Ah, collagen. The most abundant protein in animals. Great for cooking into rich sauces – and glue (hence the name). It gives structure to mammals’ extracellular space. Your skin, tendons, ligaments, blood vessels, mucous membranes, cartilage, bones, and teeth all depend on collagen for strength. When our collagen lets us down, we can expect trouble.

Several diseases, from rheumatoid arthritis to scurvy, are connective-tissue diseases. Several attack our abundant collagen specifically. Sometimes, though, collagen weakens not because it’s under attack, but because it never formed right to begin with. Several genes have been identified as causing Ehlers-Danlos Syndrome (EDS), congenitally weakened cartilage, and several genes remain to be discovered. The worst types of EDS are super-weird, and super-scary. Your silly-putty skin could be so loose and stretchy that it’s obvious from birth you’d be a freak-show star, pulling your neck skin over your face for strangers’ amusement. Or maybe your joints dislocate so easily you’d join the circus as a contortionist, disarticulating yourself for cold, hard cash. Or maybe EDS causes your organs to explode, far less marketable but still super-scary. Many of us, if we’ve heard of EDS at all, have more reason to think “circus freak” than “subtle.”