Adult hypophosphatasia and a low level of red blood cell thiamine pyrophosphate.

OBJECTIVE

To report the first adult case of hypophosphatasia and absence of intestinal alkaline phosphatase (ALP) isoenzymes associated with a low level of red blood cell thiamine pyrophosphate.

METHODS

We describe the clinical manifestation and laboratory findings in our patient and discuss underlying factors that potentially contribute to her condition.

RESULTS

A 33-year-old Vietnamese-American female was referred for a long history of low levels of serum ALP and absence of intestinal ALP isoenzyme. She had a normal level of urinary phosphoethanolamine and a high level of plasma pyridoxal-5p-phosphate. She was found to have a low level of red blood cell thiamine pyrophosphate.

CONCLUSION

Our adult case of hypophosphatasia presented with an absence of intestinal ALP isoenzyme that might result in decreasing the absorption of thiamine in the intestinal tract. Therefore, the thiamine level should be considered in hypophosphatasia with absence of intestinal ALP isoenzyme.