SUN-521 Intracranial Calcifications Outside the Basal Ganglia at Presentation of Barakat Syndrome

Abstract

Abstract Hypoparathyroidism-sensorineural Deafness-Renal dysgenesis (HDR, or Barakat) syndrome is an uncommon cause of hypoparathyroidism, representing fewer than 200 documented cases in the literature worldwide. Individuals with HDR have variable penetrance and a range of phenotypes. While basal ganglia calcifications are known to occur with chronic hypoparathyroidism, they are less common in children and intracranial calcifications outside the basal ganglia, to our knowledge, have not been documented in HDR syndrome. Case presentation: A 10 year-old boy with a history of sensorineural deafness and attention deficit hyperactivity disorder presented after a new-onset seizure during a basketball game. His initial total serum calcium level of 5.9 mg/dl with an albumin level of 4.4 mg/dl, serum phosphorus was 7.0 mg/dl, and normal creatinine for age. PTH level was 2 pg/ml. He was started on calcitriol and calcium supplementation. There was no prior personal nor family history of hypocalcemia, nephrolithiasis, deafness nor renal problems. A head CT showed calcifications in the basal ganglia as well as at the temporal and frontoparietal gray-white matter junction and thalamus. Parathyroid antibody testing was negative. Subsequent genetic analysis of the GATA3 gene indicated heterozygosity for c.790T>C causing a missense mutation (p.Cys264Arg), that has been reported to cause HDR due to altered DNA binding affinity of the zinc finger component of GATA3. On renal ultrasound kidneys were in the 8th-13th percentile for size, raising the possibility of mild hypoplasia. Post-treatment urine Calcium-to-Creatinine ratio was 0.105. We describe a case of HDR in childhood who presented with seizures and very rare pediatric finding of calcifications in the basal ganglia as well as additional intracranial calcification in the thalamus and temporal and frontoparietal gray-white matter junction, which to our knowledge have not previously been described with HDR Syndrome. This case highlights important features of this disorder including severe intracranial calcifications and morphologic renal anomalies. HDR patients are at high risk for renal impairment, which is a key prognostic factor. Thus, careful monitoring of renal function, avoidance of nephrotoxins and of excessive calciuria during hypoparathyroidism management are necessary.