ESPE Abstracts

Background: Short stature is a common reason for pediatric endocrinologist consultation, but in many cases, no cause can be identified. Childhood hypophosphatasia has widely variable clinical features from short stature to low bone mineral density with skeletal deformities, and the place of serum alkaline phosphatase (ALP) activity assay could be raised as etiological exploration is not consensual

Objective and hypotheses: The aim of our study was to evaluate the ALP levels in a cohort of short stature children.

Method: Children referred in our teaching hospital of Rouen for evaluation of short stature (height <−2 S.D., or decreased growth velocity >1 S.D.) from the 1st January 2010 to 31th December 2014 were included in the present retrospective study. Children were eligible when a GH stimulation test and an ALP assay were performed. Anamnestic, auxological, biological, and radiological data were collected.

Results: 167 children (101 boys and 66 girls) were included at a mean age referral of 8.6 years old (0.5–18) with a mean height at −2.4 S.D. (−5 to 0.5). Whereas the majority of patients revealed normal ALP level, 12 showed low ALP levels (i.e. <120 U/ml) (67–119), among whom four had a somatotropin deficiency. None of them demonstrated radiological abnormalities or skeletal deformations. Seven among the 12 patients had a second ALP assay revealing for five of them normal ALP level, mostly concomitant with an acceleration of growth velocity. No controls were available up to now for the others children.

Conclusion: Abnormal ALP activity was observed in 7.1% studied patients suggesting that hypophosphatasia could be a rare cause of short stature and that ALP assay need to be performed until further studies in larger population confirm this hypothesis.