia, a type of dwarfism in which the child's arms and legs are short in proportion to his/her body length. The head is often large and the trunk is normal-sized.
• precocious puberty. This growth disorder is characterized by an early onset of adolescence in which a child is tall for his age initially, but due to rapid bone maturity, growth stops at an early age and the child may be short as an adult.
• genetic conditions. There are a few genetic conditions that result in tall stature, where other health problems are also present.
• Idiopathic. There are several growth disorders that are idiopathic, meaning that there is no known cause for the growth problem.
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