Prof Emeritus Savage explaining a graph on human growth during his presentation to the media. Photos: The Star/Muhamad Shahril Rosli
Often times when we meet someone who is short, we are likely to think that it’s just the luck of their genes.
Even if they are much shorter than average, we are likely to brush it off as just being their lot in life.
And that is a problem as some children suffering from short stature can actually be treated.
“In a sense, we are fighting for recognition because growth disorders are usually not life-threatening, so they don’t get as much immediate recognition and publicity as, for example, cancer, diabetes and problems with neonatal disorders,” says University of London, United Kingdom, consultant paediatric endocrinologist Prof Emeritus Dr Martin Savage.
He explains that the growth meant here refers to height, or linear growth.
“Short stature is not always recognised or perceived by the general public to be a problem, and a problem that can be successfully treated in some circumstances,” he adds.
Universiti Kebangsaan Malaysia Medical Centre’s Paediatric Endocrine Unit head Prof Dr Wu Loo Ling agrees.
Prof Wu stresses that patients and their family need to start treatment as early as possible and be compliant to it in order to reap the maximum benefits within the limited period of growth the child has.
“There are a lot of people out there who can be helped, and yet, they are not getting help.
“We actually lack awareness – even among the doctors – among the public, the parents, even the schools; they are very complacent, they think that we are just small people,” she says.
Among the problematic attitudes she has encountered are that the child looks healthy despite being unusually short; that being petite is cute; that the child still has many years to catch up in height, especially when they hit puberty; and that the child is a picky eater and as long as they improve their appetite or take supplements or traditional medicine, they will be fine.
Doctor-shopping is another problem, she says, where parents of an affected child go from doctor to doctor hoping that the next one will tell them what they want to hear.
However, the senior consultant paediatric endocrinologist and diabetologist warns that these attitudes will only result in delayed referral to the right specialist, by which time the child might have missed the window of opportunity for treatment.
What is short?
Our period of growth starts at birth and stops once we hit our mid to late teens – on the average, 16 years of age for females and 18 years for males.
Explains Prof Emeritus Savage, who also practices at The London Clinic Centre for Endocrinology: “Basically, children grow because in their long bones, which are the bones of the arms, the legs and the spine, there is a layer of cartilage, which is the site of active growth.
“This is called the growth plate. And this growth plate is made up of cartilage cells called chondrocytes.
“Essentially, a child grows by these cartilage cells developing, differentiating, expanding, and eventually becoming formed as bone.”
The cells in the growth plate are triggered by growth hormones, which are produced by our pituitary gland.
“The growth hormone circulates around the body until it eventually comes to the growth plate where it is transformed to another hormone called IGF-1 – insulin growth factor-1 – and it is IGF-1 that actually stimulates the growth plate to expand and grow,” adds Prof Emeritus Savage.
Our period of growth ends when our growth plates close and are replaced by bone.
For those with treatable growth disorders, this represents the end of the window of opportunity for treatment.
There are three general causes of short stature: variants of normal growth, endocrine causes and non-endocrine disorders, says Prof Emeritus Savage.
Variants of normal growth include children that are otherwise healthy, but not growing as fast as the rest of their age group, as well as children whose parents are naturally short.
Non-endocrine disorders include chronic conditions like malnutrition and renal failure, chromosomal defects like Turner syndrome, as well as intra-uterine growth retardation (IUGR) and small for gestational age (SGA).
And endocrine causes include growth hormone deficiency and resistance, hypothyroidism and Cushing’s syndrome, among others.
Short stature, Prof Emeritus Savage explains, is actually a statistical definition.
It is when a child’s height is more than two standard deviations from the mean height of children their age, sex and pubertal stage.
Says Prof Wu: “Any child who has fallen short of the normal centile – below the third centile, as Prof Savage said – the shorter the child is, the more likely you are to find a pathological condition in this person.
“So any short child, especially a very short one, or those children who are slowly deviating from their centile, are likely to be abnormal.
“So they must be recognised, evaluated and investigated, so that the appropriate treatment can be given.”
Treatment for three
According to the Health Ministry’s 2010 clinical practice guidelines on the subject, the use of recombinant growth hormone therapy is indicated in three conditions: growth hormone deficiency, SGA and Turner syndrome.
Argentinian footballer Lionel Messi was diagnosed with idiopathic short stature as a child and received recombinant growth hormone therapy to achieve his current height. Photo: AFP
Certain countries, like the United States, have also approved the therapy for use in children with chronic renal insufficiency whose height is affected (up to one-third of such patients) and idiopathic short stature, according to Prof Emeritus Savage.
Growth hormone deficiency, as indicated by its name, means that the body is not producing enough growth hormone due to a problem with the pituitary gland.
The problem can be present from birth (congenital), or a result of a tumour, infection, radiation or a severe head injury.
Says Prof Wu: “There are a lot of metabolic effects from the lack of growth hormone – this person is not just short, but also not well.”
She explains that growth hormone deficiency results in the deposition of fat around the abdomen, lack of muscle mass, poor stamina and poor bone health, among others.
In this condition, treatment needs to be initiated as soon as possible after diagnosis.
Meanwhile, SGA means that the baby is born with a length and/or weight that is below the normal range for their gestational age.
This occurs in about 5% of newborns.
“We now know that a proportion of these babies do not catch up – they stay small. They become small children and small adults,” says Prof Emeritus Savage.
As some SGA children do catch up in growth after a while, treatment is only started if the child does not catch up after four years of age.
In the case of Turner syndrome, which affects only females, patients are born with only one fully-functional X chromosome.
“Just because they have Turner syndrome, they are already 20%-25% shorter than they would have been without Turner syndrome. That’s almost one foot!” says Prof Wu.
This syndrome can be diagnosed at birth, and the affected children – one in 2,500 female babies – need to be monitored for their growth.
According to Prof Wu, growth hormone therapy is initiated as soon as a drop in their height centile is observed, as this means that their body is no longer able to supply the adequate amount of growth hormone.
She also notes that those who are SGA and those who have Turner syndrome are normal people, saying: “They have normal IQs, but they are people of low self-esteem because they are very, very short.”
Prof Emeritus Savage agrees: “An adult who is abnormally short has major disadvantages – physical disadvantages, psychological disadvantages, disadvantages in terms of employment, self-esteem, well-being, etc.
“That is what we are trying to avoid (with treatment).”
In Malaysia, recombinant growth hormone therapy is available in a number of public and university hospitals across the country.
According to Prof Wu, the treatment, which is weight-dependent and can come up to RM3,000 a month for a teenager, is not free; however, there are limited public and NGO funds available for deserving patients.
Both Prof Wu and Prof Emeritus Savage were speaking to the media at a roundtable after the SEA Growth Summit organised by pharmaceutical company Novo Nordisk in Kuala Lumpur recently.