Prevalence of idiopathic hypoparathyroidism and pseudohypoparathyroidism in Japan

Diverse genetic aetiologies and clinical outcomes of paediatric hypoparathyroidism

CONTEXT

Hypoparathyroidism is characterized by hypocalcaemia, hyperphosphataemia, and low or inappropriately normal parathyroid hormone (PTH) levels. Idiopathic or genetic drivers are the predominant causes of hypoparathyroidism in paediatric-age patients.

OBJECTIVE

This study investigated the aetiology and clinical course of primary hypoparathyroidism in infancy and childhood.

SUBJECTS AND MEASUREMENTS

This study included 37 patients (23 males, 14 females) with primary hypoparathyroidism diagnosed prior to 18 years of age. We analysed aetiologies, initial presentation, age at diagnosis, endocrine and radiological findings, and outcomes.

RESULTS

The median age at presentation was 1·7 months (range 1 day-17 years), and the mean follow-up duration was 7·0 ± 5·3 years (range 0·5-16·8 years). Our cohort included 22 cases (59·5%) of 22q11·2 microdeletion syndrome. Other aetiologies included hypoparathyroidism-deafness-renal dysplasia syndrome (5/37, 13·5%) and one patient each with autoimmune polyglandular syndrome type 1, Kearns-Sayre syndrome and Kenny-Caffey syndrome. The remaining 7 (18·9%) patients were classified as idiopathic hypoparathyroidism cases. Among the 15 patients who underwent brain imaging, 5 (33·3%) had basal ganglia calcification. Among the 26 patients examined by renal imaging, 5 (19·2%) had either nephrocalcinosis or a renal stone. After 11 months of calcium or calcitriol supplementation, 16 patients (43·2%) discontinued medication. The final PTH levels were significantly higher in patients with transient hypoparathyroidism than those with permanent hypoparathyroidism.

CONCLUSIONS

Identification of the genetic aetiologies of hypoparathyroidism makes it possible to predict patient outcomes and provide appropriate genetic counselling. Long-term treatment with calcium and calcitriol necessitates monitoring for renal complications.

Abnormal Methylation Status of the GNAS Exon 1A Region in Pseudohypohyperparathyroidism Combined With Turner Syndrome

Pseudohypohyperparathyroidism (PHHP) is a rare type of pseudohypoparathyroidism (PHP), which seems to have a normal skeletal response to parathyroid hormone but shows renal resistance. Almost all patients with PHHP have PHP Ib, a subtype of PHP that is usually caused by GNAS methylation defects, often in exon 1A. Some features of Albright hereditary osteodystrophy can occasionally be found in patients with PHHP, but these features are also common in Turner syndrome. The authors report on an extremely rare case of a patient with PHHP and Turner syndrome, a 47-year-old woman who sought medical attention for hypocalcemia and elevated parathyroid hormone. She had no family history of hypocalcemia and no STX16 gene deletions. She had a mosaic karyotype of 46, X, del(X)(p11.4)/45, XO. Pyrosequencing was performed to determine the GNAS exon 1A methylation. The degree of methylation found in exon 1A of the patient was lower than her unaffected relatives.

The Epidemiology of Nonsurgical Hypoparathyroidism in Denmark: A Nationwide Case Finding Study

Nonsurgical hypoparathyroidism (HypoPT) is a rare disorder most often caused by mutations in different genes. It is characterized by hypocalcaemia with inappropriately low PTH levels. Knowledge about this group of patients, including their mortality and morbidity, is very sparse. The aim was to identify all patients diagnosed with nonsurgical HypoPT in Denmark and assess their mortality and risk of complications. Through registers and review of individual patient hospital charts we identified all patients diagnosed with nonsurgical HypoPT in Denmark between 1977 and 2012. We assessed their mortality and morbidity by comparing them with a group of age- and gender-matched population-based controls. We identified a total of 180 patients with nonsurgical HypoPT among whom 123 (68%) were alive at the date of follow-up (prevalence of 2.3/100,000 inhabitants). Compared with controls, mortality was not increased, but patients had a significantly increased risk of renal insufficiency (hazard ratio [HR] 6.01), cardiovascular diseases (HR 1.91), neuropsychiatric complications (HR 2.45), infections (HR 1.94), seizures (HR 10.05), cataract (HR 4.21), and fractures at the upper extremities (HR 1.93). In contrast patients had significantly reduced risk of malignant diseases (HR 0.44). In conclusion, nonsurgical HypoPT is a rare disease associated with a number of complications that should be considered when taking care of these patients.

[Short bowel syndrome in Germany. Estimated prevalence and standard of care]

OBJECTIVE

As data about prevalence and standard of care in short bowel syndrome (SBS) are not available for Germany, this study estimated the prevalence and assessed the medical infrastructure to potentially improve care of SBS patients.

METHODS

In a validated approach for prevalence estimation in rare diseases, a randomized census of 478 size-stratified hospitals with surgical, internal medicine and pediatric departments was conducted to estimate SBS prevalence. The number of SBS patients, specialized outpatient clinics and caregiver expertise were assessed.

RESULTS

The response rate was 85 % of randomized hospitals (405/478). Strata-derived estimation yielded a total of 2,808 SBS patients in Germany for 2011/2012 (95 % CI: 1750.3865), translating into a prevalence estimation for 34/million inhabitants (95 % CI: 21.47). Overall expertise in SBS treatment was only rated "satisfactory" by most caregivers. While 86 specialized outpatient clinics were identified, there was no central registry to access these resources.

CONCLUSION

Short bowel syndrome, with a newly estimated prevalence of 34/million inhabitants is not a very rare medical condition in Germany. The interdisciplinary approach needed for optimal care for SBS patients would be greatly facilitated by a central registry.

Mutations in HADHB, which encodes the β-subunit of mitochondrial trifunctional protein, cause infantile onset hypoparathyroidism and peripheral polyneuropathy

Mitochondrial trifunctional protein (MTP) is a hetero-octamer composed of four α- and four β-subunits that catalyzes the final three steps of mitochondrial β-oxidation of long chain fatty acids. HADHA and HADHB encode the α-subunit and the β-subunit of MTP, respectively. To date, only two cases with MTP deficiency have been reported to be associated with hypoparathyroidism and peripheral polyneuropathy. Here, we report on two siblings with autosomal recessive infantile onset hypoparathyroidism, peripheral polyneuropathy, and rhabdomyolysis. Sequence analysis of HADHA and HADHB in both siblings shows that they were homozygous for a mutation in exon 14 of HADHB (c.1175C>T, [p.A392V]) and the parents were heterozygous for the mutation. Biochemical analysis revealed that the patients had MTP deficiency. Structural analysis indicated that the A392V mutation identified in this study and the N389D mutation previously reported to be associated with hypoparathyroidism are both located near the active site of MTP and affect the conformation of the β-subunit. Thus, the present patients are the second and third cases of MTP deficiency associated with missense HADHB mutation and infantile onset hypoparathyroidism. Since MTP deficiency is a treatable disease, MTP deficiency should be considered when patients have hypoparathyroidism as the initial presenting feature in infancy.

Mutations in pseudohypoparathyroidism 1a and pseudopseudohypoparathyroidism in ethnic Chinese

An inactivating mutation in the GNAS gene causes either pseudohypoparathyroidism 1a (PHP1A) when it is maternally inherited or pseudopseudohypoparathyroidism (PPHP) when it is paternally inherited. We investigated clinical manifestations and mutations of the GNAS gene in ethnic Chinese patients with PHP1A or PPHP. Seven patients from 5 families including 4 girls and 2 boys with PHP1A and 1 girl with PPHP were studied. All PHP1A patients had mental retardation. They were treated with calcitriol and CaCO3 with regular monitoring of serum Ca levels, urinary Ca/Cr ratios, and renal sonography. Among them, 5 patients also had primary hypothyroidism suggesting TSH resistance. One female patient had a renal stone which was treated with extracorporeal shockwave lithotripsy. She had an increased urinary Ca/Cr ratio of 0.481 mg/mg when the stone was detected. We detected mutations using PCR and sequencing as well as analysed a splice acceptor site mutation using RT-PCR, sequencing, and minigene construct. We detected 5 mutations: c.85C>T (Q29*), c.103C>T (Q35*), c.840-2A>G (R280Sfs*21), c.1027_1028delGA (D343*), and c.1174G>A (E392K). Mutations c.840-2A>G and c.1027_1028delGA were novel. The c.840-2A>G mutation at the splice acceptor site of intron 10 caused retention of intron 10 in the minigene construct but skipping of exon 11 in the peripheral blood cells. The latter was the most probable mechanism which caused a frameshift, changing Arg to Ser at residue 280 and invoking a premature termination of translation at codon 300 (R280Sfs*21). Five GNAS mutations in ethnic Chinese with PHP1A and PPHP were reported. Two of them were novel. Mutation c.840-2A>G destroyed a spice acceptor site and caused exon skipping. Regular monitoring and adjustment in therapy are mandatory to achieve optimal therapeutic effects and avoid nephrolithiasis in patients with PHP1A.

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.

Primary immunodeficiency in Japan; epidemiology, diagnosis, and pathogenesis

Primary immunodeficiency (PID) constitutes a large group of diseases, including almost 180 hereditary disorders. The patients show susceptibility to various infections due to congenital defects of the immune system. It is also known that PID patients suffer from non-infectious complications, including autoimmune diseases and malignant disorders. During the last 20 years the number of known PID has increased considerably. New PID conferring a specific predisposition to infections with one or a few pathogens have been described. Disorders of innate immunity and various autoinflammatory disorders were included in new categories. In contrast, the incidence, clinical manifestations, and genetic factors of PID seem to be different among countries or races. The clinical manifestations can differ depending on the hygiene conditions, health-care environment, and vaccination policy, and so on. A nationwide survey on PID patients in Japan provided a lot of information regarding these issues, and it uncovered a previously unknown complication of PID, endocrine disorders. In this review, the data concerning epidemiology and clinical characteristics of PID in Japan obtained in the nationwide questionnaire survey, and the results of studies on the clinical and genetic characteristics of Japanese patients with Mendelian susceptibility to mycobacterial disease and interleukin-1 receptor-associated kinase 4 deficiency are presented in the light of their pathogenesis and pathophysiology.

Genetic and clinical characteristics of korean patients with isolated hypoparathyroidism: from the Korean hypopara registry study

Isolated hypoparathyroidism (IH) shows heterogeneous phenotypes and can be caused by defects in a variety of genes. The goal of our study was to determine the clinical features and to analyze gene mutations in a large cohort of Korean patients with sporadic or familial IH. We recruited 23 patients. They showed a broad range of onset age and various values of biochemical data. Whole exome sequencing was performed on two affected cases and one unaffected individual in a family. All coding exons and exon-intron borders of GCMB, CASR, and prepro-PTH were sequenced using PCR-amplified DNA. In one family who underwent the whole exome sequencing analysis, approximately 300 single nucleotide changes emerged as candidates for genetic alteration. Among them, we identified a functional mutation in exon 2 of GCMB (C106R) in two affected cases. Besides, heterozygous gain-of-function mutations in the CASR gene were found in other subjects; D410E and P221L. We also found one single nucleotide polymorphism (SNP) in the prepro-PTH gene, five SNPs in the CASR gene, and four SNPs in the GCMB gene. The current study represents a variety of biochemical phenotypes in IH patients with the molecular genetic diagnosis of IH.

Epidemiology and clinical experience of chronic intestinal pseudo-obstruction in Japan: a nationwide epidemiologic survey

Background

We estimated the prevalence and incidence of chronic intestinal pseudo-obstruction (CIPO) in Japan, investigated the patterns of hospital visits among those with CIPO, and examined present knowledge of CIPO among medical professionals.

Methods

A self-administered questionnaire survey was distributed to targeted hospitals throughout Japan, which were selected using stratified random sampling. The questionnaire asked about the number of patients receiving treatment for CIPO, the frequency of their hospital visits, and overall clinical knowledge of CIPO among medical professionals.

Results

CIPO prevalence was estimated to be 1.00 and 0.80 cases per 100 000 males and females, respectively. Incidence was 0.21 and 0.24 cases per 100 000 males and females, respectively. Prevalence and incidence did not significantly differ males and females. Mean age of patients was 63.1 years for males and 59.2 for females. Accurate diagnosis of CIPO sometimes required more than 3 months after initial presentation. Most medical professionals were unaware of or poorly understood CIPO.

Conclusions

We estimated the prevalence and incidence of CIPO in Japan, using data from a nationwide survey. The findings suggest that knowledge of CIPO should be further disseminated so that the disease is not overlooked and is diagnosed without delay.

Pseudohypoparathyroidism: a rare but important cause of hypocalcaemia

We present a 46-year-old Caucasian lady with symptomatic hypocalcaemia. Investigations revealed markedly raised parathyroid hormone (PTH) levels with vitamin D deficiency. A number of conditions causing secondary hyperparathyroidism were ruled out from her medical history and initial investigations. The main differential diagnoses were vitamin D deficiency and PTH resistance (pseudohypoparathyroidism, PHP). With high-normal serum phosphate and normal alkaline phosphatase, and a lack of symptoms associated with osteomalacia, vitamin D deficiency alone was unlikely to be the cause of hypocalcaemia. Given a normal physical appearance, genetic testing was arranged and confirmed the diagnosis of PHP type Ib. She is currently taking activated vitamin D to maintain calcium homeostasis. PTH resistance is the hallmark of PHP, a rare complex genetic disorder, which can be easily missed resulting in potentially serious consequences.

Prognostic factors in patients with idiopathic portal hypertension: Two Japanese nationwide epidemiological surveys in 1999 and 2005

AIM

  To investigate factors affecting disease prognosis among patients with idiopathic portal hypertension (IPH).

METHODS

  Two Japanese nationwide epidemiological surveys on IPH were conducted in 1999 and 2005. Analyzing data from each cross-sectional survey separately, we examined the consistent prognostic factors detected from each analysis and assessed the effect of treatments for varices on IPH prognosis. Outcome was the disease condition at last observation compared with that at diagnosis, categorized into two levels (recovered/improved and unchanged/aggravated/deceased). To evaluate the association with each characteristic, we calculated adjusted odds ratio (OR) and 95% confidence interval (CI) using a binary model for logistic regression.

RESULTS

  Among 160 patients with IPH in 1999 and 85 in 2005, 10% had aggravated disease at a mean of 6-7 years after the diagnosis. Statistically significant ORs were observed for two factors: esophageal varices, especially of F(2-3) stage, at diagnosis (OR = 6.83, 95% CI = 2.10-22.1 in 1999; OR = 10.7, 95% CI = 1.08-105 in 2005) ameliorated IPH; and hepatic encephalopathy at diagnosis (OR = 0.19, 95% CI = 0.03-1.04 in 1999; crude OR = 0.05, 95% CI = 0.01-0.60 in 2005 using a proportional odds model) worsened IPH. Further analyses explained that the apparent ameliorating effect of esophageal varices was due to the effect of subsequent treatment (OR = 4.59, 95% CI = 0.89-23.7 in 2005).

CONCLUSION

  The prognosis of IPH would be better if varices were adequately controlled. Patients with liver failure at diagnosis would be at high risk for subsequent disease aggravation.

Endocrine complications in primary immunodeficiency diseases in Japan

BACKGROUND

In spite of the accumulating evidence on the interaction between the immune and endocrine systems based on the recent progress in molecular genetics, there have been few epidemiological studies focused on the endocrine complications associated with primary immunodeficiency diseases (PID).

OBJECTIVE

To investigate the prevalence and clinical features of endocrine complications in patients with PID in a large-scale study.

DESIGN AND PARTICIPANTS

This survey was conducted on patients with PID who were alive on 1 December 2008 and those who were newly diagnosed and died between 1 December 2007 and 30 November 2008 in Japan. We investigated the prevalence and the clinical data of the endocrine complications in 923 patients with PID registered in the secondary survey.

RESULTS

Among 923 PID patients, 49 (5·3%) had endocrine disorders. The prevalence of the endocrine diseases was much higher in patients with PID than in the general population in the young age group, even after excluding patients with immune dysregulation.

CONCLUSIONS

Endocrine disorders are important complications of PID. Analysis of the endocrine manifestations in patients with PID in a large-scale study may provide further insights into the relationship between the immune and endocrine systems.

Presence of strong association of the major histocompatibility complex (MHC) class I allele HLA-A*26:01 with idiopathic hypoparathyroidism

CONTEXT

The pathogenesis of isolated hypoparathyroidism, also referred to as idiopathic hypoparathyroidism (IH), is not clear. There is a paucity of information related to the immunogenetic basis of the disease due to its rarity. A recurrent theme of several autoimmune disorders is aberrant antigen presentation.

OBJECTIVE

We investigated for the association of alleles of the human leukocyte antigen (HLA) class I and II loci with IH.

PATIENTS AND CONTROLS

A total of 134 patients with IH and 902 healthy controls from the same ethnic background participated in the study.

RESULTS

There was a significant increase of HLA class I alleles HLA-A*26:01 [P < 1.71 × 10(-34); odds ratio (OR) = 9.29; 95% confidence interval (CI) = 6.08-14.16] and HLA-B*08:01 (P < 8.19 × 10(-6); OR = 2.59; 95% CI = 1.63-4.04) in patients with IH compared to healthy controls. However, the association of A*26:01 was primary because B*08:01 was in linkage disequilibrium with A*26:01. Although the major histocompatibility complex (MHC) is very polymorphic, several alleles of HLA loci share key residues at anchor positions in the peptide binding pockets such that similar peptides may be presented by different MHC molecules encoded by the same locus. These allelic forms with similar anchoring amino acids have been clustered in supertypes. An analysis of HLA-A locus supertypes A01, A02, A03, and A04 revealed that supertype A01 was significantly increased (P < 9.18 × 10(-9); OR = 2.95) in IH compared to controls. However, this increase in the supertype A01 was contributed by A*26:01 because 68.7% of the A01 samples had A*26:01. Other alleles of the supertype did not show any significant differences.

CONCLUSION

The strong association of HLA-A*26:01 suggests an important role of MHC class I-mediated presentation of autoantigenic peptides to CD8(+) cytotoxic T cells in the pathogenesis of IH. These data provide evidence for the autoimmune etiology of IH akin to other autoimmune disorders like type 1 diabetes and rheumatoid arthritis.

Pseudohypoparathyroidism type Ia manifesting as intractable epilepsy in a 23-year-old female

Pseudohypoparathyroidism is a rare disorder of calcium metabolism that involves target organ resistance to the action of the parathyroid hormone. As a result, calcium levels may become dangerously low, sometimes leading to seizures and other symptoms. We present a case of a 23-year-old Somalian female on antiepileptic therapy presenting with intractable epilepsy. She was subsequently found to have pseudohypoparathyroidism type Ia. She had multiple reasons accounting for loss of seizure control, including worsening hypocalcemia from resistance to the parathyroid hormone; vitamin D deficiency, which could have resulted from lack of exposure to direct sunlight and her antiepileptic medication; and extensive calcium deposition in the brain due to pseudohypoparathyroidism. The patient was stabilized with intravenous therapy and oral calcium, vitamin D, and calcitriol. Her antiepileptic therapy was changed to a medication that did not interfere with vitamin D metabolism or contribute to worsening hypocalcemia.

Diagnostic criteria, clinical features, and incidence of thyroid storm based on nationwide surveys

BACKGROUND

Thyroid storm (TS) is life threatening. Its incidence is poorly defined, few series are available, and population-based diagnostic criteria have not been established. We surveyed TS in Japan, defined its characteristics, and formulated diagnostic criteria, FINAL-CRITERIA1 and FINAL-CRITERIA2, for two grades of TS, TS1, and TS2 respectively.

METHODS

We first developed diagnostic criteria based on 99 patients in the literature and 7 of our patients (LIT-CRITERIA1 for TS1 and LIT-CRITERIA2 for TS2). Thyrotoxicosis was a prerequisite for TS1 and TS2 as well as for combinations of the central nervous system manifestations, fever, tachycardia, congestive heart failure (CHF), and gastrointestinal (GI)/hepatic disturbances. We then conducted initial and follow-up surveys from 2004 through 2008, targeting all hospitals in Japan, with an eight-layered random extraction selection process to obtain and verify information on patients who met LIT-CRITERIA1 and LIT-CRITERIA2.

RESULTS

We identified 282 patients with TS1 and 74 patients with TS2. Based on these data and information from the Ministry of Health, Labor, and Welfare of Japan, we estimated the incidence of TS in hospitalized patients in Japan to be 0.20 per 100,000 per year. Serum-free thyroxine and free triiodothyroine concentrations were similar among patients with TS in the literature, Japanese patients with TS1 or TS2, and a group of patients with thyrotoxicosis without TS (Tox-NoTS). The mortality rate was 11.0% in TS1, 9.5% in TS2, and 0% in Tox-NoTS patients. Multiple organ failure was the most common cause of death in TS1 and TS2, followed by CHF, respiratory failure, arrhythmia, disseminated intravascular coagulation, GI perforation, hypoxic brain syndrome, and sepsis. Glasgow Coma Scale results and blood urea nitrogen (BUN) were associated with irreversible damages in 22 survivors. The only change in our final diagnostic criteria for TS as compared with our initial criteria related to serum bilirubin concentration >3 mg/dL.

CONCLUSIONS

TS is still a life-threatening disorder with more than 10% mortality in Japan. We present newly formulated diagnostic criteria for TS and clarify its clinical features, prognosis, and incidence based on nationwide surveys in Japan. This information will help diagnose TS and in understanding the factors contributing to mortality and irreversible complications.

Elevated muscle enzymes and muscle biopsy in idiopathic hypoparathyroidism patients

OBJECTIVE

To study idiopathic hypoparathyroidism (IHP) myopathy and its pathogenesis by histology method.

METHODS

We retrospectively analyzed the clinical data of nine IHP patients during the years 2006-2010.

RESULTS

We found that: 1) there was an inverse relationship between the decreased serum calcium level and the elevated muscle enzymes level; 2) the IHP patients had mild-to-moderate muscle cells vacuolar degeneration and focal hyaline degeneration by hematoxylin-eosin (HE) staining; 3) except for 2 patients, the others' muscles striations were undetectable by phosphotungstic acid hematoxylin staining; 4) 2 patients with extremely high level of creatine kinase and relatively longer disease duration had muscle atrophy, multiple focal muscle fiber hyaline degeneration and sarcolemma cells hyperplasia by HE staining; 5) all patients had different degree of immune complex deposition along the muscle cell membranes by immunofluorescence staining.

CONCLUSION

The patients with IHP had some histological changes in skeletal muscles but with no specificity. The changes in muscles and the elevated serum muscle enzymes were related to hypocalcemia. The severity of changes in muscles was related to the duration of hypocalcemia and not only to its degree.

Intracranial hemorrhage revealing pseudohypoparathyroidism as a cause of fahr syndrome

Pseudohypoparathyroidism is an infrequently encountered disease. It is one of the causes of Fahr syndrome which also is a rare clinical entity caused by multiple diseases. A 4-year-old man hospitalized for sudden onset left hemiparesis and hypertension was diagnosed to have right thalamic and midbrain hemorrhage on plain CT scan of the head which also revealed co-existent extensive intracranial calcifications involving the basal ganglia and cerebellum bilaterally. General physical examination revealed features of Albright hereditary osteodystrophy, goitre, hypertension, left hemiparesis, and signs of cerebellar dysfunction. Laboratory findings suggested hypocalcemia, hyperphosphatemia along with high TSH, low FT₄, low FT₃, and high anti-TPO antibody. Though bilateral intracranial calcifications are usually encountered as an incidental radiological finding in the CT scan of brain, in this case, the patient admitted for thalamic and midbrain hemorrhage was on investigation for associated intracranial calcification, and goitre was also found to have coexisting pseudohypoparathyroidism and autoimmune hypothyroidism.

Nationwide survey of patients with primary immunodeficiency diseases in Japan

To determine the prevalence and clinical characteristics of patients with in Japan, we conducted a nationwide survey of primary immunodeficiency disease (PID) patients for the first time in 30 years. Questionnaires were sent to 1,224 pediatric departments and 1,670 internal medicine departments of Japanese hospitals. A total of 1,240 patients were registered. The estimated number of patients with PID was 2,900 with a prevalence of 2.3 per 100,000 people and homogenous regional distribution in Japan. The male-to-female ratio was 2.3:1 with a median age of 12.8 years. Adolescents or adults constituted 42.8% of the patients. A number of 25 (2.7%) and 78 (8.5%) patients developed malignant disorders and immune-related diseases, respectively, as complications of primary immunodeficiency disease. Close monitoring and appropriate management for these complications in addition to prevention of infectious diseases is important for improving the quality of life of PID patients.

Clinical characterization and identification of two novel mutations of the GNAS gene in patients with pseudohypoparathyroidism and pseudopseudohypoparathyroidism

OBJECTIVE

Pseudohypoparathyroidism (PHP) and pseudopseudohypoparathyroidism (PPHP) are rare disorders resulting from genetic and epigenetic aberrations in the GNAS locus.

DESIGN

Investigation of clinical characteristics and molecular analysis in PHP and PPHP.

PATIENTS

Fourteen subjects from 13 unrelated families including subjects with PPHP (n = 1), PHP-Ia (n = 6) and PHP-Ib (n = 7) were enrolled.

MEASUREMENTS

Clinical data, including age at presentation, presenting symptom, auxological findings, family history, presence of Albright hereditary osteodystrophy (AHO) features and hormonal and biochemical findings, were analysed. The GNAS locus was subjected to direct sequencing and methylation analysis using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA).

RESULTS

Of the 13 PHP subjects, 10 (three PHP-Ia and seven PHP-Ib) presented with hypocalcemic tetany at ages ranging from 7 to 14·8 years. Subcutaneous calcification was observed as an early manifestation of AHO in one PHP-Ia patient (age, 2·9 years) and one PPHP patient (age, 7 months). Six PHP-Ia and one PPHP harboured four different heterozygous mutations within the coding region of GNAS, p.Asp189_Tyr190delinsMetfxX14, p.Val117fsX23, p.Tyr190CysfsX19, and a splicing mutation (c.659 + 1G>A), of which the latter two were novel. Five subjects with PHP-Ib exhibited complete loss of the maternal-specific methylation pattern. The remaining two PHP-Ib showed a loss of methylation of exon 1A on the maternal allele as a consequence of heterozygous 3-kb microdeletions within the STX16 gene.

CONCLUSIONS

GNAS mutation analyses and MS-MLPA assays are useful molecular tools for understanding the molecular bases and confirming the diagnosis of PHP and PPHP.

Nationwide epidemiologic survey of idiopathic osteonecrosis of the femoral head

BACKGROUND

Although numerous studies describe the clinical characteristics of idiopathic osteonecrosis of the femoral head (ONFH) in specific study populations, these have not been confirmed in countrywide studies.

QUESTIONS/PURPOSES

We therefore determined: (1) the annual number of patients seeking medical care and number of patients newly diagnosed; and (2) the distribution of the age and gender of the patients, potential causative factors, severity of the disease, and operative procedures performed.

PATIENTS AND METHODS

We conducted a nationwide epidemiologic survey in 2005. The survey included all orthopaedic departments in Japan by stratified random sampling according to the number of beds.

RESULTS

The number of patients who sought medical care for idiopathic ONFH during 2004 was estimated to be 11,400 (95% confidence interval, 10,100-12,800). We obtained clinical information from 1502 of these patients. The peak in age distribution occurred in the 40s. Potential causative factors were systemic steroid administration (51%) and habitual alcohol use (31%). Hip replacement was the most frequently performed procedure (65%). Among patients with a history of systemic steroid administration, systemic lupus erythematosus was reported most frequently (31%) as the underlying disease. Among patients younger than 40 years, steroid use was the most prominent potential causative factor (60%), and hip replacement frequently was performed (45%). A greater proportion of patients with no history of steroid or alcohol use was observed among patients 65 years or older (41%).

CONCLUSIONS

In addition to the disease burden of idiopathic ONFH in Japan, our results confirmed the importance of developing preventive and treatment strategies, especially among the younger population.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Pseudohypoparathyroidism, an often delayed diagnosis: a case series

Pseudohypoparathyroidism refers to a heterogeneous group of disorders characterized by parathyroid hormone (PTH) resistance. Pseudohypoparathyroidism is an uncommon sporadic or inherited genetic disorder subdivided into several distinct entities (type Ia, Ib, Ic, type II). We report cases of four children (aged 8 to 13 years) in the winter season 2007-'08. The present work highlights the variable mode of presentation of pseudohypoparathyroidism and the difficulty of an early diagnosis. We stress the importance of a complete biochemical investigation of the calcium-phosphate metabolism to recognize typical biochemical alterations associated with this condition (hypocalcaemia, hyperphosphataemia with increased phosphate tubular reabsorption and elevated PTH levels) in spite of a phenotypic aspect that often lacks the presence of all the peculiar clinical features of Albright hereditary osteodistrophy.

Novel gain of function mutations of the calcium-sensing receptor in two patients with PTH-deficient hypocalcemia

Among 15 patients with PTH-deficient idiopathic hypocalcemia, we found two novel missense mutations in the calcium-sensing receptor (CaSR). Patient 1, who developed severe hypocalcemia (5.0 mg/dL) and seizures after birth, had a heterozygous de novo missense mutation in the transmembrane domain (A844P). The patient is currently receiving a minimum dose of 1alpha-OHD(3) (0.5 microg/day) to maintain the serum calcium level at 6 mg/dL and thus prevent seizures. Patient 2 had asymptomatic hypocalcemia (7.5 mg/dL) and also had a heterozygous missense mutation in the extracellular domain (E228G). These findings suggest that gene analysis of CaSR should be performed in patients with idiopathic hypocalcemia, particularly when it occurs in the neonatal period.

Hypoparathyroidism in systemic lupus erythematosus

Hypoparathyroidism is a rare disease. The main cause of hypoparathyroidism is postsurgical hypoparathyroidism. However, cases of hypoparathyroidism in patients suffering from SLE exist although it is uncommon. Only three previous cases have been reported. We present the case of a woman suffering both from systemic lupus erythematosus and hypoparathyroidism. This reported association of hypoparathyroidism with lupus expands the spectrum of endocrine disorders seen in this disease. We suggest that there may be a common underlying pathophysiological process linking these diseases.

Association lupus systémique et hypoparathyroïdie : à propos d’un cas

Hypoparathyroidism is very rarely diagnosed in patients with lupus.

CASE

A 39-year-old women had systemic lupus erythematosus known for 3 years. She was admitted for a paresthesia of the lower limb, depression, insomnia and 5 kg weight loss. The laboratory tests revealed hypoparathyroidism and no sign of disease activity. Treatment with oral calcium and vitamin D resulted in correction of the hypocalcemia and QT prolongation.

DISCUSSION

The combined diagnosis lupus-hypoparathyroidism has very rarely been reported. We suggest there may be a common underlying pathological process linking the two diseases. The occurrence of these diseases in the same individual may be related to an underlying genetic predisposition or secondary to the generalized autoimmune disease process.

Hypocalcemic myopathy without tetany due to idiopathic hypoparathyroidism: case report

Myopathy due to idiopathic hypoparathyroidism is very unusual. We report on a 30 years-old man referred with complaints of sporadic muscle pain and mild global weakness for 10 years. His physical examination showed normal strength in distal muscle and slightly weakness in the pelvic and scapular girdles with no atrophy. Deep muscle reflexes were slightly hypoactive. Trousseau's and Chvostek's signs were absent. He had bilateral cataract and complex partial seizures. His laboratory tests showed decreased ionised and total calcium and parathyroid hormone and increased muscle enzymes. EMG and muscle biopsy was compatible with metabolic myopathy. After treatment with calcium and vitamin D supplementation he showed clinical, neurophisiological and laboratorial improvement. In conclusion: patients with muscle symptoms, even when non-specific and with normal neurological examination, should have serum calcium checked, as myopathy due to idiopathic hypoparathyroidism, even being rare, is treatable and easy to diagnose.

Prevalence and clinico-epidemiology of familial Graves' disease in Japan based on nationwide epidemiologic survey in 2001

A nationwide epidemiologic survey of familial Graves' disease (GD) was conducted in 2001. "Familial GD" was defined as a patient who had at least one Graves' patient within the proband's first-degree relatives. The primary survey was performed for estimating the prevalence of patients among a random selection of 2367 departments/hospitals of internal medicine, endocrinology, thyroidology and pediatrics. Of those receiving the primary questionnaire, 1361 (57.5%) responded, and 902 familial GD patients who visited them in 2000 were reported. The total number of patients was estimated to be 2850 (95% confidence intervals: 2100-3600). Based on the nationwide survey concerning the prevalence of hyperthyroidism in 1999, 2.1-3.1% of hyperthyroidism appeared to be familial GD and the relative risk of familial GD was roughly estimated to be 19-42. Subsequently, a second survey was carried out for obtaining the clinicoepidemiologic features of those patients. Of 902 patients, 487 (54%) were reported. No significant differences between familial and non-familial GD were found in age and sex distributions, clinical features or laboratory findings. Familial GD possessed the highest association with Hashimoto's thyroiditis, approximately 8% within the first-degree relatives, suggesting a shared genetic predisposition. These findings confirm the familial clustering of GD in the Japanese population, indicating the importance of environmental factors, genetic factors or both in the development of the disease.