Diagnosis of Delayed Growth and Puberty in a 12-Year-Old

Key Clinical Findings

• The patient is 12 years old with delayed puberty and delayed bone age.
• Growth was normal until age 1 year.
• Subsequently, height and weight fell below the 3rd centile.
• Crucially, the child maintained a normal height velocity despite being below the 3rd centile.

Analysis of Options

• Familial short stature typically involves genetic factors and may have normal or slightly delayed bone age, but doesn't perfectly fit the drop after infancy combined with normal velocity.
• Constitutional growth delay (CGD) is characterized by delayed bone age, delayed puberty, and normal growth velocity relative to bone age. This pattern often presents as a drop in percentile after infancy, but the growth rate is appropriate for the delayed skeletal maturation. This aligns with the patient's presentation, especially the normal height velocity.
• Growth hormone deficiency (GHD) would typically present with significantly reduced height velocity, which contradicts the information provided.
• Skeletal dysplasia usually involves disproportionate short stature and specific bone abnormalities, which are not mentioned in the case description.

Conclusion

The combination of delayed puberty, delayed bone age, and a persistently normal height velocity in a child whose growth fell after the first year strongly suggests Constitutional growth delay. This condition represents a normal variant of growth where puberty and skeletal maturation occur later than average, but ultimately follow a normal trajectory.