Immunity to Disease and a Person's Height, Connected?

According to an article on ScienceNow some human populations are categorized as pygmy. A pygmy population have multiple differences and similarities including that they are are small in stature, plus they make their homes in tropic forests. Where they hunt and tend to die at very young ages mostly due to diseases that flourish in the hot wet environment. Leading scientists believe some of the reasons why pygmies have developed their small stature is due to how nimbly they are able to navigate the jungle.  Also there smallness may help them expend heat. One of the other theories that scientists have developed is they may stop growing after puberty, so that they have the maximum amount of time to produce offspring. However, with all of these theories there is no real genetic evidence to support any of them. Regardless a new study has seen a location where immunity and height are connected.

Also the study showed that short stature is a result of other traits and not a direct result of natural selection. The study consisted of Sarah Tishkoff from the University of Pennsylvania and her other colleagues examined the complete genome of 70 different people from a total of three different pygmy groups hailing from Cameroon. They also examined another 60 people from Bantu groups as well. The goal of study was to locate single-nucleotide polymorphisms variants. These variants were hopefully going to show unique traits isolated to  pygmies. What they were able to find were variants in genes that involved some of the brain's chemical messengers. One specifically was thyrotropin-releasing hormone, which was interesting since pygmies seem to not contract thyroid problems. Another interesting one was one called CISH, which shuts down a intergral receptor which controls the flow of growth hormone.  CISH also showed to have an affect on a persons ability to contract diseases like malaria and tuberculosis. Due to this evidence it would seem the height and immunity are connected. Sarah doesn't believe that other hypothesis's are wrong, however she wants everyone to understand that picture is more complex then originally thought.