Laron syndrome (also referred to as Growth Hormone Insensitivity Syndrome, Pituitary Dwarfism II, and Growth Hormone Receptor Deficiency) is an autosomal recessive disorder (i.e., you have to have two copies of the mutated gene–one from mom and one from dad) caused by a mutation on chromosome 5 that results in an individual being non-responsive to growth hormone. Those that are non-responsive fail to produce insulin-like growth factor I, which ultimately leads to short stature.
Jaime Guevara-Aguirre stands with some of the people who took part in his study of Laron syndrome in Ecuador. Photo credit: Valter Longo.
NPR reports on a study in Ecuador that shows that this mutation, while causing Laron syndrome, seems to prevent diseases such as diabetes and cancer (diseases typically, though not exclusively, associated with ageing). What is super interesting is that a mutation similar to Laron syndrome is known to extend lifespans in other organisms like yeast and worms. From the interview with researcher Valter Longo:
The mutation seems to prevent diabetes by allowing people to get by on very low levels of insulin, Longo says. It wards off cancer by reducing DNA damage in cells, and helping to eliminate abnormal cells. You might expect all this protection would allow the small people in Ecuador to live longer than their taller relatives, Longo says. But that’s not what he found. “The majority of them die of strange causes,” he says, including alcohol abuse and accidents. These are things that are preventable and not caused by a disease, Longo says. Subtract these deaths, he says, and it looks like people with Laron syndrome really would live longer than their relatives. Longo says his study suggests that a whole group of people might be able to lower their risk of cancer and diabetes if they could lower their levels of growth hormone, or change the body’s response to it. The benefit would probably be greatest in people who have unusually high levels of the hormone, he says.
Connecting to a previous post on the blog, scientists also suggest that people with pituitary tumors (a similar situation to these growth hormone abnormalities) may also be at greater risk for cancer (see Irish giants and DNA)
The 2011 Harriet-Elliott Lecture Series blog 
My mom was just telling me about this yesterday. For a long time now I’ve believed that everyone, provided they don’t die of some other natural or unnatural cause first, will eventually contract some form of cancer. For some reason it never occurred to me that it could be related to growth hormones, but it makes sense. I think it’s poetic and fair that, in return for something which usually causes them to be mocked, these small people (is that the correct term?) are essentially immune to cancer. This seems like it might be some sort of huge breakthrough in the search for the “cure for cancer,” but it doesn’t sound like it can be used to rid people of existing cases, and that it can only be used as a preventative measure. It also raises so many questions in my mind that I can only wonder at just how far we still have to go.
This is very interesting, what may seem like a maladaptive trait in fact is in fact preventing some very serious diseases sort of similar to a person who is heterozygous for Sickle Cell Anemia and immune to Malaria. What I’d like to know more about is what Longo calls ‘strange causes’ for death, does perhaps this mutation cause an increase in reckless behavior? What would be the tradeoffs in this situation, if a group were to lower their levels of growth hormone it could affect their personality and society as a whole but changing customs and culture in a major way. This is a one of those cases where having genes mapped and finding out what you’re carrying may play a major role in if you have kids or not, because this mutation requires both parent to provide the mutated-gene. Parents who get tested may then choose to reevaluate their plans for children based on the results similar to Jewish couples at risk of having children who could suffer from Tay Saks disease.
This article was interesting as well… I had not heard of this disease before but I think its facinating that this disease seems to prevent diseases like cancer and that there is a mutation similar to Laron syndrome that is known to extend lifespans.