ESPE Abstracts

Introduction: Barakat Syndrome (HDR Syndrome) is characterized by hypoparathyroidism (H), sensorineural deafness (D) and renal disease (R) caused by an autosomal dominant inheritance, being mostly associated to deletions in chromosome 10p14 or mutations in GATA3 gene.

Case Report: A 9 years old male was admitted at an emergency complaining of upper and lower limbs pain and contractures that progressed with periodic tetany, lasting for four months years. At examination presented hypertonia, muscle contraction of the upper and lower limbs, pain mobilization of both hands, feet and hip joints. Laboratory assessment demonstrated low total serum calcium (5.59mg/dL, reference value (RV): 8.2 to 10.3mg/dL), low parathyroid hormone (PTH) concentration (2.38pg/mL, RV: 15 to 65pg/mL), low serum phosphorus: 1.4 mg/dL (RV: 4-7 mg/dL), creatinine 1.17 mg/dL (Estimated Glomerular Filtration Rate-eGFR: 68 ml/min/1.73m² - RV: >90 ml/min/1.73m2), elevated calciuria (0.72 mg/mg, RV: <0.21 mg/mg) and albuminuria (41.8 mg/L, RV: <29 mg/L). The abdominal ultrasound evidenced diffuse increase in cortical echogenicity of the kidneys. The audiogram identified sensorineural hearing impairment. The clinical manifestations and laboratory findings of renal disease (tubulopathy), hypoparathyroidism and sensorineural hearing impairment strongly suggested Barakat Syndrome. Treatment was initiated with Teriparatide (20mcg/day, once a day), calcitriol and calcium carbonate supplementation, hydrochlorothiazide, Scholl's solution and elemental phosphorus. After three years of follow-up, the patients progressed with worsening of hearing impairment and renal function, bone mineral density reduction and nephrocalcinosis.

Discussion: The HDR syndrome prevalence is unknown and is defined by different phenotypic expression (HDR, HD, DR, HR and D), being more frequently associated to sensorineural deafness (96.7%), hypoparathyroidism (93.3%) and renal disease (72.2%), all manifestations presented in our case. The molecular diagnosis (GATA3 testing) is important to confirm the syndrome in patients with isolated form of deafness or renal disease especially when there is another family member affected.