Sinus Hypoplasia and Intracranial Hypertension in Pycnodysostosis (SHIHP): A New Disease Process?

Introduction Pycnodysostosis (PDO) is a rare autosomal recessive lysosomal storage disease of the bone caused by a mutation in a gene mapped to chromosome 1q21 that codes for the enzyme cathepsin K (CTSK). Pycnodysostosis (Greek: pycnos = dense; dys = defective; osteon = bone) was first coined in 1962 by Maroteaux and Lamy [1], although the first case fitting the description may have been reported as early as 1923 [2]. Patients with PDO have short stature, increased bone density and are prone to fractures [1-3]. They usually have macrocephaly with frontal and parietal bossing, an open anterior fontanelle and patent cranial sutures, an obtuse Abstract