Genetic perks

Genetic super powers

Certain genes can boost your sporting prowess and overall health, giving you a leg-up in life. Are you one of the lucky ones?

WORDS REBECCA DOUGLAS

Some fortunate individuals only need five hours of sleep a night. Unlike many of us burning the candle at both ends and relying on coffee to perk us up, they are happy and well-rested on this minimal amount of shut-eye.

It turns out, this is a handy condition caused by rare mutations in genes called ADRB1 and DEC2.

“There are some people who genetically require less sleep and get by perfectly well on four to six hours of sleep,” ResMed sleep expert Carmel Harrington says. “They don’t need to take naps or sleep in on weekends to recover from lack of sleep. These individuals are different from those who choose to limit their sleep.”

There is also a long sleep gene, which causes individuals to sleep 10-12 hours a night rather than the usual eight.

While other lifestyle factors come into play when it comes to the amount of rest we require, how much slumber our body needs is largely influenced by the genetic lottery.

“The prevalence of these genes is not well defined but is estimated to be less than 1 per cent of people are genetically short sleepers and less than 1 per cent are genetically long sleepers,” Dr Harrington says.

Power-ups

Other genetic tweaks may result in better bone strength (LRP5), super muscle strength (myostatinrelated muscle hypertrophy), superior speed (ACTN3) and super resistance to developing high cholesterol (PCSK9).

When it comes to our ability to run, some of us are built for speed and others are better equipped for long distances. The one we’re better at depends on whether we have more fast-twitch muscle fibres (which enable speed and power) or slow-twitch muscle fibres (to help with endurance), aided by our genetics.

In the case of the ACTN3 gene, most of us are built to run fast, but many of us are genetically ill-equipped to win a sprint race, according to Murdoch Children’s Research Institute senior research officer Peter Houweling.

“In around 20 per cent of people, or about 1.5 billion people worldwide, they have a mutation or defect which means that they don’t express ACTN3 in their fast muscle fibres,” Dr Houweling says. “If you’re ACTN3 deficient, you’re basically not going to be an elite Olympic sprinter.”

While these people may lose out in a foot race, the good news is they’re more likely to excel in an endurance event.

Built strong

When it comes to muscle strength, myostatin helps regulate the size of your muscles, The University of Melbourne’s Centre for Muscle Research director Gordon Lynch says.

“Myostatin levels keep the muscle size in check,” Prof Lynch says. “If myostatin levels are high, that generally reduces the muscle mass, whereas if myostatin levels are very low, then muscle mass is generally larger.”

Those born with unusually low amounts of myostatin will grow big muscles much more readily than those with standard myostatin levels.

Similarly, individuals with a mutation in the LRP5 gene can have bones that are almost unbreakable. “People with such a genetic variation basically never have broken bones, because they have incredible bone strength,” Prof Lynch says.

When it comes to our ability to run, some of us are built for speed and others are better equipped for long distances.

GENETIC SUPER POWERS CAN BE USED IN WORK, REST AND PLAY

Trade-offs

There can be downsides to some of these genetic super powers; the rest of the body is not equipped to handle the superior strength in one particular area, such as the muscles.

“Muscles contract, they pull on tendons, and the tendons move bones to allow us to move,” Prof Lynch says. “You could be more susceptible to certain types of injury if the muscle produces forces that exceed what the tendon can handle.”

Usually, exercise prevents this type of mismatch in the body by building up surrounding areas along with muscles and bone. For non-genetically gifted human beings without super strength in these areas, what we get out of our athletic pursuits and life in general comes down to how much work we do to improve ourselves. In the end, that might not be a bad way to go.