Hypophosphatasia may lead to bone fragility: don't miss it.
Hypophosphatasia is an inheritable disorder characterised by defective bone mineralisation due to the impaired activity of tissue-non-specific alkaline phosphatase (AP). Clinical presentation ranges from stillbirth without mineralised bone to pathological fractures in late adulthood. During childhood, the main manifestations include rickets, growth delay and dental problems. Fractures and bone pain usually characterise the adult form. A 9-year-old girl was referred for repetitive fractures after minimal trauma. She had normal growth, normal sclerae, no rickets and minimal dental abnormalities. Her sister had also presented fractures. The proband, her sister and mother had low total and bone-specific AP levels and E435K mutation in exon 12 of the liver/bone/kidney AP gene. Low AP levels must lead to genetic analysis. Bone fragility and repetitive fractures may be symptoms of hypophosphatasia in childhood, which must not be neglected. Associated factors such as vitamin D or calcium deficiency must be prevented. In conclusion, hypophosphatasia must not be forgotten as an aetiological factor of repetitive fractures or bone pain in children and AP activity should be checked accurately.
Moulin
Pierre
P
Endocrinologie, Maladies Osseuses, Génétique et Gynécologie Médicale, Hôpital des Enfants, CHU de Toulouse, Toulouse Cedex 9, France.
Vaysse
Frédéric
F
Bieth
Eric
E
Mornet
Etienne
E
Gennero
Isabelle
I
Dalicieux-Laurencin
Sara
S
Baunin
Christiane
C
Tauber
Marie Thérèse
MT
De Gauzy
Jérôme Sales
JS
Salles
Jean Pierre
JP
D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood* / Q000235:genetics*; D002648:Child; D003937:Diagnosis, Differential; D005091:Exons; D005260:Female; D005598:Fractures, Spontaneous / Q000209:etiology* / Q000235:genetics; D006801:Humans; D007014:Hypophosphatasia / Q000097:blood / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D009035:Mothers; D009154:Mutation; D010375:Pedigree; D035781:Siblings
D000469:Alkaline Phosphatase