====== Hypophosphatasia ======

Hypophosphatasia (HPT) and [[cleidocranial dysplasia]] (CCD) are rare [[genetic disorder]]s characterized by both defective [[ossification]] and [[bone mineralization]]. Patients usually present with [[craniosynostosis]] and [[cranial defects]] which in many cases require surgical [[repair]]. There is only 1 reported case of combined HPT and CCD in the [[literature]]. 

The reported case of Blionas et al. involves a 3.5-year-old girl with concomitant [[homozygous]] CCD and [[heterozygous]] HPT. The [[child]] had an extended cranial defect since birth which improved with the administration of [[Strensiq]] and was followed until preschool age. [[Bone defect]]s were relatively minor on revaluation. Due to the limited final defect, we decided not to intervene. In HPT-CCD patients, bone defects are overestimated due to [[osteomalacia]], and thus, management strategy should be less aggressive. They should undergo surgical [[repair]] with [[cranioplasty]] with the use of [[cement]] and/or [[titanium]] meshes in case of extended final defects
((Blionas A, Friehs GM, Zerris VA. Hypophosphatasia and cleidocranial dysplasia-a case report and review of the literature: the role of the neurosurgeon. Childs Nerv Syst. 2021 Jun 15. doi: 10.1007/s00381-021-05261-1. Epub ahead of print. PMID: 34131769.)).