X-Linked Hypophosphataemia – Board-Style Questions

What this deck covers

X-linked hypophosphataemia in 18 board-style clinical cases with worked explanations. Each case gives you a clinical vignette, four options, the correct answer, and an explanation of why each of the other three is wrong, with the guideline or textbook it follows named on the answer.

Board-style teaching questions for paediatricians and trainees preparing for paediatric board, MRCPCH and licensing examinations. Written from published guidelines and standard paediatric textbooks, with the source named on every answer.

The 18 cases, in order

1. Proving the leak
2. The wrong range
3. Passing it on
4. Six months on
5. A targeted treatment
6. The older way
7. A scan of the kidneys
8. A rising PTH
9. Getting the level right
10. Switching treatments
11. A sore gum
12. The shape of the head
13. Still short
14. Straightening the legs
15. Stiff joints in an adult
16. A new baby
17. Treatment in adult life
18. A new low phosphate

Diagnoses and management options tested

Across the 18 cases you are asked to choose between options such as: A normal urine calcium to creatinine ratio, Compare it with age-specific ranges, Half of his sons and half of his daughters, He has not been taking the prescribed vitamin D at home at all, Growth hormone injections given every night, Phosphate several times a day with calcitriol, Kidney stones from a urine infection, Primary hyperparathyroidism from a single parathyroid adenoma, A fasting phosphate in the low-normal range, Continue both medicines alongside the burosumab, Poor oral hygiene, with plaque building up on the teeth, Migraine with aura, which is common at this age, Short stature with short legs, common despite treatment, A higher dose of burosumab to straighten the bowing.

Clinical pearls from this deck

• Low phosphate and a low TmP/GFR: the kidneys are wasting it.
• A ‘normal’ phosphate in a toddler may be low for her age.
• Affected father: every daughter, no son.
• Rickets that ignores vitamin D: think phosphate wasting.
• Block FGF23 to treat the cause: burosumab.
• Conventional treatment: frequent phosphate with active vitamin D.

Work through the deck once for recognition, then again a week later to test yourself — each question gives the answer and explains why every other option fails.

More from this system: all Endocrinology Board Questions case decks · pediatric reference values.