Prevalence and significance of NALP5 autoantibodies in patients with idiopathic hypoparathyroidism

Hypoparathyroidism: Genetics and Diagnosis

This narrative report summarizes diagnostic criteria for hypoparathyroidism and describes the clinical presentation and underlying genetic causes of the nonsurgical forms. We conducted a comprehensive literature search from January 2000 to January 2021 and included landmark articles before 2000, presenting a comprehensive update of these topics and suggesting a research agenda to improve diagnosis and, eventually, the prognosis of the disease. Hypoparathyroidism, which is characterized by insufficient secretion of parathyroid hormone (PTH) leading to hypocalcemia, is diagnosed on biochemical grounds. Low albumin-adjusted calcium or ionized calcium with concurrent inappropriately low serum PTH concentration are the hallmarks of the disease. In this review, we discuss the characteristics and pitfalls in measuring calcium and PTH. We also undertook a systematic review addressing the utility of measuring calcium and PTH within 24 hours after total thyroidectomy to predict long-term hypoparathyroidism. A summary of the findings is presented here; results of the detailed systematic review are published separately in this issue of JBMR. Several genetic disorders can present with hypoparathyroidism, either as an isolated disease or as part of a syndrome. A positive family history and, in the case of complex diseases, characteristic comorbidities raise the clinical suspicion of a genetic disorder. In addition to these disorders' phenotypic characteristics, which include autoimmune diseases, we discuss approaches for the genetic diagnosis. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The study on the risk of other endocrine glands autoimmune diseases in patients with type 1 diabetes mellitus

To study the changes of pancreas, thyroid, adrenal, parathyroid and gonadal organ-specific antibodies in patients with type 1 diabetic patients and to explore the risk of development to other endocrine gland autoimmune diseases.Fifty one patients with type 1 diabetes mellitus were selected. ELISA was used to detect islet, adrenal gland, Parathyroid, gonadal organ-specific antibody levels, the level of thyroid-related antibodies by lectrochemiluminescence.Compared with the healthy control group, the levels of the 17-α-OHAb, 21-OHAb, NALP5Ab, P450sccAb, and CaSRAb in the T1DM group were significantly higher. GADAb-positive patients were more likely to have TPOAb-positive patients than GADAb-negative patients, and the positive rate of 2 thyroid antibodies in GADAb-positive patients was significantly higher than that in GADAb-negative patients. The presence of these antibodies is related to the age of onset of type 1 diabetes or Patient age. In combination with 1 or 2 islet antibody-positive patients, the combined non-islet antibody positive rate was higher than that of islet antibody-negative patients.Patients with type 1 diabetes with other autoimmune diseases at risk significantly increased compared with normal, of which the most common thyroid autoimmune disease, thyroid antibodies and hormone levels should be routinely detected at the first visit and long-term follow-up.

Central Immune Tolerance of T and B Cells in Patients With Idiopathic Hypoparathyroidism, T1D, and Autoimmune Thyroiditis

CONTEXT

Pathogenesis of idiopathic hypoparathyroidism (IH) is under investigation. Abnormalities in central immune tolerance have yet not been investigated in this condition. T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs), formed during receptor gene rearrangements, are tools to assess central T- and B-cell output.

OBJECTIVE

We assessed the number of circulating TRECs and KRECs in patients with IH, autoimmune type 1 diabetes (T1D), and autoimmune thyroiditis (ATs) and healthy controls (HCs).

DESIGN

Comparative case-control at tertiary care center.

SUBJECTS AND METHODS

Absolute and relative TRECs and KRECs were measured in DNA extracted from whole blood of patients with IH (n = 181, 22 of whom were reassessed after a decade of follow-up) and T1D (n = 133), AT (n = 53), and HC (n = 135) using a quantitative real-time PCR/TaqMan® probe technique.

RESULTS

Absolute and relative means of TRECs and KRECs in IH were comparable to HCs, and no differences were found between IH with and without calcium-sensing receptor antibodies or class I HLA-A*26:01 association. TRECs and KRECs did not change after a decade of follow-up. T1D had significantly higher absolute TRECs than IH, AT, and HCs, whereas AT patients showed lower TRECs and the highest KRECs; these levels showed no noteworthy correlation with thyroid dysfunctions.

CONCLUSION

Patients with IH showed TRECs and KRECs comparable to HCs, indicating an intact mechanism of T- and B-cell central immune tolerance. Interestingly, absolute TRECs were significantly higher in T1D than HCs, suggesting impaired central immune tolerance in T1D.

Autoantibodies against the calcium-sensing receptor and cytokines in autoimmune polyglandular syndromes types 2, 3 and 4

OBJECTIVE

The frequency of autoimmunity against the parathyroid glands in patients with polyglandular autoimmunity that is not due to autoimmune polyendocrine syndrome type 1 (APS1) is unclear. To investigate this, this study aimed to determine the prevalence of autoantibodies against parathyroid autoantigens, calcium-sensing receptor (CaSR) and NACHT leucine-rich-repeat protein 5 (NALP5), in a large group of patients with non-APS1 polyendocrine autoimmunity. Possible occult APS1 was investigated by cytokine autoantibody measurement and AIRE gene analysis.

DESIGN, SUBJECTS AND MEASUREMENTS

Subjects were 178 patients with APS2, 3 or 4, and 80 healthy blood donors. Autoantibodies against the CaSR, NALP5 and cytokines were measured by immunoprecipitation, radioligand binding assays or ELISA, respectively.

RESULTS

Four patient samples (2.2%), but none of the controls, were positive for CaSR autoantibodies. NALP5 autoantibodies were not detected in any participant. Eleven patients (6.2%) had cytokine autoantibodies, but none of the control samples was positive. None of the patients with cytokine autoantibodies had any known or novel mutations in the AIRE gene.

CONCLUSIONS

The low prevalence of CaSR autoantibodies indicate a very low level of subclinical parathyroid autoimmunity in APS types 2, 3 and 4. In addition, autoantibodies against cytokines constitute an uncommon feature of non-APS1 polyglandular autoimmunity.

[Not Available]

Parathormone (PTH), produced by parathyroid glands, is the main regulator of calcium homeostasis. Hypoparathyroidism (hypoPT), due to decrease of PTH production, is a rare disease. Symptoms are multiple, altering function of several organs and leading to a decrease of quality of life. Acquired etiologies, including thyroïdectomy, the main cause of hypoPT, can be distinguished from congenital etiologies, including genetic defects. HypoPT, which is classically treated by supplementation by calcium and active vitamin D, can now be treated by recombinant injection in certain indications as a poor control under classical therapy. Here are summarized current knowledge on etiologies, epidemiology, clinical manifestations and management of hypoPT.

Long-term outcome of cataract surgery in patients with idiopathic hypoparathyroidism and its relationship with their calcemic status

Cataract is a cardinal manifestation of hypoparathyroidism. Although patients with hypoparathyroidism require cataract surgery at a younger age than individuals without hypoparathyroidism, there is limited information on the outcome of this surgery. We assessed long-term complications of cataract surgery in patients with idiopathic hypoparathyroidism (IH) and its relationship with their clinical and biochemical parameters. Twenty-seven patients with IH and 25 nonhypoparathyroid controls with a minimum follow-up of 2 years after cataract surgery were assessed for visual acuity, intraocular pressure, lens centricity, Nd:YAG laser capsulotomy, and the severity of posterior capsular opacification (PCO) and anterior capsular opacification. High-resolution optical slit-lamp images were analyzed by an ophthalmologist. Patients with IH had cataract surgery at a younger age than controls (34.0 ± 16.4 years vs 58.0 ± 11.2 years, P < 0.001). A higher proportion of IH patients had dense white PCO (75.0 % vs 39.4 %, P = 0.004), Nd:YAG laser capsulotomy (44.2 % vs 10.0 %, P = 0.001), anterior capsular opacification (97.7 % vs 84.2 %, P = 0.03), and a decentric lens (28.3% vs 2.6 %, P = 0.001) at a comparable time after surgery (8.6 ± 6.1 years vs 8.7 ± 6.8 years, P = 0.85). On regression analysis, the severity of PCO in IH correlated only with male sex and not with other factors, including serum total calcium and inorganic phosphorus levels at the baseline and during follow-up. To conclude, patients with IH are likelier than individuals without IH to develop PCO and to require Nd:YAG laser capsulotomy after cataract surgery. Proper precautions should be taken during surgery to minimize this complication in IH.

Exome Sequencing Reveals Mutations in AIRE as a Cause of Isolated Hypoparathyroidism

Context

Most cases of autosomal recessive hypoparathyroidism (HYPO) are caused by loss-of-function mutations in GCM2 or PTH.

Objective

The objective of this study was to identify the underlying genetic basis for isolated HYPO in a kindred in which 3 of 10 siblings were affected.

Subjects

We studied the parents and the three adult affected subjects, each of whom was diagnosed with HYPO in the first decade of life.

Methods

We collected clinical and biochemical data and performed whole exome sequencing analysis on DNA from the three affected subjects after negative genetic testing for known causes of HYPO.

Results

Whole exome sequencing followed by Sanger sequencing revealed that all three affected subjects were compound heterozygous for two previously reported mutations, c.967_979delCTGTCCCCTCCGC:p.(L323SfsX51) and c.995+(3_5)delGAGinsTAT, in AIRE, which encodes the autoimmune regulator protein that is defective in autoimmune polyglandular syndrome type 1 (APS-1). Each parent carries one mutation, and all of the children of the patients are either heterozygous for one mutation or wild type. The affected sister developed premature ovarian failure, but the two affected brothers have no other features of APS-1 despite elevated serum levels of anti-interferon-α antibodies.

Conclusions

Our findings indicate that biallelic mutations in AIRE can cause isolated HYPO as well as syndromic APS-1. The presence of antibodies to interferon-α provides a highly sensitive indicator for loss of AIRE function and represents a useful marker for isolated HYPO due to AIRE mutations.

Pathogenic and Protective Autoantibodies in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED)

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare disorder caused by mutations in the autoimmune regulator (AIRE) gene, leading to defects in T cell selection. The disease manifestations include both autoimmune tissue destruction and immunodeficiency, with specific susceptibility to chronic mucocutaneous candidiasis. Studies have demonstrated a wide repertoire of high affinity tissue- and cytokine-specific antibodies in patients with APECED. Here, we review the antigenic targets and function of these disease-causing and disease-ameliorating antibodies.

Epidemiology and Health-Related Quality of Life in Hypoparathyroidism in Norway

OBJECTIVE

The epidemiology of hypoparathyroidism (HP) is largely unknown. We aimed to determine prevalence, etiologies, health related quality of life (HRQOL) and treatment pattern of HP.

METHODS

Patients with HP and 22q11 deletion syndrome (DiGeorge syndrome) were identified in electronic hospital registries. All identified patients were invited to participate in a survey. Among patients who responded, HRQOL was determined by Short Form 36 and Hospital Anxiety and Depression scale. Autoantibodies were measured and candidate genes (CaSR, AIRE, GATA3, and 22q11-deletion) were sequenced for classification of etiology.

RESULTS

We identified 522 patients (511 alive) and estimated overall prevalence at 102 per million divided among postsurgical HP (64 per million), nonsurgical HP (30 per million), and pseudo-HP (8 per million). Nonsurgical HP comprised autosomal dominant hypocalcemia (21%), autoimmune polyendocrine syndrome type 1 (17%), DiGeorge/22q11 deletion syndrome (15%), idiopathic HP (44%), and others (4%). Among the 283 respondents (median age, 53 years [range, 9-89], 75% females), seven formerly classified as idiopathic were reclassified after genetic and immunological analyses, whereas 26 (37% of nonsurgical HP) remained idiopathic. Most were treated with vitamin D (94%) and calcium (70%), and 10 received PTH. HP patients scored significantly worse than the normative population on Short Form 36 and Hospital Anxiety and Depression scale; patients with postsurgical scored worse than those with nonsurgical HP and pseudo-HP, especially on physical health.

CONCLUSIONS

We found higher prevalence of nonsurgical HP in Norway than reported elsewhere. Genetic testing and autoimmunity screening of idiopathic HP identified a specific cause in 21%. Further research is necessary to unravel the causes of idiopathic HP and to improve the reduced HRQOL reported by HP patients.

Prevalence of coeliac disease in idiopathic hypoparathyroidism and effect of gluten-free diet on calcaemic control

BACKGROUND

Patients with idiopathic hypoparathyroidism (IH) require variable doses of calcium and 1-α-(OH)D. The reasons for such variability are not clear. As autoimmune mechanisms may play a role in IH, there is a possibility of coexistent coeliac disease with calcium/vitamin D malabsorption.

OBJECTIVE

We assessed the prevalence of coeliac disease and antitissue transglutaminase autoantibodies (anti-tTGAbs) in IH and analysed the effect of a gluten-free diet on calcaemic control.

METHOD

A total of 171 patients with IH and 126 healthy controls were screened for anti-tTGAb. IH patients with anti-tTGAb >20 RU/ml underwent duodenoscopy and intestinal biopsy; those with biopsy-proven coeliac disease were followed up on a gluten-free diet.

RESULTS

Eleven of 171 (6·4%) patients with IH and seven of 126 (5·6%) controls had anti-tTGAb (P = 0·81). There was no difference in the clinical and biochemical parameters at diagnosis and during long-term follow-up of 7·2 ± 4·8 year (mean serum total calcium = 1·88 ± 0·16 vs 1·82 ± 0·36 mmol/l, P = 0·52; phosphorus = 1·81 ± 0·17 vs 1·87 ± 0·36 mmol/l, P = 0·53) in IH patients with and without anti-tTGAb. Although CaSRAb positivity was comparable in the two groups, IH patients with anti-tTGAb had higher TPOAb positivity (45·5% vs 12·8%, P = 0·02). Coeliac disease was diagnosed in only 2/9 patients with IH on biopsy, both of whom showed improved calcaemic control with a gluten-free diet.

CONCLUSION

The prevalence of coeliac autoimmunity (6·4%) and coeliac disease (1·2%) in patients with IH seems to be similar to that in the general population. Notwithstanding this modest prevalence, it is important to be aware of the potential occurrence of coeliac disease with IH and the beneficial effect of a gluten-free diet on calcium control.

Calcium-sensing receptor sequencing in 21 patients with idiopathic or familial parathyroid disorder: pitfalls and characterization of a novel I32 V loss-of-function mutation

The calcium-sensing receptor (CaSR) is a G-protein-coupled receptor with a crucial role in calcium homeostasis. Mutations in the CaSR gene may lead to specific parathyroid disorders due to either gain-of-function (autosomal dominant hypercalciuric hypocalcemia; ADHH) or loss-of-function (familial hypocalciuric hypercalcemia; FHH). Our aim was to evaluate CaSR mutations as a cause of disease in selected patients. We identified and recruited patients with phenotypes suggestive of CaSR-related parathyroid disorders. DNA was extracted, and CaSR gene was sequenced. Live-ratiometric measurements of intracellular [Ca(2+)] and Western blot assays for evaluation of MAPK phosphorylation in response to changes in extracellular [Ca(2+)] were performed in transiently transfected HEK-293T cells to functionally characterize mutants. A total of 21 patients were evaluated, seven of them with idiopathic hypoparathyroidism (suspected ADHH) and 14 with hyperparathyroidism (suspected FHH). In the latter group two patients were found to harbor missense mutations: a novel heterozygous I32 V mutation in a female index case and a sporadic known R185Q mutation in a 1-year-old girl. In-vitro functional studies showed that I32 V is an inactivating mutation. In our study, most patients had normal CaSR sequencing. This suggests that phenotypic pitfalls may occur at time of patients' selection for CaSR sequencing. In one patient with strong positive pre-test probability based on both familial history and appropriate phenotype, a novel I32 V mutation leading to FHH was identified and characterized. In cases of familial parathyroid disorders, CaSR sequencing should be performed, but if negative, one should consider involvement of alternative genes or mechanisms.

Hypoparathyroidism and central diabetes insipidus: in search of the link

Two siblings (a 15-year-old boy and an 11-year-old girl) who presented with hypocalcemic seizure at the age of 2 years and 2 months (boy) and 2 years and 4 months (girl) were diagnosed with hypoparathyroidism. At the age of 3 years, the girl developed central diabetes insipidus with good response to desmopressin acetate treatment. The family history was unremarkable, and there was no consanguinity between the parents. The father is of Iraqi/Egyptian Jewish origin and the mother is of Iranian/Romanian Jewish origin. Sequence analysis of the candidate genes for isolated hypoparathyroidism encoding calcium-sensing receptor, parathyroid hormone, and glial cells missing homolog B did not reveal any mutations. Whole-exome sequencing identified a homozygous mutation in the autoimmune regulatory gene (AIRE), c.374A>G;p.Y85C, characteristic for Jewish Iranians with autoimmune polyendocrine syndrome type 1 (APS1), which was confirmed by the Sanger sequencing. Antibodies against the adrenal, pancreatic islet cell, ovary, thyroid, pituitary, celiac, and parietal cell were negative in both siblings, while anti-diuretic hormone antibodies were positive only in the girl. No other symptoms or signs of APS1 developed during all the years of follow-up.

CONCLUSION

APS1 should be part of the differential diagnosis in children presenting with isolated hypoparathyroidism or hypoparathyroidism with central diabetes insipidus (CDI). These cases show that the AIRE mutation characteristic of Iranian Jews can also be found in non-Iranian Jews.

Menstruation associated hypocalcemic symptoms and serum calcium in patients with idiopathic hypoparathyroidism

BACKGROUND

Some of the patients with idiopathic hypoparathyroidism (IHP) report symptoms of hypocalcemia during menstruation. There is limited data on this observation.

METHODS

Twenty six menstruating women with IHP and 26 healthy controls were questioned regarding symptoms suggestive of hypocalcemia during menstruation. Twelve patients and eight controls were asked to prospectively monitor symptoms suggestive of hypocalcemia and premenstrual syndrome (PMS) if any, over two consecutive menstrual cycles. Serum ionized calcium (SiCa++), total and albumin adjusted calcium and intact paratharmone (iPTH) were measured at eight points covering menstrual, immediate post-menstrual, mid-cycle and premenstrual phase.

RESULTS

Twelve of the 26 (46.2%) patients with IHP reported hypocalcemic symptoms during menstruation as compared to none of the controls. During prospective monitoring, there was no specific trend of hypocalcemic symptoms with respect to the phase of menstrual cycle. The mean SiCa++, serum total and albumin-adjusted calcium, iPTH and inorganic-phosphorus measured over two menstrual cycles were not significantly different in either of the two study groups. None of the subjects had PMS.

CONCLUSION

Women with IHP do not show any trend of hypocalcemic symptoms or fluctuations in serum calcium over different phases of menstrual cycles. Therefore, patients with hypoparathyroidism linking hypocalcemic symptoms with menstruation should be reassured regarding lack of this association.

Prevalence and clinical associations of calcium-sensing receptor and NALP5 autoantibodies in Finnish APECED patients

CONTEXT

Previous studies have identified the calcium-sensing receptor (CaSR) and NALP5 as parathyroid autoantibody targets in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). However, although NALP5 antibodies have been associated with the occurrence of hypoparathyroidism (HP) in APECED, it is unclear whether CaSR antibodies are a specific or sensitive marker for APECED-associated HP.

OBJECTIVE

The objective of the study was to identify associations between the presence of CaSR and NALP5 antibodies and the disease manifestations and demographic characteristics of Finnish APECED patients.

DESIGN, SUBJECTS, AND METHODS

This was a case-control study including 44 APECED patients and 38 age- and sex-matched healthy controls. Antibodies against the CaSR and NALP5 were detected using immunoprecipitation assays and radioligand binding assays, respectively.

RESULTS

CaSR and NALP5 antibodies were detected in 16 of 44 (36%) and 13 of 44 (30%) patients, respectively. No statistically significant associations were found between the presence of CaSR or NALP5 antibodies and the disease manifestations of APECED including HP (P > .05). For the diagnosis of HP, CaSR and NALP5 antibodies had specificities of 83% and 50%, respectively, and sensitivities of 39% and 26%, respectively. A significant association between both a shorter APECED and HP duration (<10 y) and positivity for CaSR antibodies was noted (P = .019 and P = .0061, respectively).

CONCLUSION

Neither CaSR nor NALP5 antibodies were found to be specific or sensitive markers for HP in APECED. Further investigations are required to determine the exact role of the autoimmune response against the CaSR and NALP5 in the pathogenesis of this autoimmune syndrome.

Diagnosis and classification of autoimmune parathyroid disease

Hypoparathyroidism (HP) is clinically characterized by the presence of hypocalcemia, usually associated with specific signs and symptoms that depend on how severe and chronic the disease becomes. HP is usually caused by surgical removal of all four parathyroids, while other forms are rarer. Autoimmune HP can occur as an isolated disease or as part of an autoimmune polyendocrine syndrome. Here we review what is known about parathyroid gland autoimmunity, focusing on recently-proposed parathyroid autoantibody markers, and particularly those directed against NACHT leucine-rich-repeat protein 5 and calcium-sensing receptor. We also describe the clinical characteristics of HP and design a diagnostic algorithm for autoimmune HP.

Calcium-sensing receptor autoantibodies and idiopathic hypoparathyroidism

CONTEXT

Data on calcium-sensing receptor autoantibodies (CaSRAbs) in hypoparathyroidism are variable.

OBJECTIVE

We assessed the prevalence and significance of CaSRAbs in idiopathic hypoparathyroidism.

DESIGN

This was a case-control study.

SUBJECTS

One hundred forty-seven patients with idiopathic hypoparathyroidism treated during 1998-2011 in a tertiary care setting and 348 controls [healthy, n = 199; type 1 diabetes mellitus (T1DM), n = 99; and chronic lymphocytic thyroiditis (CLT), n = 50] participated in the study.

METHODS

CaSRAb assays included Western blot with CaSR protein expressed in Escherichia coli or human embryonic kidney (HEK)-293 cells, immunoprecipitation (IP) using in vitro-transcribed/translated protein, and indirect immunofluorescence on HEK293-CaSR. Functional significance was assessed by ERK1/2 phosphorylation. PTH and CaSR genes were sequenced for mutations.

RESULTS

E coli-Western blot assay revealed 16.3% CaSRAb positivity in idiopathic hypoparathyroidism, which was comparable with healthy subjects and CLT but significantly less than the T1DM controls. The prevalence of CaSRAbs on HEK293-Western blot (24.5%) against 150 kDa and/or 168 kDa protein in hypoparathyroidism was significantly higher than the healthy subjects, T1DM, and CLT. IP assay showed CaSRAbs in 12.9% of the hypoparathyroid patients but not in controls. The sensitivity and specificity of CaSRAbs in E coli and HEK-293-CaSR Western blot and IP assays were 16.3% and 83.1%, 24.5% and 88.9%, and 12.9% and 100%, respectively, and 42.1% of the cases detected were common in the IP assay and HEK293-Western blot. Duration of illness and coexistent autoimmunity were similar in patients with and without CaSRAbs. The CaSRAb-positive sera showed no immunofluorescence and phosphorylated ERK1/2 activity. The CaSR gene sequence was normal in all patients. One of the patients showed a novel p.Met1_Asp6del mutation in the signal peptide region of the PTH gene.

CONCLUSION

IP performed the best in detecting CaSRAbs in 12.9% of hypoparathyroid patients. Although CaSRAbs were functionally inert, its clinical relevance remains due to 100% specificity. Limited prevalence of CaSRAb suggests heterogeneity in the etiology of idiopathic hypoparathyroidism or the presence of CaSR epitopes other than those measured in the current study.

Neuropsychological dysfunction in idiopathic hypoparathyroidism and its relationship with intracranial calcification and serum total calcium

BACKGROUND

There is limited information on neuropsychological and neurological dysfunctions in patients with idiopathic hypoparathyroidism (IH).

OBJECTIVE

To assess neuropsychological and neurological dysfunctions in IH and its associated factors in a cross-sectional design.

METHOD

Neuropsychological functions were assessed in 62 patients with IH and 70 controls using a battery of cognitive tests. Neurological assessment included extrapyramidal and cerebellar signs. Assessment of intracranial calcification and volume of basal ganglia calcification (BGC) were made on computed tomography and of calcium control by averaging serum total calcium values available during the follow-up.

RESULTS

A significantly higher proportion of patients with IH showed neuropsychological dysfunctions than controls (32.3 (95% CI: 20.9-45.3) vs 5.7% (95% CI: 1.6-14.0), P<0.001). Neurological signs were present in 35.5% patients (extrapyramidal: 16.1%; cerebellar: 20.9%). Volume of BGC and number of sites with intracranial calcifications including cerebellum/dentate were comparable in patients with and without neuropsychological, extrapyramidal or cerebellar dysfunctions. Cognitive dysfunction score was lower by 1.7 points in males than in females (P=0.02) and increased by 0.21 and 5.5 for each year increase in the duration of illness (P=0.001) and one unit increase in serum calcium-phosphorus product (P=0.01) respectively. The scores improved by 0.27 for every mg% increase in serum calcium (P=0.001).

CONCLUSION

Neuropsychological dysfunctions are present in up to one-third of patients with IH and correlate with duration of illness, female gender, serum calcium and calcium-phosphorus product during follow-up but not with intracranial calcification. These dysfunctions may affect their daily functions, safety and drug compliance.

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy: insights into genotype-phenotype correlation

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare autosomal recessive disease, caused by mutations of a single gene named autoimmune regulator gene (AIRE) which results in a failure of T cell tolerance within the thymus. Chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease are the hallmarks of the syndrome. APECED is also characterized by several autoimmune endocrine and nonendocrine manifestations, and the phenotype is often complex. Moreover, even though APECED is a monogenic disease, its clinical picture is generally dominated by a wide heterogeneity both in the severity and in the number of components even among siblings with the same AIRE genotype. The variability of its clinical expression implies that diagnosis can be challenging, and a considerable delay often occurs between the appearance of symptoms and the diagnosis. Since a prompt diagnosis is essential to prevent severe complications, clinicians should be aware of all symptoms and signs of suspicion. The aim of this paper is to give an overview on the clinical presentation and diagnostic criteria of APECED and to focus on current knowledge on genotype-phenotype correlation.