About 2 months ago I had wrote a very brief, superficial post on the multiple types of pathologies that would lead a person to develop extreme stature. It was entitled “A List Of The Types Of Disorders And Pathologies Which Can Cause Overgrowth, Excessive Height, And Gigantism”
This time I would find a more extensive page that goes much deeper into the medical science of the multiple causes for extremely tall stature from Endotext.org. This page seems to focus much more on the gigantism developed from growth hormone excess.
The full page seems to be a page dedicated to gigantism as a general topic. The term gigantism refers to extreme large stature and physical size.
Let’s understand that when we are talking about stature and size, we are talking about height, not weight. Weight is something that can easily fluctuate and it seems that many americans can’t seem to stop getting bigger from increasing their weight. We are talking about height.
The way that the term gigantism is also defined is to assume that the cause or the process of gigantism starts in childhood or adolescence, while the growth plates are still open. Although the term gigantism is most often used to talk about growth hormone excess, it also is applied to non-hormonal causes of overgrowth in children.
Growth Hormone Excess
The link between gigantism and growth hormone excess was noticed even in the 19th century when giants that were big since childhood had their head, face, hands, and feet keep on getting larger in size in adulthood. The enlargement of these attributes would be termed acromegaly. Acromegaly has low rates of incidence around 3 per million people. As for growth hormone excess in childhood, that only occurs in a few hundred people. So Acromegaly and gigantism are two different things although they have some things in common. The first is that people who have acromegaly have around 10% chance of being tall statured. The acromegaly is deduced to be just the continual result of what the human body does after epiphyseal growth plate fusion when that individual also suffered from growth hormone excess giving them the tall stature. It seems that increased rate of growth hormone release is sporadic and there may be also a genetic predisposition for this type of disorder in some families.
Under the table for Etiologies of Growth Hormone Excess
- Hypothalamic/Pituitary GH excess
- Ectopic GH excess
- Neurofibromatosis – I
- McCune Albright Syndrome
- Multiple Endocrine Neoplasia Type-1
- Carney Complex
- Familial Somatotrophinomas
- Sotos Syndrome
- Beckwith-Wiedemann Syndrome
- Simpson-Golabi-Behmel Syndrome
- Weaver Syndrome
All of these syndromes and pathologies seem to cause the adolescent who is still growing to have a higher rate of excess growth ending up with tall stature than a person without that pathology.
When reading through the sections to see whether the different causes have anything in common, the main thing I noticed is that familial somatotrophinomas have a 100% chance of gigantism occuring. The term “familial somatotrophinomas is defined on the reference cite as “the development of GH hypersecretion in two or more members of a family that does not exhibit features of MEN-1 or CNC”. The other type of disorder that lead to high percentage of gigantism occurence is the multiple endocrine neoplasia type-1.
For the last four types of syndromes listed, they seem to cause not just postnatal excess growth but also prenatal excess growth. The occurence of macrocephaly is really high. Macroglossia is also a symptom of Bethwith Syndrome and Simpson Syndrome. For the mode of inheritance, all of the last 4 types of pathologies are extremely rare familial cases and sporadic.