An Athletic Teen Suddenly Prone to Falls and Fractures

Inas H. Thomas, MD


June 06, 2022

Physical Examination and Workup

His weight is 109 lb 9.1 oz (49.7 kg), which places him in the 34th percentile based on the Centers for Disease Control and Prevention (CDC) weight-for-age data. His height is 5 ft 3.7 in (1.618 m), which places him in the 26th percentile, based on CDC data. His body mass index (BMI) is 18.98 kg/m2, which places him in the 42nd percentile, based on CDC data.

He is a thin, average-height male with an unremarkable examination. His sclera is white. His dentition is normal without caries. He is in Tanner stage 3 for puberty. No scoliosis is present. His extremities are thin but with appropriate muscle tone. He has no bowing and no birthmarks.

His laboratory results are as follows:

  • Intact parathyroid hormone (PTH) level: 65 pg/mL (reference range, 10-65 pg/mL)

  • Calcium PTH level: 7 mg/dL (reference range, 8.6-10.3 mg/dL)

  • Phosphorus level: 3 mg/dL (reference range, 2.7-4.6 mg/dL)

  • Alkaline phosphatase level: 370 IU/L (reference range, 90-420 IU/L)

  • Thyroid-stimulating hormone (TSH) level: 2.43 mIU/L (reference range, 0.3-5.5 mIU/L)

  • 25-hydroxy vitamin D level: 20 ng/mL (reference range, 25-100 ng/mL)

Dual-energy x-ray absorptiometry (DEXA) scanning (Hologic Discovery A) reveals a left femoral neck Z-score of -0.8, a left hip Z-score of -1, and a lumbar spine Z-score of -1.8.


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