An unusual combination of neurological manifestations and sudden vision loss in a child with familial hyperphosphatemic tumoral calcinosis

We report a child with hyperphosphatemia who presented with multiple episodes of neurologic dysfunction involving lower motor neuron facial nerve palsy along with sequential visual loss. He also had an episode of stroke. There was an extensive metastatic calcification of soft tissue and vasculature. Hyperphosphatemia with normal serum alkaline phosphatase, calcium, parathyroid hormone, and renal function was noted. He was managed with hemodialysis and sevelamer (3 months) without much success in reducing serum phosphate level, requiring continuous ambulatory peritoneal dialysis (3 years). Intact fibroblast growth factor 23 (FGF23) was undetectable, with C-terminal FGF23 fragments significantly elevated (2575 RU/ml, normal <180 RU/ml). Sequencing demonstrated homozygous c.486C >A (p.N162K) mutation in FGF23 exon 3, confirming the diagnoses of primary FGF23 deficiency, the first case to be reported from India.

Source: Annals of Indian Academy of Neurology - June 30, 2019 Category: Neurology Authors: Lokesh Lingappa Shoji Ichikawa Amie K Gray Dena Acton Michael J Evans Rajsekara Chakravarthi Madarasu Ramesh Kekunnaya Sirisharani Siddaiahagari Source Type: research