scholarly journals Familial Hypocalciuric Hypercalcemia in an Index Male: Grey Zones of the Differential Diagnosis From Primary Hyperparathyroidism in a 13-Year Clinical Follow up

2020 ◽  
pp. S321-S328
Author(s):  
K. ZAJÍČKOVÁ ◽  
M. DVOŘÁKOVÁ ◽  
J. MORAVCOVÁ ◽  
J. VČELÁK ◽  
D. GOLTZMAN

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.

Author(s):  
Tivya Kulasegaran ◽  
Pranav Kumar

Familial hypocalciuric hypercalcaemia (FHH) is a rare genetic autosomal dominant disorder, with 3 variants described. An inactivating mutation in the calcium sensor receptor (CASR) gene causes the subtype 1, which represents 65% of the cases. Inactivation of Ca-sensing receptors (CaSR) can also lead to hypercalcemia associated with increased parathyroid hormone (PTH) secretion.[1] It is characterised by causes mild asymptomatic hypercalcemia[2] and hypocalciuria with normal or elevated PTH. FHH is generally asymptomatic and treatment is not needed. Differential diagnosis with primary hyperparathyroidism (PHPT) is crucial and based on calcium-creatinine clearance ratio (CCCR), which, when under 0.02 points to the diagnosis of FHH.[3] Genetic test is necessary for confirmation.[4]


2021 ◽  
Author(s):  
David Taïeb ◽  
Adele Lasbleiz ◽  
Nunzia Cinzia Paladino ◽  
Pauline Romanet ◽  
Frédéric Castinetti ◽  
...  

Abstract Familial hypocalciuric hypercalcemia (FHH) is an autosomal dominant genetic disorder classically characterized by lifelong mild-to-moderate asymptomatic hypercalcemia with inappropriately normal to elevated serum parathyroid hormone (PTH) concentrations and hypocalciuria, best expressed by a urine calcium-to-creatinine clearance ratio (CCCR)<0.01[1,2]. FHH prevalence is estimated between 1:10 000 to 1:100 000[3,4]. In 60% of cases, FHH is due to CASR inactivating mutation[5]. More rarely FHH is due to AP2S1 or GNA11 inactivating mutation, both genes encoding for proteins involved downstream of CASR activation[6]. These molecular alterations are found in all parathyroid cells, explaining disease persistence following partial parathyroidectomy and the ineffective surgical management of these patients. FHH phenotypes could however overlap with primary hyperparathyroidism (PHPT). Indeed, even if patients with FHH are currently asymptomatic, some of them present chondrocalcinosis, kidney stones or bone fracture and very high level of PTH or calcemia[7]. Nonetheless, the distinction has to be adressed since the therapeutic approach significantly differs between these two conditions. Surgery is usually recommended for PHPT[8] while follow-up is preferred in the latter case[9,10]. We report and discuss 7 cases, 6 out 7 being operated for a presumed PHPT.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A182-A183
Author(s):  
Dalal S Ali ◽  
Karel Dandurand ◽  
Aliya Aziz Khan

Abstract Background: Differentiation between familial hypocalciuric hypercalcemia (FHH) and primary hyperparathyroidism (PHPT) can be challenging in certain cases in the absence of DNA analysis of the calcium sensing receptor gene. The distinction between those two clinical entities with overlapping biochemical features therefore relies on the calcium to creatinine clearance ratio (CCCR), which is expected to be low in FHH (&lt;0.01 in 80% of cases and between 0.01 and 0.02 in approximately 20% of patients)1. Patients with PHPT usually have a CCCR of&gt;= 0.02. A lower CCCR between 0.01 and 0.02 can be seen in approximately 20% of patients1,2and is more commonly seen in the presence of vitamin D insufficiency, impaired renal function, low calcium intake or being of African descent. It is advised to stop drugs which can contribute to hypercalcemia and lower the CCCR such as thiazide diuretics prior to evaluating the CCCR. Clinical Case: A 56-year-old lady was referred for evaluation of persistent hypercalcemia post parathyroidectomy and fatigue. She had mildly elevated ionized serum calcium (iCa) and a mid-normal PTH with a CCCR of 0.024. She had a normal BMD with no prior fragility fractures and passed a kidney stone prior to her presentation. Physical exam was unremarkable. She had previously travelled to Tampa and had a subtotal parathyroidectomy 3 glands (RU, LU, RL) for a possible diagnosis of PHPT, tissue biopsy showed hyperplastic parathyroids. Her MEN1 gene analysis was negative for MEN1 mutation and MRI of the abdomen was unremarkable. Her mother had a diagnosis of PHPT and osteoporosis. The iCa remained mildly elevated at 1.43 mmol/L (1.15–1.3) with a 24 hr urinary CCCR at 0.024 and a mid-normal PTH of 4.4 pmol/L (1.6–6.9). Her eGFR was 104 mls/min, 25 vitamin D 82 nmol/L (75–250), 1,25 dihydroxy vitamin D 122 pmol/L (60–206), PO4 0.90 mmol/L (0.8–1.45) and alkaline phosphatase 46 U/L (35–120) were all normal. She continued to have mild symptoms of hypercalcemia and her bone scan was negative for underlying skeletal pathology. DNA studies for mutations in the CaSR gene were completed. This confirmed the presence of a heterozygous loss of function mutation in the CASR gene at c493-2A&gt;G which appears to be pathogenic. Conclusion: The CCCR is useful in differentiating PHPT from FHH however in certain cases of FHH the CCCR may be higher then expected and we have now confirmed the presence of FHH with a molecular diagnosis in a patient with a CCCR as high as 0.02. References: 1 Gunn, IR, Gaffney, D. Clinical and laboratory features of calcium-sensing receptor disorders: a systematic review. Ann Clin Biochem 2004; 41:441–58 2 Stephen J. Marx, Letter to the Editor: Distinguishing Typical Primary Hyperparathyroidism From Familial Hypocalciuric Hypercalcemia by Using an Index of Urinary Calcium, The Journal of Clinical Endocrinology & Metabolism, 2015


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Andrea K Juneau ◽  
Adwoa Opoku-Boateng ◽  
Gabriel Ikponmosa Uwaifo

Abstract BACKGROUND: Primary hyperparathyroidism (pHT) is one of the most common causes of hypercalcemia. About 10% of these patients have a familial cause of which MEN and the hyperparathyroid-jaw tumor syndrome (HJTs) are most common. Familial hypocalciuric hypercalcemia (FHH) due to loss of function mutations of the calcium sensing receptor (CASR) gene is an important familial mimic of this that needs to be distinguished. Beyond this are still a group of patients with familial isolated primary hyperparathyroidism (FIpHT). Recognition of this entity is important because of the different prognostic and surgical treatment strategy for their management compared to regular sporadic pHT. Clinical Case: A 58 yr old postmenopausal lady on topical HRT was referred for thyroid nodular disease. Her initial lab tests showed primary hyperparathyroidism with mild hypercalcemia. Her initial neck sonogram showed multiple benign appearing nodules that did not warrant biopsy. There was a history of hypothyroidism in her mother and thyroid cancer in a maternal cousin. In addition, her father and two sons have history of hypercalcemia that required repeated hospital admissions for treatment. Her two daughters to date have had no hypercalcemia, nephrolithiasis nor thyroid problems. There was no family history of jaw, renal nor brain or pituitary tumors and no history of severe dyspeptic disease nor familial cancers. She had hypercalciuria, normal bone density and non-obstructive nephrolithiasis. MEN-1 gene testing was normal. Parathyroid scan suggested a possible right sided parathyroid lesion and she had elective parathyroidectomy of an ectopic right parathyroid that was hypercellular on histology. The intra-operative PTH dropped following the lesion extraction by ~ 51%. Post operatively the patient’s mild pHT and hypercalcemia persists but imaging studies have been unrevealing. Further genetic testing for other possible etiologies of familial pHT were -ve for HJTs but revealed a novel somatic mutation of the CASR gene; c.1868G&gt;A (p.Gly623Asp) whose present significance is unclear. This variant has been described in one family with FHH but In silico predictive analyses of the mutation suggests a possible deleterious effect. Given her known family history of symptomatic hypercalcemia this novel mutation appears to be a hitherto unrecognized cause for FIpHT. The patient is presently being conservatively managed and monitored. Conclusion: While familial pHT is relatively uncommon its recognition is important as it can inform planned surgical intervention and expected prognosis for anticipated cure. While MEN and HJTs are the most common etiologies for familial pHT other possibilities need to considered when the history suggests possible FIpHT and our case highlights a novel CASR mutation as diagnostic consideration.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
S. A. Ghaznavi ◽  
N. M. A. Saad ◽  
L. E. Donovan

Background. Primary hyperparathyroidism (PHPT) and Familial Hypocalciuric Hypercalcemia (FHH) result in different maternal and fetal complications in pregnancy. Calcium to creatinine clearance ratio (CCCR) is commonly used to help distinguish these two conditions. Physiological changes in calcium handling during pregnancy and lactation can alter CCCR, making it a less useful tool to distinguish PHPT from FHH. Cases. A 25-year-old female presented with hypercalcemia and an inappropriately normal PTH. Her CCCR was 0.79% before pregnancy and rose to 1.99% in her second trimester. The proband’s mother and neonate had asymptomatic hypercalcemia. Genetic analysis revealed a CaSR mutation consistent with FHH. A 19-year-old female presented with a history of nephrolithiasis who underwent emergent caesarean section at 29 weeks of gestation for severe preeclampsia. At delivery, she was diagnosed with hypercalcemia with an inappropriately normal PTH and a CCCR of 2.67%, which fell to 0.88% during lactation. Parathyroidectomy cured her hypercalcemia. Pathology confirmed a parathyroid adenoma. Conclusion. These cases illustrate the influence of pregnancy and lactation on renal calcium indices, such as the CCCR. To avoid diagnostic error of women with hypercalcemia during pregnancy and lactation, calcium biochemistry of first-degree relatives and genetic testing of select patients are recommended.


Medunab ◽  
2022 ◽  
Vol 24 (3) ◽  
pp. 347-352
Author(s):  
Edwin Antonio Wandurraga-Sánchez ◽  
Mario Alejandro Buitrago-Gómez ◽  
María Camila Uribe-Forero ◽  
Nestor Andrés Díaz-Posada ◽  
María Camila Amaya-Muñoz

Introduction. Familial hypocalciuric hypercalcemia is a rare inherited calcium metabolism disorder in which an alteration of the parathyroid hormone secretion set-point causes hypercalcemia with relative hypocalciuria. Some data suggest that its prevalence is around 74.1 per 100,000 inhabitants. Often, patients are asymptomatic. However, they can develop mild symptoms and an overactive parathyroid adenoma, its main differential diagnosis. The objective was to describe a patient’s case and highlight the importance of clinical suspicion and diagnosis to avoid unnecessary surgical neck explorations for parathyroid adenomas. Case report. This is the case of a 40-year-old man with a biochemical profile compatible with primary hyperparathyroidism with anatomical and functional images negative for adenoma and a calcium/creatinine clearance ratio below 0.001, considering familial hypocalciuric hypercalcemia. Genetic studies evidence a mutation in the calcium sensor receptor gene and confirm the diagnosis. Discussion. Familial hypocalciuric hypercalcemia’s main differential diagnosis is an overactive parathyroid adenoma. For both, mild or no symptoms may be present; serum calcium exceeds the upper limit, and parathormone is more than 25pg/ml. The calcium/creatinine clearance ratio should be used to differentiate one from the other and avoid unnecessary surgical neck explorations. Besides the lack of information on this topic, evidence supports the use of calcimimetics to treat symptomatic hypercalcemia. Conclusions. Patients with mild hypercalcemia with parathyroid hormone readings above 25pg/ml and a calcium/creatinine clearance ratio below 0.001, or patients with primary hyperparathyroidism with negative imaging, should not undergo surgical neck explorations. In these cases, familial hypocalciuric hypercalcemia is a reliable diagnosis; Cinacalcet may be administered in cases of symptomatic hypercalcemia.


2021 ◽  
Vol 9 (1) ◽  
pp. e001948
Author(s):  
Marion Denos ◽  
Xiao-Mei Mai ◽  
Bjørn Olav Åsvold ◽  
Elin Pettersen Sørgjerd ◽  
Yue Chen ◽  
...  

IntroductionWe sought to investigate the relationship between serum 25-hydroxyvitamin D (25(OH)D) level and the risk of type 2 diabetes mellitus (T2DM) in adults who participated in the Trøndelag Health Study (HUNT), and the possible effect modification by family history and genetic predisposition.Research design and methodsThis prospective study included 3574 diabetes-free adults at baseline who participated in the HUNT2 (1995–1997) and HUNT3 (2006–2008) surveys. Serum 25(OH)D levels were determined at baseline and classified as <50 and ≥50 nmol/L. Family history of diabetes was defined as self-reported diabetes among parents and siblings. A Polygenic Risk Score (PRS) for T2DM based on 166 single-nucleotide polymorphisms was generated. Incident T2DM was defined by self-report and/or non-fasting glucose levels greater than 11 mmol/L and serum glutamic acid decarboxylase antibody level of <0.08 antibody index at the follow-up. Multivariable logistic regression models were applied to calculate adjusted ORs with 95% CIs. Effect modification by family history or PRS was assessed by likelihood ratio test (LRT).ResultsOver 11 years of follow-up, 92 (2.6%) participants developed T2DM. A higher risk of incident T2DM was observed in participants with serum 25(OH)D level of<50 nmol/L compared with those of ≥50 nmol/L (OR 1.72, 95% CI 1.03 to 2.86). Level of 25(OH)D<50 nmol/L was associated with an increased risk of T2DM in adults without family history of diabetes (OR 3.87, 95% CI 1.62 to 9.24) but not in those with a family history (OR 0.72, 95% CI 0.32 to 1.62, p value for LRT=0.003). There was no effect modification by PRS (p value for LRT>0.23).ConclusionSerum 25(OH)D<50 nmol/L was associated with an increased risk of T2DM in Norwegian adults. The inverse association was modified by family history of diabetes but not by genetic predisposition to T2DM.


2021 ◽  
Author(s):  
Gema Ariceta ◽  
Fadi Fakhouri ◽  
Lisa Sartz ◽  
Benjamin Miller ◽  
Vasilis Nikolaou ◽  
...  

ABSTRACT Background Eculizumab modifies the course of disease in patients with atypical hemolytic uremic syndrome (aHUS), but data evaluating whether eculizumab discontinuation is safe are limited. Methods Patients enrolled in the Global aHUS Registry who received ≥1 month of eculizumab before discontinuing, demonstrated hematologic or renal response prior to discontinuation and had ≥6 months of follow-up were analyzed. The primary endpoint was the proportion of patients suffering thrombotic microangiopathy (TMA) recurrence after eculizumab discontinuation. Additional endpoints included: eGFR changes following eculizumab discontinuation to last available follow-up; number of TMA recurrences; time to TMA recurrence; proportion of patients restarting eculizumab; and changes in renal function. Results We analyzed 151 patients with clinically diagnosed aHUS who had evidence of hematologic or renal response to eculizumab, before discontinuing. Thirty-three (22%) experienced a TMA recurrence. Univariate analysis revealed that patients with an increased risk of TMA recurrence after discontinuing eculizumab were those with a history of extrarenal manifestations prior to initiating eculizumab, pathogenic variants, or a family history of aHUS. Multivariate analysis showed an increased risk of TMA recurrence in patients with pathogenic variants and a family history of aHUS. Twelve (8%) patients progressed to end-stage renal disease after eculizumab discontinuation; 7 (5%) patients eventually received a kidney transplant. Forty (27%) patients experienced an extrarenal manifestation of aHUS after eculizumab discontinuation. Conclusions Eculizumab discontinuation in patients with aHUS is not without risk, potentially leading to TMA recurrence and renal failure. A thorough assessment of risk factors prior to the decision to discontinue eculizumab is essential.


2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
B. Dhamija ◽  
D. Kombogiorgas ◽  
I. Hussain ◽  
G. A. Solanki

Background. Primary hyperparathyroidism in childhood is a very rare entity, often being diagnosed late after the onset of its presenting symptoms. It most commonly affects patients in their fourth decade of life and beyond. The inclusion of primary hyperparathyroidism in the differential diagnosis is necessary when evaluating patients presenting with nonspecific symptoms such as polyuria, fatigue, weight loss, abdominal pain, nausea, and vomiting.Methods. We report the case of an eleven-year-old girl presenting with three years history of headaches, visual disturbance, along with episodes of emotional lability. Neuroimaging confirmed a large posterior fossa arachnoid cyst. It was decided to manage this lesion conservatively with surveillance. Only after further hospital admissions with recurrent loss of consciousness, dizziness, and nausea to add to her already existing symptoms, a full biochemical and endocrine assessment was performed to look for more specific causes for her presentation. These pointed to a diagnosis of primary hyperparathyroidism.Conclusions. The inclusion of primary hyperparathyroidism in the differential diagnosis should be considered when evaluating paediatric patients presenting with nonspecific (neurological, gastrointestinal, and renal) symptoms in order to establish a prompt diagnosis of the disorder and to avoid severe complications of prolonged hypercalcaemia and end-organ damage.


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