Has your mom ever told you not to watch TV too closely? Have you been told as a child that reading too much (or cross-stitching too much) will hurt your eyes? That’s not too far out an idea, at all.

Severe myopia or nearsightnedness. Image: Flickr

Myopia or nearsightedness is a condition where one has trouble seeing objects that are farther away. Symptoms, usually developing in early childhood and teen years include squinting when trying to concentrate on an object far away, or holding an object very close to the face (to read, or to see it clearer). The person may want to sit very near the TV or computer close, and prefer to sit in the front of the class.

But does this mean that close-work and intensive reading cause eye problems?

Studies have shown that myopia is more common in some populations, such as the Ashkenazi Jews and Taiwanese where intensive studying and reading are encouraged; and in Singapore where certain jobs are visually-demanding. So certain kinds of exposures and tasks may contribute to myopia. BUT this is only part of the story.

Genes also play a major part, and plenty of studies already show that myopia is passed from parents to children. For example, myopia is more common in children of myopic parents than children of non-myopic parents.

So if scientists can identify myopia genes, treatments can specifically be created for children who are genetically more likely to develop myopia. Perhaps drug or gene therapies can even help make the condition less severe.

Tomorrow, we’ll look at some of the promising findings that point to genetic  factors of myopia.

image: Flickr

For all of man’s scientific prowess and evolutionary advancement, we are the helpless victims of this sneaky little villain. Cold viruses have very few genes, so they have one purpose and one alone - to make our lives miserable!

So we hack, snort, sneeze and feel awful until this prokaryote decides it has enough of us. There is no cure. We can treat the symptoms, sure, but we’re not fighting the virus. We’re simply "letting it run its course" and that really sucks, right? Here is man, the mighty Goliath, and this puny David of a virus swings at us and down we go, crying for our mommies.

The latest research found that it’s not the rhinovirus that causes the cold symptoms. Rather our immune response goes into "overdrive" because this viral infection. Great. The scientists believe the ideal treatment should "maintain body’s natural antiviral response while normalizing the inflammatory response."

Cool. Meantime, excuse me for the infrequent posting while my body goes into overdrive as the cold virus continues to taunt and bring havoc to my existence.

image: Wikimedia

It’s the Sunday edition of Genetics and Health so let’s sum up some of the genetic research and news that came up this week.

A grand rounds lecture "Molecular Genetics of Colorectal Cancer" by Vincent Yang presents an overview on the role of genes in colorectal carcinoma, and shares initial findings on a cell cycle modulator gene.

The NY Times article, "Man Who Helped Set the Stage for Nobel-Winning Work Has Left Science" profiles Dr. Douglas C. Prasher, the scientist who provided the essential piece of evidence that helped the work of Nobel Price Chemistry winners Roger Y. Tsien and Martin Chalfie. You’ll be surprised to find out Dr. Prasher’s latest employment.

A "pleasure" gene is behind an obese person’s insatiable desire to eat more.

The Personal Genome Project is open for business and it’s looking for volunteers agree to make public their medical history AND DNA sequence. PGP is a nonprofit, volunteer database project by Harvard University.

  The gene for male-pattern baldness (androgen receptor) has traditionally been linked to the X chromosome which means mom passes it on to her sons. Now, two new independent studies published yesterday at the Nature Genetics identified association between hair loss and chromosome 20.

A genome-wide association study (GWAS) for male-pattern baldness, or androgenetic alopecia, identified a new association at chromosome 20p11.22, between the PAX1 and FOXA2 genes, and confirmed a previous association with the gene encoding the androgen receptor in the X. Tim Spector and colleagues found that 1 in 7 men carry both the chromosome X and chromosome 20 variants, and that these men have a 7-fold risk of having pattern baldness.

Another independent GWAS found overwhelming evidence for five SNPs on chromosome 20p11 and confirmed the results on X, but did not find any gene-gene interaction between the two regions, suggesting that the locus on chromosome 20 may play an as-yet unidentified role in hair loss. These new results now show that more than one gene is responsible for hair loss and explains why there are similarities between a balding father and his son.

image used with permission by Newscom

A new study found that premature ejaculation is not purely psychological. Genetics has a lot to do with it.

Scientists from Utrecht University in the Netherlands studied 89 Dutch men who had "primary premature ejaculation", which means they suffered from it from their first sexual contact. They were compared with 92 men who had no such history. In men with premature ejaculation, the serotonin was deficient in the area of the brain that controls ejaculation.

Serotonin is a neurotransmitter that controls body temperature, sleep, sexual activity, appetite and emotions such as anger, aggression and mood. A common polymorphism (5HTTLPR) within the promoter region of the serotonin transporter gene has been shown to influence the amount and activity of serotonin, so the authors postulate that 5HTTLPR may control the rapidity of ejaculation. In the study, men who had the LL genotype of 5HTTLPR ejaculated twice as rapidly as those who had the alternate genotype (SS) or were heterozygous (SL).

The take home message: The research contradicts the common idea that the primary form of premature ejaculation is a psychological disorder. With further study and confirmation, the authors hope gene therapy against premature ejaculation would be possible in the future.

The study will be published online this week in the Journal of Sexual Medicine.

via Science Daily

Or so suggests this study, so I write this with raised eyebrows.

Scientists have identified a common genetic variation that appears to weaken a man’s ability to emotionally attach to one partner.

Findings from the Karolinska Institute in Sweden found that men with relationship and communication problems carry a variation in the gene that codes for vasopressin 1a receptor subtype, a hormone involved in brain signaling and said to influence monogamy in animals. Allele 334 of the vasopressin gene was associated with lower scores on partner bonding and greater odds of marital conflict.

Among men either with no copies or just one copy of the 334 allele, 15 to 16 percent reported a marital crisis in the past year. However, when men had two copies of the 334 allele, the odds of marital crisis doubled, to 34 percent.

Interesting, isn’t it. Of course the researchers qualify these results with a caution that relationship problems are not solely caused by genes but several other behavioral factors.

So ladies and gents, what do you think?  Should men get tested for this allele? Would testing help deal with the issues?

The study appears in the Proceedings of the National Academy of Sciences.

Enlarged hearts are found often, but not exclusively, in those who are obese, have diabetes or high blood pressure. People with none of these underlying problems can be affected, as can elite athletes.  For example, a post-mortem diagnosed the problem in Cameroon football midfielder Marc-Vivien Foe, who died in 2003 after collapsing during an international match in France. Elite runner Olympic hopeful Ryan Shay died of complications involving an enlarged heart - the very condition that made him a great runner.

An international  research team headed up by Imperial College, UK say they have for the first time linked enlarged hearts with a gene, osteoglycin (Ogn).

Work carried out on rodents and some 30 humans indicated that Ogn - which has never before been linked with heart function - regulated the growth of the heart’s main pumping chamber, its left ventricle.  When this gene behaves abnormally the heart can become enlarged, putting the person at an increased risk of common heart diseases and heart attacks.

For further information, click on:

http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_29-4-2008-13-31-10

Elaine Warburton  www.geneticsandhealth.com

Thank you to Jennifer Texada at MD Anderson for bringing this great cancer treatment discovery to my attention….

(Image courtesy Introgen Therapeutics)

A gene therapy invented at The University of Texas M. D. Anderson Cancer Center is the first to succeed in a U.S. phase III clinical trial for cancer.  Introgen Therapeutics, Inc a spin out from MD Anderson, reported results of its phase III trial of Advexin, a modified adenovirus that expresses the tumor-suppressing gene p53, for end-stage head and neck cancer.

The p53 gene is inactivated in many types of cancer. Its normal role is to halt the division of a defective cell and then force the cell to kill itself.

“Cells become cancerous because p53 no longer functions. Restoring p53 works unlike any current cancer treatment because it treats the cancer genome,”said Jack Roth, M.D., professor in M. D. Anderson’s Department of Thoracic & Cardiovascular Surgery, who invented the drug and co-founded Introgen.

The trial showed that p53 expression in the patient’s tumor before treatment is a reliable biomarker for how to treat head and neck cancer. Patients with a favorable p53 profile who received Advexin had an average survival of just over 7 months, compared with just under 3 months for those whose tumor expressed high levels of mutant p53 before treatment. Patients with this unfavorable profile were better off taking the chemotherapy drug methotrexate, resulting in n average survival of just under 6 months.

“The important finding is that patients who benefit from treatment can be identified with the p53 biomarker. The biomarker will enable physicians to personalize treatment,” said Roth.

Better Quality of Life

Patients treated with Advexin experienced far fewer harmful side effects such as pneumonia than those who received methotrexate. The incidence of inflammation of the mouth lining and a decrease in white blood cells, for example, both dropped to zero for those receiving Advexin.

“That certainly results in a better quality of life,” Roth noted, which makes sense because p53 does not cause problems in normal cells.

Roth’s lab has been developing gene therapy for cancer since 1990. “We wanted to go beyond conventional treatment, because most of those treatments were not very effective,” Roth said. “Surgery and radiation are limited to the local tumor and once given, it’s very hard to repeat those therapies.  Chemotherapy inhibits DNA replication, but it also interferes with normal cells.”

Elaine Warburton  www.geneticsandhealth.com

Mutations in a gene called FIGLA cause premature ovarian failure in at least 1% of women who suffer from the disorder, said researchers from Baylor College of Medicine in Houston and Shandong University in China in a report that appears online in the American Journal of Human Genetics. Premature ovarian failure, which means that the ovaries lose function before age 40, not only causes infertility but also bone and heart problems.  Ovarian reserves are important for women’s health.

FIGLA is one of four transcription factors found to control the differentiation of egg cells early in development. Transcription factors govern the activity of genes, turning them off and on and modulating the extent to which they are active.  The other genes involved include NOBOX, GDF9 and BMP 15.  Mutations in these can lead to premature ovarian failure as well.

“We hope to define majority of the genes that are part of the cellular pathways involved in ovarian failure,”said Dr. Aleksandar Rajkovic, associate professor of obstetrics and gynecology at BCM and senior author of the paper.

“Ideally in the future we will offer a test to women to look at all the genes involved in premature ovarian failure.”

He anticipates that a gene chip would be helpful in such diagnosis, which can help in counseling women or their children about the risk of early ovarian failure.

For up to date information on fertility and women’s health, visit my b5 friend Gabrielle at www.fertilitynotes.com

Elaine Warburton  www.geneticsandhealth.com

(Image credit www.about.com) 

A University of Carolina study monitoring 1200 newborns from the ‘Isle of Wight cohort’ found that first borns were more likely to carry a gene variant which raised their risk of developing an allergy before the age of 10.  The study suggested that a first born experienced different conditions in the uterus from subsequent siblings.

The researchers measured levels of an antibody called Immunoglobulin E (IgE) in the babies’ umbilical cord blood.  This is known to play a key role in the development of allergic responses.   First born babies were more likely to have high levels of IgE, and those that did were also more likely to show signs of an allergic response when they were subsequently tested, using a skin prick test, at the age of four and ten.

The researchers also believe they may have pinned down the genetics behind the difference to variations in a gene called IL13, which controls production of a stress hormone called a cytokine, which in turn influences levels of IgE. They found that first born children were more likely to carry a variant of IL13 which raises levels of the cytokine, and in turn IgE.

The researchers believe that birth order may affect expression of the gene during the foetal differentiation and development.

Lead researcher Dr Wilfried Karmaus said:

“We were not surprised that birth order had an effect on the development of the immune system, but were surprised that this interaction persisted at least through age ten … Our findings add to the evidence that allergic reactions are programmed during pregnancy and then effect the disease in later life. … This finding may partially account for the increasing prevalence of asthma and allergies in children in the last 30 years, primarily seen in the western world, as developed nations’ birthrates continue to decline.”

He said that if a way to modify those conditions could be found to make them more like those experienced by later born children, then potentially it might be possible to prevent 20-30% of all cases of asthma and allergy.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2366045

Elaine Warburton  www.geneticsandhealth.com