Retrospective diagnostics of hypophosphatasia in children
Sosnina I.B.¹, Sukcheev M.B., Ivashikina T.M.¹, Snegova E.V.¹, Pashkova V.P.¹, Klimenkova O.A.¹, Pervunina T.M.^2
1 Consultative Diagnostic Center for Children, St. Petersburg
² V.A. Almazov Federal North-West Medical Research Center, St. Petersburg

Hypophosphatasia is a rare inherited life-threatening condition resulting from the deficiency of tissue-specific alkaline phosphatase (AP) encoded by APL gene. This disorder with specific clinical manifestations is characterized by low serum activity of AP. The occurrence of hypophosphatasia varies among the countries, its estimated rate in Russia is 1 per 100,000 population. The most common symptoms of hypophosphatasia in children are defective bone mineralization, rachitic skeletal deformations, low muscle tonus, fatigue after physical activity, pains (myalgia, ossalgia), recurrent bone fractures, losing teeth, respiratory disorders, pyridoxine-dependent seizures, hypocalcaemia, and nephrocalcinosis. Multiple organ dysfunction and severe metabolic disorders lead to life-threatening conditions. Early hypophosphatasia mortality is 50-100%.
The publication addresses the outcomes of retrospective study on the identification of patients with this rare disease. Diagnostic algorithm considers current reference values of tissue-nonspecific AP activity in children and includes test database screening and clinical symptom assessment. As a result, three patients with genetically verified hypophosphatasia were identified. This algorithm can be used for precise cost-effective diagnosis of hypophosphatasia in other clinics.

Key words: hypophosphatasia, HPP, tissue-nonspecific alkaline phosphatase, rickets like conditions, skeleton, children, diagnostics, skeletal deformations, stunting, genetic diagnostics, ALPL.

For citation: Sosnina I.B., Sukcheev M.B., Ivashikina T.M. et al. Retrospective diagnostics of hypophosphatasia in children // RMJ. 2016. № 26. P. 1778–1781.