In the book series "Odd Thomas", Danny Jessup has what genetic disease?

The story behind the answer

In Dean Koontz’s Odd Thomas series, Danny Jessup, Odd’s close friend, suffers from osteogenesis imperfecta, a genetic collagen disorder that makes bones extraordinarily fragile. His frequent fractures and reliance on a wheelchair reflect this “brittle bone” condition, grounding the supernatural story in very human vulnerability.

Osteogenesis imperfecta results from defects in type I collagen (often COL1A1/COL1A2), leading to weak bones, blue sclerae, and sometimes hearing loss. Memory aid: osteo = bone, genesis imperfecta = imperfect formation—think “glass-bones Danny.” By contrast, cystic fibrosis involves thick lung mucus and pancreatic issues, adrenoleukodystrophy damages myelin and adrenal function, and spinocerebellar ataxia primarily causes coordination problems. Knowing these distinctions makes Danny’s diagnosis unmistakable.