Endocrine Abstracts

Background: Chronic hypophosphatemia in children mimics diverse conditions and may be underpinned by genetic disorders (e.g. X-linked hypophosphatemia), primary hyperthyroidism, tubular disorders (Fanconi syndrome) and neoplasia. Severe sequelae like rickety deformities of the skeleton, mental and physical retardation, osteoporosis and osteomalacia,etc require prompt diagnosis and treatment. Here we present a case report of untreated chronic hypophosphatemia mimicking ketoacidosis on the admission.

Case presentation: A male patient of 3 years old presented with vomiting, shortness of breath and altered mental status. He had history of poor weight gain since 2 months old, bone deformities and loss of unassisted walking since 1.4 y.o. Family history was remarkable for bowing of lower extremities in his aunt. Taking into account clinical presentation and ketonuria, the differential diagnosis with diabetic ketoacidosis was conducted. On examination: physical and mental retardation, stigma of disembryogenesis, rickety deformities of the trunk and extremities. Height - 77 cm; weight - 7.9 kg, respectively. Laboratory findings included hypochromic anemia (I degree), normal glycemia, hypophosphatemia, normal serum Ca, elevated alkaline phosphatase, high parathyroid hormone level, secondary hypothyroidism. On the X-ray: osteoporosis. In view of the abovementioned data a provisional diagnosis ‘chronic hypophosphatemia’ was established. As other causes were ruled out, a hereditary form of hypophosphatemia was suspected. To specify the diagnosis the patient was referred to a genetic counseling.

Conclusions: Physicians should be suspicious of hereditary forms of hypophosphatemia when a patient has abovementioned clinical presentation, as prompt diagnosis and treatment may compensate for physical and mental developmental delay, and prevent surgery.