An infant born with a genetic defect that causes little or no brown fat to be formed will have

A. difficulty absorbing nutrients from the intestine
This is related to gastrointestinal function, not brown fat. Brown fat is involved in thermoregulation, not nutrient absorption.

B. difficulty regulating his body temperature
Brown fat is specialized for non-shivering thermogenesis, particularly in newborns. Without it, the infant would struggle to generate body heat and maintain a stable temperature.

C. very stretchy tendons and skin
This suggests a connective tissue disorder like Ehlers-Danlos syndrome, not a defect in brown fat.

D. a reduced bone mass
Brown fat does not directly influence bone development or bone mass.

E. difficulty breathing
Respiratory function may be affected in other conditions, but brown fat deficiency does not directly impair breathing mechanics.

A. osteogenesis imperfecta
This is brittle bone disease, caused by defective collagen, not muscle turning into bone.

B. osteopetrosis
This is a rare condition involving overly dense bones due to osteoclast failure, not soft tissue ossification.

C. chondroidal ossification
This is not a recognized clinical condition. Ossification of cartilage does occur in development but doesn’t describe Harry's case.

D. fibrodysplasia ossificans progressiva (FOP)
FOP is a rare genetic disorder where soft connective tissues such as muscles, tendons, and ligaments turn into bone, progressively restricting movement and ultimately leading to complications that may be fatal.

E. osteoarthritis
This involves cartilage degeneration at joints due to wear and tear-not ectopic bone formation in soft tissues.