Perinatal hypophosphatasia

Abstract

Hypophosphatasia, also known as alkaline phosphatase deficiency, is a rare congenital metabolic disorder characterised by early bone and dental defects. First reports on hypophosphatasia date back to 1950s. The prevalence of the disorder in Europe is 1:300,000 births; data on the prevalence in Poland is missing. An abnormal structure of the region coding for the ALPL gene, which is responsible for producing tissue-nonspecific alkaline phosphatase, is the main cause of clinical symptoms. Consequently, there is a significant deficiency in the activity or even absence of this enzyme. Due to the heterogeneous clinical expression of hypophosphatasia, multiple clinical forms of the disorder, which vary in their mode of inheritance and prognosis, have been described, including rare and sporadically reported perinatal forms. There are ongoing studies on the aetiology, diagnosis and treatment of different clinical forms of hypophosphatasia. We present a case report of perinatal hypophosphatasia diagnosed in the Department of Neonatology at the University Clinical Hospital in Wroclaw, with particular focus on the implemented diagnostic-therapeutic process and possible complications in the affected child during the stay in the neonatal intensive care unit. We also performed a literature review to present a wider picture of the disorder belonging to the group of the so-called rare diseases. We described current diagnostic and treatment possibilities in hypophosphatasia, based on the latest clinical trials, as well as the costs of treatment using Strensiq, the only alkaline phosphatase analogue available on the market.