Case Report: A rare form of congenital erythrocytosis due to SLC30A10 biallelic variants-differential diagnosis and recommendation for biochemical and genetic screening.

Congenital erythrocytosis recognizes heterogeneous genetic basis and despite the use of NGS technologies, more than 50% of cases are still classified as idiopathic. Herein, we describe the case of a 3-year-old boy with a rare metabolic disorder due to SLC30A10 bi-allelic mutations and characterized by hypermanganesemia, congenital erythrocytosis and neurodegeneration, also known as hypermanganesemia with dystonia 1 (HMNDYT1). The patient was treated with iron supplementation and chelation therapy with CaNa2EDTA, resulting in a significative reduction of blood manganese levels and erythrocytosis indexes. Although it couldn't be excluded that the patient's developmental impairment was part of the phenotypic spectrum of the disease, after three months from starting treatment no characteristic extrapyramidal sign was detectable. Our findings suggest the importance of assessing serum manganese levels in patients with unexplained polycythemia and increased liver enzymes. Moreover, we highlight the importance of extended genetic testing as a powerful diagnostic tool to uncover rare genetic forms of congenital erythrocytosis. In the described patient, identifying the molecular cause of erythrocytosis has proven essential for proper clinical management and access to therapeutic options.

Benign Intracranial Hypertension Due to Hypoparathyroidism: A Case Report.

Objective: The objective of this study is to present the rare case of a young girl with idiopathic intracranial hypertension secondary to hypoparathyroidism. Background: Idiopathic intracranial hypertension is a neurological syndrome characterized by elevated intracranial pressure (> 25 cmH2O) in the absence of intracerebral abnormalities or hydrocephalus. The pathophysiology of idiopathic intracranial hypertension is unknown, and rare cases of idiopathic intracranial hypertension secondary to hypoparathyroidism have been described. It is supposed that hypocalcemia causes decrease in the absorption of cerebrospinal fluid in arachnoidal granulations. Methods: The workup of the girl with idiopathic intracranial hypertension and hypoparathyroidism included physical examination, blood tests, diagnostic imaging, and lumbar puncture. Results: We present a 9-year-old female patient who was hospitalized for headache associated with nausea and vomiting for 3 weeks. She underwent an ophthalmologic examination that revealed papilledema. Lumbar puncture revealed an opening pressure of 65 cm H2O; cerebrospinal fluid analysis and brain computed tomography scan were normal. The patient started taking acetazolamide. Blood tests revealed hypocalcemia associated with high phosphorus level and undetectable PTH hormone, which led us to suspect hypoparathyroidism. She had never had cramps, paraesthesias, or tetany. Chvostek's and Trousseau's signs were positive. In the neck ultrasonography, parathyroids were not visible. Oral supplementation with calcitriol and calcium was started. Headache, nausea, and vomiting immediately disappeared after the lumbar puncture, and the papilledema improved gradually. Conclusions: Several anecdotal cases of idiopathic intracranial hypertension secondary to hypoparathyroidism have been described. However, our case report is of particular interest, since the child did not present with typical neurological hypoparathyroidism symptoms. Therefore, we recommend that hypoparathyroidism should be included in diagnostic investigations on children with clinical findings of idiopathic intracranial hypertension, because clinical manifestations of hypoparathyroidism are variable and may involve almost all organ systems.