A case of hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome with a novel frameshift variant in GATA3, p.W10Cfs40, lacks kidney malformation.

Autosomal dominant hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome are typically diagnosed by manifestations of the three features with a positive family history. Our case carried a de novo variant in causative gene, GATA3, but presenting no renal dysplasia or family history. The phenotypic heterogeneity raises a caution for diagnosis.

Genetic alteration of ARMC5 in a patient diagnosed with meningioma and primary macronodular adrenal hyperplasia: a case report.

A monoallelic germline alteration of ARMC5 causes primary bilateral macronodular adrenal hyperplasia (PBMAH) with Cushing's syndrome via its subsequent somatic alteration on the other allele as the second hit. PBMAH is sometimes complicated with meningioma. Dependency of such a multi-organ disease on the second hit mechanism was reported before, but this finding has not been confirmed yet. We describe a case of a 65-year-old female with PBMAH, carrying a heterozygous germline alteration of ARMC5, p.R267*, complicated with meningioma associated with somatic loss of heterozygosity (LOH) of the unaffected allele. Pathogenic alterations of ARMC5 may also contribute to the development of meningioma by the two-hit mechanism.

Familial hypocalciuric hypercalcemia with a de novo heterozygous mutation of calcium-sensing receptor.

UNLABELLED: A de novo heterozygous inactivating mutation of calcium-sensing receptor (CASR) gene typically causes neonatal hyperparathyroidism (NHPT) with moderate hypercalcemia and hyperparathyroid bone disease. We present a case of asymptomatic hypocalciuric hypercalcemia with a de novo heterozygous mutation in CASR, S591C, which is primarily reported to be responsible for NHPT. A 54-year-old female was referred for investigation of asymptomatic hypercalcemia that was initially found in the 1980s but without a history of bone disease during the perinatal period. She had moderate hypercalcemia (12.4 mg/dl) and relative hypocalciuria (fractional extraction of calcium 1.07%) but normal intact parathyroid hormone and serum 1,25-dihydroxyvitamin D3. Pedigree analysis revealed that she carried a de novo heterozygous mutation of S591C, which she transmitted to an affected child with moderate hypercalcemia but not to other children, who had normal serum calcium levels. A de novo heterozygous CASR mutation that is responsible for NHPT may also present in individuals with asymptomatic hypocalciuric hypercalcemia. Caution is required when predicting course and outcome in a pedigree with CASR mutation, as well as incidental hypercalcemia, because of its variable phenotypes. LEARNING POINTS: The phenotype and severity of CASR mutations are thought to be dependent on genotypes.We report an asymptomatic case of the de novo heterozygous S591C mutation in CASR, which has previously been reported as a responsible mutation of NHPT with bone diseases.Variable phenotypes of CASR raise a cautionary note about predicting outcome by genotyping in a pedigree with CASR mutation.