Want to Climb Kilimanjaro? Gene Tests Predict Altitude Sickness
On hisِ 27th birthday, David Hillebrandt andِ his wife Sally began toِ climb Mount Kenya, theِ second-highest mountain inِ Africa afterِ Kilimanjaro.
Instead ofِ gearing upِ andِ heading straight forِ the mountain’s tallest peak—which reaches 5,199 meters—the couple started theirِ journey moreِ leisurely, trekking throughِ scenic ridges andِ valleys aroundِ the mountain atِ anِ altitude ofِ aboutِ 3,000 meters.
David, whoِ today serves asِ a medical advisor toِ theِ British Mountaineering Council, alreadyِ had considerable climbing experience atِ the time: heِ hadِ scaled a 5,790-meter peak inِ Pakistan andِ 3,960-meter peaks inِ the European Alps.
But Sally wasn’t the one who needed to stop and turn around.
He knew fromِ previous climbs thatِ heِ was prone toِ altitude sickness, butِ he thought circling theِ mountain atِ 3,000 meters wouldِ beِ a good wayِ toِ acclimatize.
Scientists haveِ known forِ a whileِ thatِ someِ people areِ inherently moreِ susceptible toِ altitude sickness thanِ others—and thatِ this susceptibility isِ heritable—but onlyِ nowِ areِ they onِ the trail ofِ the culprit genes.
Such a precise genetic test wouldِ greatly benefit theِ military, whichِ currentlyِ has noِ way ofِ predicting whichِ soldiers willِ fall ill whenِ flown toِ high altitudes andِ would ratherِ notِ waste money onِ expensive acclimatization drugs.
Written in blood
The pursuit ofِ a genetic test forِ altitude sickness began inِ earnest a fewِ years agoِ in Robert Roach’s laboratory atِ the University ofِ Colorado.
In 2010, 28 people inِ Roach’s lab ascended toِ anِ altitude ofِ 4,875 meters withoutِ everِ leaving theِ ground.
Roach purposefully recruited a mixture ofِ people whoِ wereِ susceptible toِ altitude sickness andِ people whoِ hadِ never hadِ problems inِ high climes.
Altitude sickness isِ alsoِ the scourge ofِ entirelyِ differentِ population ofِ mountain-dwellers: cows.
West—when ranchers takeِ cattle toِ graze onِ grassy mountain slopes—tens ofِ thousands ofِ cows die becauseِ they cannotِ adapt toِ theِ thin, oxygen-poor air.
Healthy cows respond toِ low-oxygen environments inِ a characteristic way: theirِ hearts beat faster toِ deliver enoughِ oxygenated blood toِ theِ body andِ brain, andِ blood vessels inِ the lung constrict toِ shunt blood toِ theِ organ’s oxygen-rich areas.