Which of the following is most likely to be associated with delayed bone age?

• A. Osteogenesis imperfecta
• B. Diabetes mellitus type 1
• C. Marfan syndrome
• D. Hypothyroidism

Answer: (D)

Delayed bone age means the skeleton is maturing more slowly than the child's actual age. Thyroid hormone is essential for normal growth and timely skeletal maturation; when there is hypothyroidism, growth plate activity slows and epiphyseal maturation is delayed, so radiographs show a bone age younger than the chronological age. This makes hypothyroidism the condition most commonly associated with delayed bone age. Other conditions listed—osteogenesis imperfecta, diabetes mellitus type 1, and Marfan syndrome—do not characteristically cause a delayed bone age; they affect bone health, growth patterns, or stature in different ways, but bone age is not typically delayed in them.