Dear Jackay,

Thank you for posting your query.

I have gone through the question and all the reports. It is obvious that on first thoughts, he has a GH deficiency ... but it is not that simple. This is because the secretion of GH varies throughout the day. At times, even a normal person may show a level that is zero. It is more important to conduct a test for GH after stimulating the child with one of the two following medicines: the first is Insulin, and the second is clonidine. After giving one of these drugs to a person, the GH secretion rises and reaches a peak within 45 to 60 minutes. The test with Insulin is the gold standard, but must be done in a hospital or day-care setting under the supervision of a XXXXXXX pediatrician or a pediatric endocrinologist.

Interpreting the GH levels from a fasting sample will overestimate the problem of GH deficiency and is not recommended.

All the other reports seem to be normal.

Now, coming to the issue of what this can be if it is not GH deficiency. There are two separate entities that may cause stunting and failure to grow. In the first, the child follows in the footsteps of his parent - any one of them, and when we enquire with the parents, they tell us that they were just like the child is when they were of the same age as the child is today. This is called "familial" growth delay.

The second reason is what is termed as "constitutional" delay. In this, there is no positive family history, and yet, the child undergrows. Some of these cases later turn out to have GH related problems, and even if they don't have a detectable GH deficiency, they may show good results with GH therapy.

Please speak to Dr. XXXXXXX about a stimulated GH study for a final answer to this conundrum.

With regards,

Dr. Taher Kagalwala,

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Dear Jackay,

IGF or Insulin-like Growth Factor is a generic term used to describe proteins secreted by bone and other tissues in response to the pulse secretion of GH ( Growth Hormone ). IGF 1 is the most important and commonly measured protein from among this group. It is IGF which actually mediates the functions of GH at the tissue level. In the blood, IGF is bound to IGF-binding protein, or IGFBP, and measuring this along with IGF 1 provides one with a very good diagnostic sensitivity of the lack of GH function.

Thus, what you say in your follow-up is right. However, even a normal IGF does not totally rule out GH deficiency. That is exactly why I asked you to go in for the test of GH estimation after stimulation. That will either confirm or rule out GH deficiency. As I said earlier, testing with Insulin is the standard. There are other medications that have also been used, of which the most popular is Clonidine, though there are others like L-dopa which can be used too.

Before this, it might also be prudent to do Thyroid function tests and serum lipid levels. The first test is to rule out Hypothyroidism as a cause for the growth retardation; the second test is done as a test to support the diagnosis of GH deficiency, as such patients have a different profile of serum lipids.

It would be of great help to me if you may please take a photograph of your child and upload it.
You have a feature to upload the reports / image by yourself at the right side of the query page, please utilize that so that I can answer your queries better. You can also mail it to me at YYYY@YYYY with subject as 'Attention to Dr. Taher Kagalwala'.

Awaiting your response.

Regards,

Dr Taher

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Dear Jackay,

I have seen your reports earlier, and believe me, they are NOT portents of any bad news for your son with regard to endocrine problems. Such variations are normal, and will occur due to inter-personal differences, lab standards selected by the lab where your tests are done, and because of XXXXXXX changes in the individual's body. For practical purposes, they can be taken as normal or non-significant.

I have re-checked the reports PDF and find that thyroid tests have already been done and shown to be normal. That is one problem out of the way. I missed this when answering to you earlier, for which I apologise.

Okay, so we have no thyroid problem, the bone age is retarded, the IGF 1 is normal, and the child's all other reports seem to be normal.

Are there other conditions that can cause such a lot of growth delay? Actually, yes, but each of these have some other easily found history or exam findings. They include "renal tubular acidosis" and "celiac disease", both extremely rare and esoteric. In the former, there would be rickets - bent bones and deformities, while the latter would present with gastrointestinal complaints such as large, bulky stools or diarrhoea.

With regards,

Dr. Taher

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