Newly discovered mutations in the GALNT3 gene causing autosomal  recessive hyperostosis-hyperphosphatemia syndrome.
OBJECTIVE
Periosteal new bone formation and cortical hyperostosis often suggest an initial diagnosis of bone malignancy or osteomyelitis. In the present study, we investigated the cause of persistent bone hyperostosis in the offspring of two consanguineous parents.


METHODS
Clinical assessment, imaging, and direct sequencing were used to elucidate the etiology of the condition seen in the patient.


RESULTS
Radiological examination revealed periosteal reaction, diaphysitis, and cortical hyperostosis, suggesting osteomyelitis or a bone neoplasm. The clinical and radiological features were also reminiscent of hyperostosis with hyperphosphatemia (HHS), a rare autosomal recessive disease manifesting with recurrent, transient, and painful swelling of the long bones. The identification of two novel heterozygous pathogenic mutations in the GALNT3 gene confirmed a diagnosis of HHS.


CONCLUSIONS
Molecular analysis represents an invaluable tool in the differential diagnosis of persistent cortical hyperostosis.
Gok
Faysal
F
Department of Pediatric Nephrology, Gulhane Military Medical School, Ankara, Turkey.
Chefetz
Ilana
I
Indelman
Margarita
M
Kocaoglu
Murat
M
Sprecher
Eli
E
D002114:Calcinosis / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D002648:Child; D003241:Consanguinity; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015576:Hyperostosis / Q000000981:diagnostic imaging / Q000235:genetics* / Q000378:metabolism; D054559:Hyperphosphatemia / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism; D008297:Male; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics*; D011859:Radiography; D013577:Syndrome; D013977:Tibia / Q000000981:diagnostic imaging; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D017350:N-Acetylgalactosaminyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase