PTEN tidbit

PTEN is the gene associated with Cowden syndrome, a cancer risk syndrome, associated with colonic polyps, increased head size (macrocephaly), and specifically breast cancer. It has been thought that it was not associated with an increased risk of colon cancer. A study by the Cleveland Clinic, published in the December issue of Gastroenterology, showed an association of increased risk of breast, endometrial, and thyroid cancer most closely associated with the increased large head size. However, their sample had nearly 75% of patients with a large head, as opposed to others which have found an incidence of closer to 25% percent, so there may be an ascertainment bias.

Disclaimer: I got this information through an online journal watch, and don't have access to the full article at this point. Hopefully will be where I can again soon. I do have a certain trust that this journal watch newsletter is well reviewed, so that the studies reported are well conducted. But there is nothing like reading it for yourself.

Also there was an association with significant colonic polyps, which went on to form early colorectal cancer. The researchers suggested that patients with a PTEN mutation should have yearly cancer screenings as early as age 30. Maybe head size should be an adult vital sign, not just a pediatric one, at least in people with a family history of cancer; extremes may be significant.

Why is PTEN related to psychological maturity? Because some mutations can also result in a syndrome called BRR, and a couple of other names, including one with my mentor, Zonana(so I like that one the best.) Eventually, we will get rid of the names after the researchers anyway. Probably before I get my syndrome with my friend Boomer, so we could call it Boomer Pant syndrome. Ah well.

Back to BRR: in this syndrome it is associated with a big head, mental retardation, and spots on the penis, hence it is mostly seen in men. Those spots are easily recognized by a trained geneticist, and mental retardation is more common in men because of other genetic factors. So is there also a behavioral phenotype to other PTEN mutations? That is what I will be researching and reporting on next.

Do we have norms of head size for all ethnic groups? African-American may have larger or smaller norms (ee--that might depend on tribe if you are in Africa...), American Indian likewise. Asians might have smaller heads, being over all smaller people. I know that there are some ethnic charts; just keep it in mind when doing the measurements. Size does have to do with brain development, but other factors are more specific--mental retardation can occur with both micro and macrocephaly and with a normal size head.