Single most likely diagnosis
- C. amino acid transport abnormality: The presence of hexagonal crystals in the urinalysis and a positive urinary cyanide nitroprusside test are indicative of cystinuria, a condition caused by an amino acid transport abnormality. Cystinuria is characterized by the formation of cystine stones, which are often hexagonal in shape. The family history of similar problems also supports a genetic condition like cystinuria.
Other Likely diagnoses
- A. excessive intestinal reabsorption of oxalate: This condition can lead to hyperoxaluria, a cause of kidney stones. However, the specific findings of hexagonal crystals and a positive cyanide nitroprusside test are more suggestive of cystinuria.
- B. abnormality of uric acid metabolism: This can cause uric acid stones, but the description provided does not specifically point towards uric acid stones.
Do Not Miss
- D. parathyroid adenoma: Although less likely given the specific findings, a parathyroid adenoma can cause hyperparathyroidism, leading to hypercalcemia and potentially kidney stones. Missing this diagnosis could have significant implications due to the potential for severe hypercalcemia and its effects on various bodily systems.
Rare diagnoses
- Other rare genetic disorders affecting kidney stone formation, such as primary hyperoxaluria or Dent's disease, could be considered but are less likely given the specific clues pointing towards cystinuria.