Familial hypocalciuric hypercalcemia (FHH) type 1, caused by a heterozygous inactivating mutation of the gene encoding the calcium-sensing receptor (CaSR), is characterized by mild to moderate hypercalcemia, hypocalciuria and inappropriately normal or elevated parathyroid hormone (PTH). FHH must be differentiated from primary hyperparathyroidism (PHPT) because parathyroidectomy is ineffective in the former. Herein, we report a 39-year-old male patient with a 13-year history of asymptomatic PTH-dependent hypercalcemia (mean calcium of 2.88 mmol/l; reference range 2.15-2.55 mmol/l) and calcium-to-creatinine clearance ratio (Ca/Cr) ranging from 0.007 to 0.0198, which is consistent with either FHH or PHPT. Although a family history of hypercalcemia was negative, and PET-CT with fluorocholine was suggestive of a parathyroid adenoma, genetic analysis of the CaSR gene identified a heterozygous inactivating mutation NM_000388.4:c.1670G>A p. (Gly557Glu) in exon 6 and a polymorphism NM_000388.4:c.1192G>A p. (Asp398Asn) in exon 4. The G557E mutation has been previously reported in a Japanese family in which all family members with the mutation had Ca/Cr below 0.01 consistent with FHH. The biochemical profile of FHH and PHPT may overlap. Our FHH patient with a G557E CaSR mutation illustrates that the differential diagnosis can be difficult in an index case with no family history, (false) positive parathyroid imaging and higher calciuria than expected for FHH. Calcium intake, vitamin D status and bone resorption might have contributed to the Ca/Cr variations over a 13-year clinical follow up. This case thus emphasizes the irreplaceable role of genetic testing of the CaSR gene when clinical evaluation is inconclusive.

• MeSH
• diferenciální diagnóza MeSH
• dospělí MeSH
• hyperkalcemie krev   vrozené   diagnóza   diagnostické zobrazování   MeSH
• lidé MeSH
• následné studie MeSH
• PET/CT metody   MeSH
• primární hyperparatyreóza krev   diagnóza   diagnostické zobrazování   MeSH
• prognóza MeSH
• receptory "calcium-sensing" krev   MeSH
• vápník krev   MeSH
• vitamin D krev   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

Inconclusive preoperative imaging is a strong predictor of multiglandular parathyroid disease (MGD) in patients with primary hyperparathyroidism (PHPT). MGD was investigated in a cohort of 17 patients with PHPT (mean age 64.9 years, total calcium 2.75 mmol/l and parathyroid hormone (PTH) 113.3 ng/l) who underwent 18F-fluorocholine PET/CT (FCH) imaging before surgery. The initial MIBI SPECT scintigraphy (MIBI) and/or neck ultrasound were not conclusive or did not localize all pathological parathyroid glands, and PHPT persisted after surgery. Sporadic MGD was present in 4 of 17 patients with PHPT (24 %). In 3 of 4 patients with MGD, FCH correctly localized 6 pathological parathyroid glands and surgery was successful. Excised parathyroid glands were smaller (p <0.02) and often hyperplastic in MGD than in single gland disease. In two individuals with MGD, excision of a hyperplastic parathyroid gland led to a false positive decline in intraoperative PTH and/or postoperative serum calcium. Although in one patient it was associated with partial false negativity, parathyroid imaging with FCH seemed to be superior to neck ultrasound and/or MIBI scintigraphy in MGD.

• MeSH
• lidé středního věku MeSH
• lidé MeSH
• paratyreoidea diagnostické zobrazování   patologie   chirurgie   MeSH
• PET/CT metody   MeSH
• primární hyperparatyreóza * diagnostické zobrazování   patologie   chirurgie   MeSH
• senioři MeSH
• technecium 99mTc sestamibi MeSH
• vápník MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• avitaminóza diagnóza   komplikace   krev   MeSH
• diagnostické techniky endokrinologické normy   MeSH
• financování organizované MeSH
• konsensus MeSH
• lidé MeSH
• mutační analýza DNA metody   MeSH
• parathormon krev   MeSH
• primární hyperparatyreóza diagnóza   genetika   komplikace   MeSH
• protoonkogenní proteiny genetika   MeSH
• receptory "calcium-sensing" genetika   MeSH
• vitamin D krev   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• souhrny MeSH