Cinacalcet monotherapy in neonatal severe hyperparathyroidism: a case study and review.

[familial hypocalciuric hypercalcemia]

Neonatal severe hyperparathyroidism (NSHPT ) is a severe form of familial hypocalciuric hypercalcemia characterized by severe hypercalcemia and skeletal demineralization . In most cases , NSHPT is due to biallelic loss -of-function mutations in the CASR gene encoding the calcium-sensing receptor (CaSR ), but some patients have heterozygous mutations . Conventional treatment consists of iv saline , bisphosphonates , and parathyroidectomy .The aim of this project was to characterize the molecular basis for NSHPT in an affected newborn and to describe the response to monotherapy with cinacalcet .Clinical and biochemical features were monitored as cinacalcet therapy was initiated and maintained . Genomic DNA was obtained from the proband and parents . The CASR gene was amplified by PCR and sequenced directly .The patient was a full-term male who developed hypotonia and respiratory failure soon after birth . He was found to have multiple fractures and diffuse bone demineralization , with a marked elevation in serum ionized calcium (1 .99 mmol /L ) and elevated serum levels of intact PTH (1154 pg /mL ); serum 25 -hydroxyvitamin D was low , and fractional excretion of calcium was reduced . The serum calcium level was not reduced by iv saline infusion . Based on an extensive family history of autosomal dominant hypercalcemia , a diagnosis of NSHPT was made , and cinacalcet therapy was initiated with a robust and durable effect . Molecular studies revealed a heterozygous R 185 Q missense mutation in the CASR in the patient and his father , whereas normal sequences for the CASR gene were present in the patient 's mother .We describe the first use of cinacalcet as monotherapy for severe hypercalcemia in a newborn with NSHPT . The rapid and durable response to cinacalcet suggests that a trial of calcimimetic therapy should be considered early in the course of NSHPT .

Diseases
Validation

Diseases presenting "loss-of-function mutations" symptom

achondroplasia

alpha-thalassemia

aromatase deficiency

child syndrome

cowden syndrome

dystrophic epidermolysis bullosa

epidermolysis bullosa simplex

erythropoietic protoporphyria

esophageal adenocarcinoma

familial hypocalciuric hypercalcemia

harlequin ichthyosis

hirschsprung disease

kallmann syndrome

kindler syndrome

lamellar ichthyosis

neonatal adrenoleukodystrophy

pendred syndrome

werner syndrome

x-linked adrenoleukodystrophy

This symptom has already been validated