Autism, SHANK, and busy highways

Two autism studies in the news. I’ve summarized them at the Thinking Person’s Guide to Autism here. Let’s just say that the headlines, stories, and news releases have hyped yet again. Indeed, the title of this post should’ve been: “Headlines hype, news releases overpromise again in autism research.”

The worst offender is easily, “Proximity to freeways increases autism risk, study finds.” Um, no. The study found that autism rates are higher among people living within 309 meters of freeways. That in no way means that living close to a freeway increases autism risk. It’s a common, basic overinterpretation of correlation and epidemiological conclusions, but it’s really starting to get old. You can read more about the fuzzy definition of “freeway” and “major road” here.

Mitochondrial dysfunction and autism

Beautiful pic of mitochondria

Mitochondria are the powerhouses of the cell, the biology teachers will tell you. These organelles also happen to be likely former bacteria that once were independently living cells, capable of dividing on their own to make new mitochondria. Indeed, they continue to divide by a kind of binary fission as our cells divide, ensuring that a double dose is available for partitioning into the two new cells that result from cell division.

To achieve these feats, mitochondria have their own DNA, their own proteins, and their own protein-making machinery. That means that they also have the potential to undergo genetic mutations that affect the sequence of the proteins their genes encode. Because most of the proteins in mitochondria are mission critical and must function exactly right, the persistence of such mutations is relatively rare. But they do happen, causing disease. One question that has arisen in the study of the causes of autism is whether or not such changes might underlie at least a portion of the cases of this developmental difference.

The high-profile Hannah Poling case

Certainly lending a high profile to this question was the case of Hannah Poling, whose mitochondrial disorder appeared to be linked to her autism symptoms and may have interacted with a bolus of vaccine doses she received, followed by a high fever. Fevers can tax our cellular powerhouses, and if mitochondrial function is already compromised, the high temperatures and extra burden may result in chronic negative outcomes.

Poling’s case brought to the forefront the question of whether or not people with autism might have mitochondrial dysfunction at greater rates. A recent study in the Journal of the American Medical Association (which steadfastly keeps its articles unavailable behind a paywall) has sought to address that question by measuring markers of mitochondrial dysfunction in children with autism and comparing these endpoints with outcomes in children without autism.

Study specifics: “Full-syndrome autism”

The autistic group in the study had what the researchers called “full syndrome autism,” which I take to mean intense symptoms of autism. They used the Autism Diagnostic Inventory-Revised

(ADI-R) and the Autism Diagnostic Observation Schedule (ADOS) to confirm this diagnosis and to ensure as uniform a population among their autistic group as possible. Ultimately, the study included 10 children in this group, recruited consecutively in the clinic based on their fulfillment of the selection criteria. This study was essentially case control, meaning that the control group consisted of 10 non-autistic children, selected to match as closely as possible the demographic characteristics of the autistic group.

The authors report that while only one child among the 10 who were autistic fulfilled the definitive criteria for a mitochondrial respiratory chain disorder, the children with autism were more likely to have indicators of mitochondrial dysfunction.

A problem with pyruvate dehydrogenase (break out your Krebs notes, folks)

Specifically, six out of ten showed lowered levels of activity for one parameter, while eight out of ten showed higher levels than controls for another metabolic endpoint, and two of ten showed higher levels than controls of a third metabolic endpoint. Overall, the results indicated low activity of a mitochondria-specific enzyme, pyruvate dehydrogenase, which is involved in one of the first steps of carbohydrate metabolism that takes place in the mitochondria. Reduced activity of an enzyme anywhere in this process will result in changes in the enzyme’s own products and products further down the pathway and throw off mitochondrial function. Further, half of the autistic group exhibited higher levels of DNA replication, an indicator of cellular stress, more frequently than controls and also had more deletions in their DNA than controls. Statistical analysis suggested that all of these differences were significant.

What does it mean for autism?

Do these findings mean that all or most people with autism have mitochondrial dysfunction? No. The study results do not support that conclusion. Further, the authors themselves list six limitations of the study. These include the possibility that some findings of statistical significance could be in error because of sample size or confounders within the sample and that there were changes in some of the endpoints in the autistic group in both directions. In other words, some autistic children had much higher values than controls, while some had lower values, muddying the meaning of the statistics. The authors note that a study like this one does not allow anyone to draw conclusions about a cause-and-effect association between autism and mitochondria, and they urge caution with regard to generalizing the findings to a larger population.

If there is an association, questions arise from that conclusion. Does mitochondrial dysfunction underlie autism, producing autistic-like symptoms, as some argued in the Hannah Poling case? Or, do autistic manifestations such as anxiety or high stress or some other autism-related factor influence the mitochondria?

Chickens, eggs, MRI, mitochondria, autism

As interesting as both of these recent autism-related studies are, we still have the “Which came first” question to deal with. Did autism cause the brain or mitochondrial differences, or did the brain or mitochondrial differences trigger the autism? Right now, these chicken-and-egg questions may not matter as much as the findings do for helping to identify autism more specifically and addressing some of its negative aspects. Regardless of your stance on neurodiversity or vaccine or acceptance or cure or the in-betweens where most of us fall, it would be difficult to argue that a mitochondrial dysfunction shouldn’t be identified and ameliorated or that an awareness of brain structure differences won’t lead to useful information about what drives autism behaviors.

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Note: More lay-accessible versions of this post and the previous post are available at BlogHer.

The cooperative, semi-suicidal blob lurking beneath the cow pasture

Aggregating Dictyostelium discoideum; photo from a series available at Wikimedia Commons

Amoebae gone to pasture

Timeline, 2009: Lurking beneath the soil and cow patties of a southeast Texas cow pasture, the cellular slime mold cloned itself and cloned itself again until it was about 40 feet across, billions of cells dense. The thing is, this enormous creature was really neither a slime nor a mold, but a group of social microbes, amoebas that were all exactly identical to one another.

It’s a cell, it’s a colony, it’s…a multicellular organism!

No one is quite sure why some microbes are social. But the cellular slime mold, Dictyostelium discoideum, makes a great model for figuring out why. This organism, a eukaryote, can start out life as a single cell, one that hangs out waiting for a hapless bacterium to wander by so it can have dinner. But if bacteria are in short supply or the soil dries up, slime molds can do some marvelous things. They can start socializing with each other, forming colonies—apparently quite large colonies. But they also can shift from being single-celled organisms or single-celled colonial organisms to becoming a multicellular organism. In the really bad times, these cells can signal to one another to differentiate into two different tissues, officially becoming multicellular.

In addition, these brainless blobs also exhibit altruism, a kind known as suicidal altruism in which some cells in a colony commit cell suicide so that cells elsewhere in the colony can thrive. And as the discovery in the Texas cow pasture shows, the organisms can exist in enormous clonal colonies, a quivering gelatinous mass just under the soil, waiting for conditions to improve.

An affinity for dung

How did the researchers even find this slime mold? They had to get themselves into the “mind” of the slime mold and figure out where this species might be most prone to going clonal, a response to an uninviting environment. Given that slime molds are fond of deep, humid forests, the researchers opted to search for the clonal variety in a dry-ish, open pasture at the edge of such forests. Why would they even expect D. discoideum to be there? Because the amoebae also happen to have an affinity for dung, as well as soil.

After careful sampling from 18 local fields, which involved inserting straws into cow patties and surrounding soil, the research team tested their samples for the presence of amoebae. Once the dishes showed evidence of the slime mold, the investigators then sampled each group and sequenced the genome. That’s when they realized that 40 feet of one cow pasture was one solid mass of amoebae clones.

The winner clones it all?

These findings raise intriguing questions for microbial ecologists. One problem they’re tackling is what determines which clone gets to reproduce so wildly at the edges of acceptable amoeba territory. Is it just one clone that arrives and gets to work, or do several show up, have a competition, and the winner clones all? They tested this idea in the lab and found that none of the clones they tested seemed to have any particular competitive advantage, so the selection process for which amoeba gets to clone at the edges remains a mystery.

Another question that intrigues the ecologists is why these single-celled organisms cooperate with one another in the first place. Such clonal existence is not unknown in nature—aspen trees do it, and so do sea anemones. And researchers have identified as many as 100 genes that seem to be associated with cooperative behavior in the slime mold. One explanation for cooperating even to the extreme of individual suicide is the clonal nature of the colony: the more identical the genes, the more the species derives from sacrificing for other members of the species. They ensure that the same genes survive, just in a different individual.

Machiavellian amoebae: cheaters among the altruists

Not all amoebae are altruistic, and some apparently can be quite Machiavellian. Some individual amoeba carry cooperation genes that have undergone mutations, leading them to be the cheaters among the altruists and take advantage of the altruistic suicide to further their own survival. What remains unclear is why cooperation continues to be the advantageous route, while the mutant cheats keep getting winnowed out.

Amoebae gone to pasture

By Emily Willingham

Word count: 672

 

Lurking beneath the soil and cow patties of a southeast Texas cow pasture, the cellular slime mold cloned itself and cloned itself again until it was about 40 feet across, billions of cells dense. The thing is, this enormous creature was really neither a slime nor a mold, but a group of social microbes, amoebas that were all exactly identical to one another.

No one is quite sure why some microbes are social. But the cellular slime mold, Dictyostelium discoideum, makes a great model for figuring out why. This organism, a eukaryote, can start out life as a single cell, one that hangs out waiting for a hapless bacterium to wander by so it can have dinner. But if bacteria are in short supply or the soil dries up, slime molds can do some marvelous things. They can start socializing with each other, forming colonies—apparently quite large colonies. But they also can shift from being single-celled organisms or single-celled colonial organisms to becoming a multicellular organism. In the really bad times, these cells can signal to one another to differentiate into two different tissues, officially becoming multicellular.

In addition, these brainless blobs also exhibit altruism, a kind known as suicidal altruism in which some cells in a colony commit cell suicide so that cells elsewhere in the colony can thrive. And as the discovery in the Texas cow pasture shows, the organisms can exist in enormous clonal colonies, a quivering gelatinous mass just under the soil, waiting for conditions to improve.

How did the researchers even find this slime mold? They had to get themselves into the “mind” of the slime mold and figure out where this species might be most prone to going clonal, a response to an uninviting environment. Given that slime molds are fond of deep, humid forests, the researchers opted to search for the clonal variety in a dry-ish, open pasture at the edge of such forests. Why would they even expect D. discoideum to be there? Because the amoebae also happen to have an affinity for dung, as well as soil.

After careful sampling from 18 local fields, which involved inserting straws into cow patties and surrounding soil, the research team tested their samples for the presence of amoebae. Once the dishes showed evidence of the slime mold, the investigators then sampled each group and sequenced the genome. That’s when they realized that 40 feet of one cow pasture was one solid mass of amoebae clones.

These findings raise intriguing questions for microbial ecologists. One problem they’re tackling is what determines which clone gets to reproduce so wildly at the edges of acceptable amoeba territory. Is it just one clone that arrives and gets to work, or do several show up, have a competition, and the winner clones all? They tested this idea in the lab and found that none of the clones they tested seemed to have any particular competitive advantage, so the selection process for which amoeba gets to clone at the edges remains a mystery.

Another question that intrigues the ecologists is why these single-celled organisms cooperate with one another in the first place. Such clonal existence is not unknown in nature—aspen trees do it, and so do sea anemones. And researchers have identified as many as 100 genes that seem to be associated with cooperative behavior in the slime mold. One explanation for cooperating even to the extreme of individual suicide is the clonal nature of the colony: the more identical the genes, the more the species derives from sacrificing for other members of the species. They ensure that the same genes survive, just in a different individual.

Not all amoebae are altruistic, and some apparently can be quite Machiavellian. Some individual amoeba carry cooperation genes that have undergone mutations, leading them to be the cheaters among the altruists and take advantage of the altruistic suicide to further their own survival. What remains unclear is why cooperation continues to be the advantageous route, while the mutant cheats keep getting winnowed out.

It’s a blob. It’s an animal. It’s Trichoplax

The irresistibly attractive Trichoplax. Oliver Voigt, courtesy of Wikimedia Commons

Timeline, 2008: One of the greatest quests in animal biology is the search for the “ur-animal,” the proto-creature that lies at the base of the animal family tree. For many years, the sponge held the low spot as most primitive animal, a relatively simple cousin of ours consisting of a few tissues and a tube that filters water for nutrients.

An animal, simple and alone

Research now suggests, however, that there’s an even older cousin at the base of the tree, an animal-like organism with three cell layers and four cell types that moves by undulating and exists alone in its own taxon. This organism, with the species name Trichoplax adhaerens, is the sole living representative of the Placozoa, or “flat animals.” It has been a bit of a mystery creature ever since the amoeba-like things were first noted a century ago in a German aquarium. Today, new techniques in systematics, the study of how living things are related, have helped pinpoint its place on the tree of life. These techniques have, however, left us with a few complex questions about this “simple” animal.

The animal kingdom family tree gets complex fast, with an early division in the trunk. Whatever lies at its base—and we’re still not sure what the organism was—that ancestor yielded two basic animal lineages. One led to sponges (Porifera) and branched to Cnidarians—corals, hydras, and organisms like jellies that have primitive nervous systems. The other lineage is the Bilateria, which includes everything from flatworms to bugs to beluga whales to us. Obviously, this lineage also has developed a nervous system, in many cases one that is quite complex.

Why a sponge will never be nervous

Earlier thinking was that the sponges, in lacking a nervous system, represented some earliest ancestor from which the two lineages sprang. But recent molecular analysis of the sponge and placozoan genomes has left a few systematists scratching their heads. The big headline was that the sea sponge was no longer the most primitive or oldest taxon. That honor may now belong to the placozoan, although some analyses place it as having evolved after Porifera.

An ur-animal? Or just another ur-cousin?

It may go a ways back, but it’s not so far that scientists can say that T. adharens is the “ur-animal,” or “mother of all animals.” In fact, it appears to share a few things in common with Bilateria, such as special protein junctions for holding tissues together, but computer analysis places it squarely in the Cnidaria branch of the animal family tree. Thus, this “weird, wee beastie,” while possibly older than the sponge, is still not the proto-ancestral animal condition. Rather than being the “ur-animal” from which all other animals sprang, it’s more like an “ur-cousin” of Bilateria.

Nervous system genes but no nervous system?

T. adhaerens also represents another conundrum for evolutionary biologists and systematists. It and the sponge both carry coding in their genomes for neural proteins, yet neither have nervous systems. The Cnidarian nervous system itself may have evolved parallel to that of the Bilateria, an evolutionary phenomenon known as “convergent evolution.” When evolutionary processes occur in parallel, unrelated species may share adaptations—such as a nervous system—because of similar selection pressures. The results are what we call “analogous structures,” which have similar functions and may even seem quite similar. But they are shared because of similar evolutionary pressures, not because of a common ancestry.

Lost traits make evolutionary biologists tear out their hair

The primitive placozoan does not have a nervous system, although organisms that arose later in the Cnidarian lineage, such as jellies, do. Yet those neural genes in its genome leave an open question and a continuing debate: Is the placozoan an example of another common evolutionary phenomenon in which a trait arises, but then is lost? Some scientists have suggested that there may have been an even older version of a nervous system, predating the Cnidarian/Bilateria split. This trait then vanished, leaving behind only these traces in the primitive placozoan and sponge genomes. With this scenario, the two nervous systems would have a shared ancestry: instead of being analogous traits resulting from convergent evolution, they would represent homologous traits, shared because of a common neural ancestry.

Your mother *is* always with you

Mother and child, microchimeras

When you’re in utero, you’re protected from the outside world, connected to it only via the placenta, which is supposed to keep you and your mother separated. Separation is generally a good thing because you are foreign to your mother, and she is foreign to you. In spite of the generally good defenses, however, a little bit of you and a little bit of her cross the barrier. Scientists have recently found that when that happens, you often end up toting a bit of mom around for decades, maybe for life.

The presence of cells from someone else in another individual is called microchimerism. A chimera in mythology was a beast consisting of the parts of many animals, including lion, goat, and snake. In genetics, a chimera carries the genes of some other individual along with its own, perhaps even the genes of another species. In microchimerism, we carry a few cells from someone else around with us. Most women who have been pregnant have not only their own cells but some cells from their offspring, as well. I’m probably carrying around cells from each of my children.

Risks and benefits of sharing

Microchimerism can be useful but also carries risks. Researchers have identified maternal cells in the hearts of infants who died from infantile lupus and determined that the babies had died from heart block, partially from these maternal cells that had differentiated into excess heart muscle. On the other hand, in children with type 1 diabetes, maternal cells found in the pancreatic islets appear to be responding to damage and working to fix it.

The same good/bad outcomes exist for mothers who carry cells from their children. There has long been an association between past pregnancy and a reduced risk of breast cancer, but why has been unclear. Researchers studying microchimerism in women who had been pregnant found that those without breast cancer had fetal microchimerism at a rate three times that of women who with the cancer.

Microchimerism and autoimmunity

Autoimmune diseases develop when the body attacks itself, and several researchers have turned to microchimerism as one mechanism for this process. One fact that led them to investigate fetal microchimerism is the heavily female bias in autoimmune illness, suggesting a female-based event, like pregnancy. On the one hand, pregnancy appears to reduce the effects of rheumatoid arthritis, an autoimmune disorder affecting the joints and connective tissues. On the other hand, women who have been pregnant are more likely to develop an autoimmune disorder of the skin and organs called scleroderma (“hard skin”) that involves excess collagen deposition. There is also a suspected association between microchimerism and pre-eclampsia, a condition in pregnancy that can lead to dangerously high blood pressure and other complications that threaten the lives of mother and baby.

Human leukocyte antigen (HLA)

The autoimmune response may be based on a similarity between mother and child of HLA, immune-related proteins encoded on chromosome 6. This similarity may play a role in the immune imbalances that lead to autoimmune diseases; possibly because the HLAs of the mother and child are so similar, the body clicks out of balance with a possible HLA excess. If they were more different, the mother’s immune system might simply attack and destroy fetal HLAs, but with the strong similarity, fetal HLAs may be like an unexpected guest that behaves like one of the family.

Understanding the links between microchimerism and disease is the initial step in exploiting that knowledge for therapies or preventative approaches. Researchers have already used this information to predict the development of a complication in stem cell transplant called “graft-versus-host disease” (GVH). In stem cell transplants, female donors with previous pregnancies are more associated with development of GVH because they are microchimeric. Researchers have exploited this fact to try to predict whether or not there will be an early rejection of a transplant in kidney and pancreas organ transplants.

(Photo courtesy of Wikimedia Commons and photographer Ferdinand Reus).

An author reading today

Doing my author reading at the library today with my friend Charles Darwin on the screen

Today, I did my first reading/teaching presentation from The Complete Idiot’s Guide to College Biology. Below are a couple of excerpts from what I read today.

From Chapter 16: Darwin, Natural Selection, and Evolution

Evolution, a change in a population over time, can be a controversial concept, and things were no different when Darwin first proposed his theory of how evolution happens. Since that time, we’ve identified several other ways by which evolution can occur. Scientists have synthesized natural selection and genetics and worked out a way to identify if evolution is happening in a population.

The Historical Context of Darwin’s Ideas

Charles Darwin was born on February 12, 1809, into a society with fixed ideas about the role of divinity–specifically the Christian God–in nature. Darwin’s destiny, as it turned out, was to address nature’s role in nature, rather than God’s. He was not completely comfortable in some respects with that destiny, but this man was born with his ear to the ground, listening to Nature’s heartbeat. He was born to bring to us a greater understanding of how nature fashions living things.

Yet, he did not emerge into a howling wilderness of antiscientific resistance. Scientists and philosophers who had come before him had posited bits and pieces of what would become Darwin’s own theory of how evolution happens. But it required Charles Darwin to synthesize those bits and pieces–some of them his own, gathered on the significant voyage of his lifetime–to bring us a complete idea of how nature shapes new species from existing life.

Alfred Russel Wallace: The Unknown Darwin

Alfred Russel Wallace developed the theory of evolution by natural selection at the same time as Darwin. His road to enlightenment came via his observations on another island chain, the Malay Archipelago. Like Darwin, Wallace was a naturalist savant, and on this archipelago alone, he managed to collect and describe tens of thousands of beetle specimens. He, too, had read Malthus and under that influence had begun to formulate ideas very similar to Darwin’s. The British scientific community of the nineteenth century was a relatively small world, and Wallace and Darwin knew one another. In fact, they knew each other well enough to co-present their ideas about natural selection and evolution in 1858.

Nevertheless, Wallace did not achieve Darwin’s profile in the field of evolution and thus today does not have his name inscribed inside a fish-shaped car decal. The primary reason is likely that Darwin literally wrote the book on the theory of evolution by means of natural selection. Wallace, on the other hand, published a best seller on the Malay Archipelago.

From Chapter 13: DNA

DNA, as the central molecule of heredity, is key to many aspects of our lives (besides, obviously, encoding our genes). Medicines and therapies are based on it. TV shows and movies practically feature it as a main character. We profile it from before we’re born until after we die, using it to figure out what’s wrong, what’s right, what’s what when it comes to who we are, and what makes us different and the same.

But it wasn’t so long ago that we weren’t even sure that DNA was the molecule of heredity, and it was even more recently that we finally started unlocking the secrets of how its genetic material is copied for passing along to offspring.

The History and Romance of DNA

The modern-day DNA story is dynamic and fascinating. But it can’t compare to the tale of the trials, tribulations, and downright open hostilities that accompanied our recognition of its significance.

Griffith and His Mice

Our understanding started with mice. In the 1920s, a British medical officer named Frederick Griffith performed a series of important experiments. His goal was to figure out the active factor in a strain of bacteria that could give mice pneumonia and kill them.

His bacteria of choice were Streptococcus pneumoniae, available in two strains. One strain infects and kills mice and thus is pathogenic, or disease causing. These bacteria also have a protein capsule enclosing each cell, leading to their designation as the Smooth, or S, strain. The other strain is the R, or rough, strain because it lacks a capsule. The R strain also is not deadly.

Wondering whether or not the S strain’s killer abilities would survive the death of the bacteria themselves, he first heat-killed the S strain bacteria. (Temperature changes can cause molecules to unravel and become nonfunctional, “killing” them.) He then injected his mice with the dead germs. The mice stayed perky and alive. Griffith mixed the dead, heat-killed S strain bacteria with the living, R-strain bacteria and injected the mice again. Those ill-fated animals died. Griffith found living S strain cells in these rodents that had never been injected with live S strain bacteria.

With dead mice all around him, Griffith had discovered that something in the pathogenic S strain had survived the heat death. The living R strain bacteria had picked up that something, leading to their transformation into the deadly, pathogenic S strain in the mice. It was 1928, and the question that emerged from his findings was, What is the transforming molecule? What, in other words, is the molecule of heredity?

Hershey and Chase: Hot Viruses

A fiery debate tore through the ranks of molecular biologists and geneticists in the early twentieth century, arguing about whether proteins or DNA were the molecules of heredity. The protein folk had a point. With 20 possible amino acids, proteins offer far more different possible combinations and resulting molecules than do the four letters (nucleotide building blocks) of the DNA alphabet. Protein advocates argued that the molecule with the most building blocks was likely responsible for life’s diversity.

In a way, they were right. Proteins underlie our variation. But they were also fundamentally wrong. Proteins differ because of differences in the molecule that holds the code for building them. And that molecule is DNA.

Like what you’ve read? Read the rest in The Complete Idiot’s Guide to College Biology.

Genetic analysis: my results and my reality

A few months ago, it was National DNA Day or something like that, and one of the genetics analysis companies had a sale on their analysis kits, offering a full panel of testing for only $100. Giddy with the excitement of saving almost $1000 on something I’d long been interested in doing, I signed on, ordering one kit each for my husband (a.k.a. “The Viking”) and me. Soon, we found ourselves spending a romantic evening spitting into vials and arguing about whether or not we’d shaken them long enough before packaging them.

The company promised results in six weeks, but they came much faster than that, in about three weeks. Much to my relief, I learned that neither of us carries markers for cystic fibrosis and that I lack either of the two main mutations related to breast cancer. Those basic findings out of the way, things then got more complex and more interesting.

How it works

First, a bit of background. These tests involve sequencing of specific regions to look for very small changes, a single nucleotide, in the DNA. If there is a study that has linked a specific mutation to a change in the average risk for a specific disorder or trait, then the company notes that. The more data there are supporting that link, the stronger the company indicates the finding is. Thus, four gold stars in their nomenclature means, “This is pretty well supported,” while three or fewer slate stars means, “There are some data for this but not a lot,” or “The findings so far are inconsistent.”

Vikings and Ireland

The Viking is a private person, so I can’t elaborate on his findings here except to say that (a) he is extraordinarily healthy in general and (b) what we thought was a German Y chromosome seems instead to be strictly Irish and associated with some Irish king known as Niall of the Nine Hostages. Why hostages and why nine, I do not know. But it did sort of rearrange our entire perception of his Y chromosome and those of our three sons to find this out. For the record, it matches exactly what we learned from participating in the National Geographic Genographic project. I’d ask the Viking if he were feeling a wee bit o’ the leprachaun, but given his somewhat daunting height and still Viking-ish overall demeanor (that would be thanks to his Scandinavian mother), I’m thinking he doesn’t. Lord of the Dance, he is not.

Markers that indicate an increased risk for me

I have an increased risk of…duh

Looking at the chart to the left (it’s clickable), you can see where I earned myself quite a few four gold stars, but the ones that seem most relevant are those with a 2x or greater increased risk: lupus, celiac disease, and glaucoma. The first two do not surprise me, given my family’s history of autoimmune disorders.

If you focus on a list like this too long, you can start to get a serious case of hypochondria, worrying that you’re gonna get all of these things thanks to those glaring golden stars. But to put it into context, for the lupus–for which my risk is 2.68 times higher than a regular gal’s–that still leaves me in the population in which 0.66 persons out of every 100 will develop this disorder. Compare that to the 0.25 out of every 100 in the regular-gal population, and it doesn’t strike me as that daunting.

Some of those other things on there? Well, let’s just say they’re close. My risk of thyroid cancer might be raised…but I no longer have a thyroid. Hypertension risk is increased–and I have stage 2 hypertension. Gallstones, gout, alcholism, asthma…based on family history, it’s no surprise to me to see some mixed or clear risk involved with these, although I have none of them. Does that mean that someone else with these increased risks will have related real-life findings? No. It only means that you’re at a bit more risk. It’s like riding a motorcycle vs. driving a car. The former carries more risk of a fatal wreck, but that doesn’t mean you’re absolutely gonna die on it if you ride it.

Disorders for which my risk is allegedly decreased

I have a decreased risk of...

None of my decreased risk findings are very eye catching in terms of actual drop in risk except for Type II diabetes (now where is my bag of sugar?). As I have been under evaluation for multiple sclerosis and have a family member with it, it’s interesting to see that my risk for it, based on existing studies and known polymorphisms, is decreased. And even though I know that much of this is largely speculative and based on little firm data, it’s still sort of comforting to see “decreased risk” and things like “melanoma” in the same group.

Don’t make my brown eyes blue!

And they didn’t. They nailed the eye color and other trait-related analysis, such as level of curl to the hair, earwax type, alcohol flush reaction, lactose intolerance (unlikely), and muscle performance (I am not nor have I ever been a sprinter). And even though I do not have red hair, they reported that I had a good chance of it, also true given family history. I am not resistant to malaria but allegedly resistant to norovirus. I wish someone had informed my genes of that in 2003 when I was stricken with a horrible case of it.

Ancestral homeland

Yep. They nailed this one. One hundred percent European mutt. Mitochondria similar to…Jesse James…part of a haplogroup that originated in the Near East about 45,000 years ago then traveled to Ethiopia and Egypt and from there, presumably, into Europe. It’s a pretty well traveled haplotype and happens to match exactly with the one identified by the National Geographic Genographic project. When it comes to haplotypes, we’re batting 1000.

In summary

Some of these findings are reliable, such as the absence of the standard breast cancer mutations or the presence of certain mutations related to autoimmune disorders, while other findings are iffy. The company duly notes their iffiness  in the reports, along with the associated citations, polymorphisms, and level of risk identified in each study. They don’t promise to tell you that your ancestors lived in a castle 400 years ago or hailed from Ghana. From this company, at any rate, the results are precise and precisely documented, and as I noted, pretty damned accurate. And they’re careful to be a clear as possible about what “increased risk” or “decreased risk” really means.

It’s fascinating to me that a little bit of my spit can be so informative, even down to my eye color, hair curl, and tendency to hypertension, and I’ve noted that just in the days since we received our results, they’ve continually updated as new data have come in. Would I be so excited had I paid $1100 for this instead of $200? As with any consideration of the changes in risk these analyses identified, that answer would require context. Am I a millionaire? Or just a poor science writer? Perhaps my genes will tell.

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