Constitutional Delay of Growth and Puberty
A 13-year-old girl has not started breast development. Her height and weight are below the 5th percentile and have tracked along that percentile since age 4. She has Tanner stage 1 breasts and pubic hair, no dysmorphic features or webbed neck, and a normal sense of smell. Bone age is delayed by 2 years and thyroid function is normal. Which is the most likely cause of her delayed puberty?
- A.Constitutional delay of growth and pubertyCorrect
- B.Turner syndrome with gonadal dysgenesis
- C.Congenital hypogonadotropic hypogonadism
- D.Acquired primary hypothyroidism
Explanation
Constitutional delay of growth and puberty is by far the commonest explanation for both short stature and absent pubertal development in an otherwise healthy adolescent, and it is essentially a self-resolving variant of normal timing rather than a disease. The hallmark is a child whose height tracks along a low but steady percentile, whose bone age is delayed by roughly 2 years, and whose height prediction based on that delayed bone age is appropriate for the mid-parental target, meaning eventual adult height is normal. A supportive family history of a late-maturing parent is common and useful, but its absence does not exclude the diagnosis, since recall is unreliable and the trait is not always reported. Turner syndrome must be considered in any girl with short stature and delayed puberty and is diagnosed by karyotype, but it is typically accompanied by a growth curve that falls progressively away from the percentiles and often by webbed neck, cubitus valgus, low hairline, or cardiac and renal anomalies. Congenital hypogonadotropic hypogonadism, including Kallmann syndrome, presents with absent puberty and low gonadotropins, frequently with anosmia and a normal or tall stature rather than proportionate shortness with delayed bone age. Acquired primary hypothyroidism causes growth deceleration with weight gain and delayed bone age, but thyroid function here is normal. Management of constitutional delay is reassurance with monitoring, and a short course of low-dose sex steroid may be offered when psychosocial distress is significant.
Why each option
- A.
- Correct. Steady low-percentile growth, delayed bone age, and normal screening studies define constitutional delay, and a negative family history does not exclude it.
- B.
- Turner syndrome usually shows progressive growth failure with dysmorphic or cardiac and renal features and requires a karyotype to confirm.
- C.
- Congenital hypogonadotropic hypogonadism typically features anosmia and normal or tall stature rather than proportionate short stature with delayed bone age.
- D.
- Primary hypothyroidism causes growth arrest with weight gain, but thyroid function tests are normal in this girl.
Reference: Nelson Textbook of Pediatrics, 22nd ed., 2024; UpToDate 2025, Approach to the patient with delayed puberty
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