Growth disorders
Growth is one of the complex and amasing facts of life that most people take for granted, but it can be a cause for concern for parents who have a child who’s shorter than others of the same age and doesn’t appear to be growing any taller.
Causes of delayed growth
There are a large number of medical, genetic and external factors that can delay or inhibit normal growth. These include conditions such as Growth Hormone Deficiency (GHD) in children, Turner’s syndrome, Down’s syndrome, achondroplasia (defective growth of cartilage cells in the bones of the limbs) and various malfunctions of the endocrine system.
Chronic diseases and illnesses can also have a detrimental effect on growth including Inflammatory Bowel Disease IBD, chronic renal insufficiency and heart disease, as too can factors such as malnutrition, drug and alcohol abuse, neglect, chronic stress and lack of exercise. However, in many cases the cause of delayed or restricted growth is not known.
Many children are smaller than average during childhood yet end up reaching a normal adult height. But for some, a more normal adult height will not be achieved without treatment with supplemental human growth hormone (hGH). These include children with GHD and Turner’s syndrome.
One out of 2,500 to 5,000 children is born with a deficient growth hormone production resulting in impaired physical development, and another one in 2,000 to 2,500 girls are born with the genetic defect Turner’s syndrome. Both disorders may result in decreased final height, which may be improved by supplemental somatropin.
Growth Hormone Deficiency (GHD)
In children
A child with an inadequate production of growth hormone (reduced or non-existent) may have a normal height and weight at birth, but the child’s physical development following birth is severely impaired.
The under-secretion of human growth hormone during childhood and puberty slows bone growth and teeth development, and also causes the growing plates of the long bones to close before normal height is reached. In addition, other organs of the body fail to grow and the body proportions remain childlike.
Without treatment the child with GHD risks the development of a range of complications, as well as having a short stature.
Turner’s syndrome
Turner’s syndrome is a common genetic defect that affects girls and women and occurs in about one out of every 2,000 to 2,500 female births.
In Turner’s syndrome all or part of one of the two X-chromosomes is missing, but the reason why this happens is not known. This defect can cause a number of physical and medical problems and in some cases creates educational and behavioural concerns.
Characteristics of Turner’s syndrome
As the extent of the defect to the chromosome varies, every case of Turner’s syndrome is individual and each affected girl may have only a few of the possible characteristics that can be associated with the syndrome.
Short stature is a common characteristic of Turner’s syndrome resulting in a decreased final adult height and is generally accompanied by a failure of the ovaries and infertility.
Growth failure in Turner’s syndrome
The reasons for the growth retardation in Turner’s syndrome are not entirely understood, but patients are generally not deficient in growth hormone. The pituitary gland produces adequate amounts but the long bones do not respond.
The growth plates appear to be resistant to the action of the body’s GH, yet the hormone functions normally in controlling metabolism and organ development. By treating with supplemental hGH the resistance can be overcome, creating growth in the long bones. Female hormones may need to be given as well.
Being a genetic problem the affected individual will be faced with the consequences of the syndrome all her life, but can expect to lead a healthy life with appropriate care and treatment.