Short Stature and Growth Problem

Miles Yu, MD
Pediatric Endocrinology, UNC Hospital

         Most parents are always care about their children’ growth. Are they too short or are they too tall? Usually there is not much problem if a child grows too tall. On the other hands, parents will be very concerned if their child is growing not as tall as expected. So, what is the problem of being short? Has anybody short have any growth problem? What can we do about it?

What is short stature?

        Short stature is a medical term giving to any person whose statural height is 2 standard deviation or more below the average for persons of same age and sex. This also means that this person’s height would be less than 5% of standard growth curve. In general, any child or adolescent who is significant shorter than his (her) peers should be considered to have short stature.

What ‘s the problem for short people?

        We all understand being short per se is not a problem. Shortness is not necessary prevent you from becoming a successful person. Look at Napoleon, look at Deng Xiaoping, to name a few. In real life, you still don’t want your son (or daughter) to be much shorter than his (her) peers. Why? Because you know that life could be harsh sometimes for those of short persons. Just observe carefully how those short school-age kids are treated by others on/off class. Besides, short stature sometimes may have growth problem caused by some underline conditions or diseases.

What are the causes for short stature?

        Fortunately, most of short persons have no growth problem or medical conditions. Generally, any body that grows within 5% to 95% on growth curve is defined as normal. Then most of NBA players are abnormal, since they are taller than 95%. Most of them are normal, as you can understand. Similar rule applies to those who are shorter than 5%. We can label most of them (people grow outside 5% to 95%) as normal variants. The following are many of conditions that are related to short stature:

1) Genetic short stature (or familial short stature)

        As it’s name implied, the shortness of a child is inherited from his (her) parents.  Just like we Chinese always say, dragon is born to dragon, phoenix is born to phoenix, short kid is born to short parents. At birth children with genetic short stature are not necessary small. Their shortness usually becomes apparent after 1-2 years old. After that they actually grow at constant normal rate. Their statural height is always at the bottom or below the curve but parallel to it. Characteristically, they enter into puberty at the same time as others. This is one of most common type for short stature.

        2) Constitutional delay of growth

        Similar to the condition above mentioned, children with constitutional delay are born with normal size. Their statural growth falls below 5 % of growth curve after 1-2 years of age. Because they usually enter puberty later than their peers, their growth and development are lagged further behind. These are the most children evaluated by medical doctors. In spite of problems or concerns that may occur in some of these children, most of them will eventually reach their normal final adult height. This is another very common cause of short stature. There may be a positive family history of pubertal delay.

        3) Nutritional deficiency

        Although they may also be short, children with nutritional deficiency characteristically are more problematic in weight gain than height growth. They are usually diagnosed as failure to thrive. This is also relatively common but sometimes unrecognized problem. This type can be subdivided into 3 categories: a) Inadequate intake: It can be seen in some hyperactive but healthy children who are not interested in eating, or they may use eating as power to control their anxious but unskillful parents or care takers. It may also seen in children living in families with improper feeding routine or dietary restriction. Rarely, it may be seen in children with some conditions that interfering their eating such as oral motor dysfunction or severe cleft palate. b) Malabsorption: Evan having enough food intake, children may have some conditions that interfering absorption of nutrients. There are many conditions should be considered to cause malabsorption such as milk allergy, celiac disease, cystic fibrosis etc. c) High carbolic consumption: It is commonly seen in children with chronic diseases such as congenital heart disease, tuberculosis or chronic renal failure, to name a few.

        4) Precocious puberty

        Actually children with this condition have tall stature initially.  However, because of the earlier maturation of bone, their ceasing growth too early that can result in short final adult height. It can be caused by some underline diseases such as tumor growth in brain, although majority of have no known causes.

        5) Dysmorphic syndromes or genetic diseases

        Although they are rare, there are vast numbers of syndromes and genetic diseases that may associated with short stature. Whether it can be Down syndrome, Turner syndrome, or Noonan syndrome, hydrocondrodysplasia. With the advancement of molecular diagnostic techniques, there are more and more syndromes and genetic diseases can be identified. Any short child with 2 or more abnormal facial or body features should be suspected to have a dysmorphic syndrome or genetic disease, especially when unusual features occur in other family members.

        6) Endocrine diseases (or hormonal problems)

        There are many endocrine diseases that can cause short stature: hypothyroidism, Cushing syndrome, growth hormone deficiency, or rickets, just list a few. Although they are also rare, if recognized early, they can be properly diagnosed and easily treated.

        7) Others

        There are many other conditions that may be associated with short stature. They can occur alone or in many cases, occur in combination with other problems. For example, psychosocial deprivation may cause growth retardation in combination with inadequate food intake and or chronic diseases.

What can be done?

        As a parent, if your child is significant shorter than his (her) peers or if  his (her) growth rate has decreased, you need to bring him (her) to your primary care doctor to be evaluated. You need to prepare the following information:

1)       Child’s history:

All the information including birth history, his (her) growth history, his (her) food intake, any related symptom or diseases, and his (her) past and current medication.

2)       Family history:

        The growth and developmental histories for siblings, all the parents and grandparents. Any history of family member who has the condition or been diagnosed with a disease associated with short stature. Other family members’ developmental history, particularly the history of puberty.

        Your doctor will perform a thorough physical examine and some screening laboratory tests or X-rays as needed. Then your doctor will decide whether a referral to a specialist is necessary.

What are the treatments:

        The treatment for short stature is depended on the nature of causes. If your child has familial short stature, no treatment is necessary.

        Generally, constitutional delay of growth requires no treatment as well since time will cure it. But if child’s puberty is delayed to a such degree that it causes a significant psychologic problem which interferes his (her) normal life, the endocrinologist sometimes may try to give him (her) a low dose of sex hormone to “kick off” the child’s puberty.

        If your child has nutritional deficiency, you should work with nutritionist (dietitian) and /or other necessary service provider to correct the problem.

        For precocious puberty, there is a medication available to stall the pubertal progression. After the treatment, the final normal adult height can be preserved.

        If your child has hypothyroidism, he (she) should be treated with thyroid hormone replacement. The treatment is inexpensive, simple, and very effective.

        If your child has growth hormone deficiency, he (she) should be treated with growth hormone replacement. The treatment is straightforward and effective. But the cost is high (about $10k/year for a 10 years old child).  Growth hormone is approved for use in growth promotion for short children with condition other than hormone deficiency, such as Turner syndrome and chronic renal failure. It is predicted that GH will be approved for many other conditions in the future.

        If your child’s shortness is caused by combination factors, it may need to utilize a team of service providers, which may include endocrinologist, nutritionist, psychiatrist, and social worker.

        In summary, if your child’s height is significant shorter than his (her) peers and his genetic potential, it is worthy to have your child evaluated by his medical doctor in order to rule out some conditions which might be easily corrected.