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New Possible SIDS Genes Identified
ScienceDaily is reporting that researchers at the Mayo Clinic have identified two more cardiac genes that could contribute to sudden infant death syndrome (SIDS). From the article: "In the two recent separate studies, researchers examined caveolin-3 (CAV3) and the cardiac ryanodine receptor (RyR2) and found molecular and functional evidence in both to implicate them as SIDS-susceptibility genes. Researchers examined the tissue of 135 unrelated cases of SIDS -- in infants with an average age of 3 months old -- that had been referred to Mayo Clinic's Sudden Death Genomics Laboratory for molecular autopsy. In each study, two of the 135 cases possessed mutations in either CAV3 or RyR2."
Unless it has major advantages in youth/adult life. It increases the chance of death long before sexual maturity, evolution usually weeds those genes out rather quickly. Does the gene have any other known effect?
I still have more fans than freaks. WTF is wrong with you people?
Something that occurs in less than 2% of studied cases is a "potential contributing cause"?
Have they tried researching culling songs yet?
Aero
Please stop hurting America -- Jon Stewart
In each study, two of the 135 cases possessed mutations in either CAV3 or RyR2.
So one case of each mutation was found in each trial, and 266 of the 270 cases remain unsolved. It sounds like it is barely above a statistical anomaly.
If you take a random sample of 270 people that like fishing, there will be some mutation that is common between two or more of them, but that's hardly enough to claim that this mutation makes you enjoy fishing.
It looks like there is still a lot more research to do before we understand what the effects of different genes / mutations are.
I'll probably be modded down for this...
Seems like a cool organisation. Wikipedia:
"Mayo Clinic is significant in the way the medical physicians' are paid. In most health care systems, medical doctors are paid based on the number of patients that they see. The more patients seen, the more a doctor gets paid. At Mayo Clinic, medical doctors are paid a salary that is unaffected by patient volume. This allows the doctors to spend time with their patients and not worry so much about time constraints. Physicians and surgeons have no undue influence upon them to do more procedures and operations."
That's a marvellous philosophy if you ask me, and they still made US$5.6 billion in 2004. Good for them.
Recessive genes survive because you can carry the gene and suffer no side-effects. You will pass it on to half of your children (on average), who will like you, become carriers but show no symptoms. If each carrier has an average 2 children, you can expect that the number of carriers will stay roughly constant from one generation to the next.
For a child to show symptoms, both of their parents must be carriers of the recessive gene, and even then there is only a one-in-four chance of a child receiving two copies of the gene in question.
Fatal genetic diseases can survive in the gene pool indefinitely if the gene that causes it is recessive.
I'll probably be modded down for this...
From what I understand, SIDS is caused when the brain doesn't properly send the "I'm not getting enough oxygen" message or the baby's unable to do anything about the message being sent. For example, sleeping on the front with fluffy blankets can make it hard for them to move around, even if they get the appropriate signal. In other cases, it may be that the signal itself may not get sent, as that part of the brain isn't developed enough. Things like pacifiers seem to help, perhaps because it maintains a level of awakeness or simply keeps their mouth open.
It may be that the search for a root genetic cause may be futile. The good news is that simple physical precautions such as sleeping on the back and pacifiers seem to cut down on SIDS dramatically.
Even if genetics play a role, it may be different than people think. It's important to realize that evolution often shoots for the "good enough" solution and that we carry around the baggage of billions of years of effort. Perhaps the babies that survived best historically were those who spent their limited growth "energy" on developing skeletal and muscle tissue. The part of the brain that signals low oxygen wasn't very useful during the first few months, as children typically slept in the arms of an adult. Speculation, of course, but it hopefully shows the ways that evolutionary pressures can lead to odd results.