Hypoparathyroidism and autoimmunity in the 22q11.2 deletion syndrome

Short Report: Clinical Features and Epilepsy Monitoring in an Adult With 22q11.2 Deletion Syndrome

Background

22q11.2 microdeletion is the most common microdeletion syndrome in humans with a prevalence of 13 per 100 000 live births, and it is a multisystem condition with variable phenotypic presentations.

Methods

We present a case of an adult patient with Dandy-Walker syndrome who presented to our epilepsy clinic with 2 years of new-onset seizures and cognitive decline and 1 year of psychotic symptoms.

Results

Patient had a non-revealing autoimmune and malignancy work-up. Continuous scalp vEEG study showed bursts of 1-2 Hz generalized fronto-centrally predominant spike or polyspike and slow wave discharges. Several myoclonic jerks were time-locked with the generalized discharges indicative of cortical myoclonus. MRI brain revealed periventricular nodular heterotopia in addition to findings suggestive of Dandy-Walker syndrome. Array-based comparative genomic hybridization demonstrated a 22q11.2 microdeletion seen in 22q11.2 deletion syndrome.

Conclusion

Our case illustrates the challenges of diagnosing genetic disorders in adults especially when the initial diagnosis is dependent on a number of factors, including the patient's age, the severity of the phenotypic features, and the awareness of the physician.

Inborn Errors of Immunity and Autoimmune Disease

Autoimmunity may be a manifestation of inborn errors of immunity, specifically as part of the subgroup of primary immunodeficiency known as primary immune regulatory disorders. However, although making a single gene diagnosis can have important implications for prognosis and management, picking patients to screen can be difficult, against a background of a high prevalence of autoimmune disease in the population. This review compares the genetics of common polygenic and rare monogenic autoimmunity, and explores the molecular mechanisms, phenotypes, and inheritance of autoimmunity associated with primary immune regulatory disorders, highlighting the emerging importance of gain-of-function and non-germline somatic mutations. A novel framework for identifying rare monogenic cases of common diseases in children is presented, highlighting important clinical and immunologic features that favor single gene disease and guides clinicians in selecting appropriate patients for genomic screening. In addition, there will be a review of autoimmunity in non-genetically defined primary immunodeficiency such as common variable immunodeficiency, and of instances where primary autoimmunity can result in clinical phenocopies of inborn errors of immunity.

Chromosome 22q11.2 Deletion Syndrome: A Comprehensive Review of Molecular Genetics in the Context of Multidisciplinary Clinical Approach

The 22q11.2 deletion syndrome is a multisystemic disorder characterized by a marked variability of phenotypic features, making the diagnosis challenging for clinicians. The wide spectrum of clinical manifestations includes congenital heart defects-most frequently conotruncal cardiac anomalies-thymic hypoplasia and predominating cellular immune deficiency, laryngeal developmental defects, midline anomalies with cleft palate and velar insufficiency, structural airway defects, facial dysmorphism, parathyroid and thyroid gland hormonal dysfunctions, speech delay, developmental delay, and neurocognitive and psychiatric disorders. Significant progress has been made in understanding the complex molecular genetic etiology of 22q11.2 deletion syndrome underpinning the heterogeneity of clinical manifestations. The deletion is caused by chromosomal rearrangements in meiosis and is mediated by non-allelic homologous recombination events between low copy repeats or segmental duplications in the 22q11.2 region. A range of genetic modifiers and environmental factors, as well as the impact of hemizygosity on the remaining allele, contribute to the intricate genotype-phenotype relationships. This comprehensive review has been aimed at highlighting the molecular genetic background of 22q11.2 deletion syndrome in correlation with a clinical multidisciplinary approach.

Updated clinical practice recommendations for managing adults with 22q11.2 deletion syndrome

This review aimed to update the clinical practice guidelines for managing adults with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society recruited expert clinicians worldwide to revise the original clinical practice guidelines for adults in a stepwise process according to best practices: (1) a systematic literature search (1992-2021), (2) study selection and synthesis by clinical experts from 8 countries, covering 24 subspecialties, and (3) formulation of consensus recommendations based on the literature and further shaped by patient advocate survey results. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text review, with 2318 meeting inclusion criteria (clinical care relevance to 22q11.2DS) including 894 with potential relevance to adults. The evidence base remains limited. Thus multidisciplinary recommendations represent statements of current best practice for this evolving field, informed by the available literature. These recommendations provide guidance for the recognition, evaluation, surveillance, and management of the many emerging and chronic 22q11.2DS-associated multisystem morbidities relevant to adults. The recommendations also address key genetic counseling and psychosocial considerations for the increasing numbers of adults with this complex condition.

Hypoparathyroidism and late-onset hypogonadism in an adult male with familial 22q11.2 deletion syndrome: a case report with 3-year follow-up and review of the literature

BACKGROUND

22q11.2 deletion syndrome (DiGeorge syndrome) is associated with multiple organ dysfunctions such as cardiac defects, immunodeficiency, and hypoplasia of parathyroid glands. Moreover, the phenotype of 22q11.2 DS has clinical variability and heterogeneity.

CASE PRESENTATION

In this report, we present the case of a 35-year-old patient with a past medical history that included recurrent infections, mild learning difficulties in childhood, pediatric obesity, and cataract. He was admitted to the endocrinology department for the management of hypogonadism and hypocalcemia. During the 3-year follow-up, the patient gradually developed primary hypoparathyroidism, hypogonadism, chronic renal failure, and heart failure, and his medical condition deteriorated. Meanwhile, in order to improve clinicians' awareness of the endocrine manifestations of adult 22q11.2 DS and reduce missed diagnoses, we reviewed 28 case reports of adult 22q11.2 DS to analyze the clinical characteristics.

DISCUSSION

Here, we report the case of a young man diagnosed with 22q11.2 DS presented a rare combination of multiple endocrine disorders. This is the first time that a patient with 22q11.2DS had late-onset hypogonadism caused by primary testicular failure combined with decreased pituitary gonadotropin reserve in a patient with 22q11.2DS.

Surgical insights and management in patients with the 22q11.2 deletion syndrome

PURPOSE

22q11.2 deletion syndrome (22q11.2DS) can present with a variety challenges to patients and their caregivers, many of which require surgical evaluation and intervention. Surgical needs can also extend long into adulthood, prompting evaluation and intervention throughout development and beyond. Here, we identify common concerns and patient needs associated with the 22q11.2DS from a general surgery perspective, their management, and typical management based on our institution's experience with 1263 patients.

METHODS

1263 patients evaluated and treated at the 22q And You Center at the Children's Hospital of Philadelphia were enrolled and included in the study, from January 1992 to May 2017 Co-morbidities, procedures, and imaging studies performed were quantified and assessed via descriptive analysis.

RESULTS

Gastroesophageal reflux disease (GERD) and feeding difficulties were the most common surgical issues identified, while gastrostomy tube placement, anorectal procedures, and hernia repairs were the most common surgical interventions performed by general surgeons.

CONCLUSIONS

General surgical procedures are commonly needed in this population and are part of the complex needs these patients and their surgeons may encounter in the setting of a 22q11.2DS diagnosis. These findings will help to inform a well-coordinated, multidisciplinary approach to care.

Autoimmunity in Primary Immunodeficiencies (PID)

Primary immunodeficiency (PID) may impact any component of the immune system. The number of PID and immune dysregulation disorders is growing steadily with advancing genetic detection methods. These expansive recognition methods have changed the way we characterize PID. While PID were once characterized by their susceptibility to infection, the increase in genetic analysis has elucidated the intertwined relationship between PID and non-infectious manifestations including autoimmunity. The defects permitting opportunistic infections to take hold may also lead the way to the development of autoimmune disease. In some cases, it is the non-infectious complications that may be the presenting sign of PID autoimmune diseases, such as autoimmune cytopenia, enteropathy, endocrinopathies, and arthritis among others, have been reported in PID. While autoimmunity may occur with any PID, this review will look at certain immunodeficiencies most often associated with autoimmunity, as well as their diagnosis and management strategies.

Retrospective identification of prenatal fetal anomalies associated with diagnostic neonatal genomic sequencing results

OBJECTIVE

To determine which types of fetal anomalies are associated with postnatal diagnoses of genetic diseases by genomic sequencing and to assess how prenatal genomic sequencing could affect clinical management.

METHOD

This was a secondary analysis of the second Newborn Sequencing in Genomic Medicine and Public Health study that compared fetal imaging results in critically ill infants who had actionable versus negative postnatal genomic sequencing results.

RESULTS

Of 213 infants who received genomic sequencing, 80 had available prenatal ultrasounds. Twenty-one (26%) of these were found to have genetic diseases by genomic sequencing. Fourteen (67%) of the 21 with genetic diseases had suspected anomalies prenatally, compared with 33 (56%) of 59 with negative results. Among fetuses with suspected anomalies, genetic diseases were 4.5 times more common in those with multiple anomalies and 6.7 times more common in those with anomalies of the extremities compared to those with negative results. Had the genetic diseases been diagnosed prenatally, clinical management would have been altered in 13 of 14.

CONCLUSION

Critically ill infants with diagnostic genomic sequencing were more likely to have multiple anomalies and anomalies of the extremities on fetal imaging. Among almost all infants with suspected fetal anomalies and diagnostic genomic sequencing results, prenatal diagnosis would have likely altered clinical management.

Endocrinopathies in Inborn Errors of Immunity

Inborn errors of immunity (IEI), caused by hereditary or genetic defects, are a group of more than 400 disorders, in which the immune system, including lymphocytes, neutrophils, macrophages, and complements, does not function properly. The endocrine system is frequently affected by IEI as an associated clinical feature and a complex network of glands which regulate many important body functions, including growth, reproduction, homeostasis, and energy regulation. Most endocrine disorders associated with IEI are hypofunction which would be treated with supplementation therapy, and early diagnosis and appropriate management are essential for favorable long-term outcomes in patients with IEI. In this review, we aimed to comprehensively summarize and discuss the current understanding on the clinical features and the pathophysiology of endocrine disorders in IEI. This review is composed with three parts. First, we discuss the two major pathophysiology of endocrinopathy in IEI, autoimmune response and direct effects of the responsible genes. Next, the details of each endocrinopathy, such as growth failure, hypothyroidism, hypoparathyroidism, adrenal insufficiency, diabetes mellitus (DM) are specified. We also illustrated potential endocrinopathy due to hematopoietic stem cell transplantation, including hypogonadism and adrenal insufficiency due to glucocorticoid therapy.

Symptomatic hypocalcemia after treatment for hyperthyroidism in a woman with chromosome 22q11.2 deletion syndrome complicated by Graves' disease: longitudinal changes in the number of subsets of CD4 and CD8 lymphocytes after thyroidectomy

Chromosome 22q11.2 deletion syndrome is a multisystem genetic disorder that presents with hypocalcemia due to congenital hypoparathyroidism; cardiovascular, renal, and facial anomalies; and skeletal defects. This syndrome is also associated with an increased risk of autoimmune disease. We report here on a 33-year-old Japanese woman with 22q11.2 deletion syndrome complicated by Graves' disease. The patient had facial abnormalities and a history of a surgical procedure for a submucous cleft palate at age 3 years. At age 33, the patient was diagnosed with Graves' disease because both hyperthyroidism and thyroid stimulating hormone receptor antibody were present. The patient's serum calcium level was within the normal range, but symptomatic hypocalcemia developed 1 month after treatment with methimazole was started for thyrotoxicosis. Methimazole was discontinued because it caused liver dysfunction, so the patient underwent total thyroidectomy to treat her Graves' disease. We examined longitudinal changes in the number of subsets of CD4 and CD8 lymphocytes, including regulatory T (T reg) cells and PD-1⁺CD4⁺ and PD-1⁺CD8⁺ T cells, after treatment by total thyroidectomy. A flowcytometry analysis demonstrated that circulating PD-1⁺CD4⁺ and PD-1⁺CD8⁺ T cells gradually decreased over time, as did circulating T reg cells and circulating CD19⁺ B cells. These findings suggest that PD-1-positive CD4⁺ and CD8⁺ T cells and T reg cells may have been associated with the autoimmunity in our patient with chromosome 22q11.2 deletion syndrome complicated by Graves' disease.

A Rare Etiology of Hypocalcemic Seizures in Adulthood: Clues to Diagnosis from Facial Dysmorphism

We report a 40-year-old male who presented with seizures due to hypocalcemia. Biochemical evaluation revealed the diagnosis of hypoparathyroidism. The symptom complex of dysmorphic facies and intellectual disability along with hypoparathyroidism led to a suspicion of 22q11.2 microdeletion syndrome (22q11.2DS), which was confirmed by multiplex ligation-dependent probe amplification (MLPA) analysis showing 22q11.2.21 microdeletion.

Vitamin D status and the immune assessment in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.

Complement Activation in 22q11.2 Deletion Syndrome

The 22q11.2 deletion syndrome (22q11.2 del), also known as DiGeorge syndrome, is a genetic disorder with an estimated incidence of 1:3000 to 1:6000 births. These patients may suffer from affection of many organ systems with cardiac malformations, immunodeficiency, hypoparathyroidism, autoimmunity, palate anomalies, and psychiatric disorders being the most frequent. The importance of the complement system in 22q11.2 del has not been investigated. The objective of this study was to evaluate the complement system in relation to clinical and immunological parameters in patients. A national cohort of patients (n = 69) with a proven heterozygous deletion of chromosome 22q11.2 and a group of age and sex matched controls (n = 56) were studied. Functional capacity of the classical, lectin, and alternative pathways of the complement system as well as complement activation products C3bc and terminal complement complex (TCC) were accessed and correlated to clinical features. All patients in our study had normal complement activation in both classical and alternative pathways. The frequency of mannose-binding lectin deficiency was comparable to the normal population. The patients had significantly raised plasma levels of C3bc and a slight, but not significant, increase in TCC compared with controls. This increase was associated with the presence of psychiatric disorders in patients. The present study shows no complement deficiencies in 22q11.2 deletion syndrome. On the contrary, there are signs of increased complement activation in these patients. Complement activation is particularly associated with the presence of psychiatric disorders.

Autoimmune Thyroid Disease in Specific Genetic Syndromes in Childhood and Adolescence

Autoimmune thyroid disease (ATD) is the most frequent cause of acquired thyroid dysfunction, most commonly presenting either as Hashimoto's thyroiditis or Graves' Disease. Hashimoto's thyroiditis is characterized by the presence of thyroid-specific autoantibodies, more commonly anti-thyroperoxidase antibodies in the serum and the typical inhomogeneous echostructure of the thyroid on a thyroid ultrasound examination. Hashimoto's thyroiditis can for a long time be accompanied by normal thyroid function and hypothyroidism can only progressively be established. Graves' disease is much less frequent in childhood and adolescence and presents with overt hyperthyroidism. After the onset of puberty, ATD affects females with a higher incidence than males, while during the prepubertal period there is not such a clear preponderance of affected females. ATD can occur either isolated or in the context of other autoimmune disorders, such as type 1 Diabetes mellitus (T1D), celiac disease, alopecia areata, vitiligo, etc. Especially at the pediatric age, a higher incidence of ATD is also observed in the context of specific genetic syndromes, such as trisomy 21 (Down syndrome), Klinefelter syndrome, Turner syndrome, or 22q11.2 deletion syndrome. Nevertheless, although thyroid dysfunction may also be observed in other genetic syndromes, such as Prader-Willi or Williams syndrome, the thyroid dysfunction in these syndromes is not the result of thyroid autoimmunity. Interestingly, there is emerging evidence supporting a possible link between autoimmunity and RASopathies. In this review article the incidence, as well as the clinical manifestation and accompanied pathologies of ATD in specific genetic syndromes will be presented and regular follow-up for the early identification of the disorder will be proposed.

Calcium, vitamin D or recombinant parathyroid hormone for managing post-thyroidectomy hypoparathyroidism

BACKGROUND

Post-surgical hypoparathyroidism is a common complication after thyroid surgery. The incidence is likely to increase given the rising trend in the annual number of thyroid operations being performed. Measures to prevent post-thyroidectomy hypoparathyroidism including different surgical techniques and prophylactic calcium and vitamin D supplements have been extensively studied. The management of post-thyroidectomy hypoparathyroidism however has not been extensively evaluated. Routine use of calcium and vitamin D supplements in the postoperative period may reduce the risk of symptoms, temporary hypocalcaemia and hospital stay. However, this may lead to overtreatment and has no effect on long-term hypoparathyroidism. Current recommendations on the management of post-thyroidectomy hypoparathyroidism is based on low-quality evidence. Existing guidelines do not often distinguish between surgical and non-surgical hypoparathyroidism, and transient and long-term disease.The aim of this systematic review was to summarise evidence on the use of calcium, vitamin D and recombinant parathyroid hormone in the management of post-thyroidectomy hypoparathyroidism. In addition, we aimed to highlight deficiencies in the current literature and stimulate further work in this field.

OBJECTIVES

The objective of this systematic review was to assess the effects of calcium, vitamin D and recombinant parathyroid hormone in managing post-thyroidectomy hypoparathyroidism.

SEARCH METHODS

We searched CENTRAL, MEDLINE, PubMed, Embase as well as ICTRP Search Portal and ClinicalTrials.gov. The date of the last search for all databases was 17 December 2018 (except Embase, which was last searched on 21 December 2017). No language restrictions were applied.

SELECTION CRITERIA

We planned to include randomised control trials (RCTs) or controlled clinical trials (CCTs) examining the effects of calcium, vitamin D or recombinant parathyroid hormone in people with temporary and long-term post-thyroidectomy hypoparathyroidism.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full texts for relevance.

MAIN RESULTS

Database searches yielded a total of 1751 records. We retrieved potentially relevant full texts and excluded articles on the following basis: not a RCT or CCT; intervention, comparator or both did not match prespecified criteria; non-surgical causes of hypoparathyroidism, and studies on prevention. None of the articles was eligible for inclusion in the systematic review.

AUTHORS' CONCLUSIONS

This systematic review highlights a gap in the current literature and the lack of high-quality evidence in the management of post-thyroidectomy temporary and long-term hypoparathyroidism. Further research focusing on clinically relevant outcomes is needed to examine the effects of current treatments in the management of temporary and long-term post-thyroidectomy hypocalcaemia.

Primary immunodeficiency and autoimmunity: A comprehensive review

The primary immunodeficiency diseases (PIDs) include many genetic disorders that affect different components of the innate and adaptive responses. The number of distinct genetic PIDs has increased exponentially with improved methods of detection and advanced laboratory methodology. Patients with PIDs have an increased susceptibility to infectious diseases and non-infectious complications including allergies, malignancies and autoimmune diseases (ADs), the latter being the first manifestation of PIDs in several cases. There are two types of PIDS. Monogenic immunodeficiencies due to mutations in genes involved in immunological tolerance that increase the predisposition to develop autoimmunity including polyautoimmunity, and polygenic immunodeficiencies characterized by a heterogeneous clinical presentation that can be explained by a complex pathophysiology and which may have a multifactorial etiology. The high prevalence of ADs in PIDs demonstrates the intricate relationships between the mechanisms of these two conditions. Defects in central and peripheral tolerance, including mutations in AIRE and T regulatory cells respectively, are thought to be crucial in the development of ADs in these patients. In fact, pathology that leads to PID often also impacts the Treg/Th17 balance that may ease the appearance of a proinflammatory environment, increasing the odds for the development of autoimmunity. Furthermore, the influence of chronic and recurrent infections through molecular mimicry, bystander activation and super antigens activation are supposed to be pivotal for the development of autoimmunity. These multiple mechanisms are associated with diverse clinical subphenotypes that hinders an accurate diagnosis in clinical settings, and in some cases, may delay the selection of suitable pharmacological therapies. Herein, a comprehensively appraisal of the common mechanisms among these conditions, together with clinical pearls for treatment and diagnosis is presented.

[Child psychiatry interventions in patients with 22q11 deletion syndrome: From treatment to prevention]

22q11.2DS is one of the more frequent genetic syndromes associated to psychiatric symptoms. It has been associated to an increased risk to develop schizophrenia in adolescence or early adulthood. However, psychiatric symptoms appear early on, and should be recognized as soon as possible by child psychiatrists in order to improve the present well-being of children and their family, and to prevent further risks of developing severe and chronic psychiatric diseases later on. In this paper, we present a review of the recent literature concerning the 22q11.2DS syndrome focused on the risk factors that may be associated to an increased risk of psychotic transition. We advocate for the development of systematic specialized child psychiatry consultations for these patients, included in networks with geneticists, adult psychiatrists, and family associations, in order to improve their psychiatric prognosis and to support the development of translational research.

Hypocalcemia due to 22q11.2 deletion syndrome diagnosed in adulthood

Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a genetic syndrome that may present with hypocalcemia due to primary hypoparathyroidism (PH) at any age. We report a new diagnosis of 22q11.2DS in a 57-year-old man who presented with symptomatic hypocalcemia. It is important to consider genetic causes of hypocalcemia due to PH regardless of age.

Learning points

It is important to discard genetic cause of primary hypoparathyroidism in a patient without autoimmune disease or prior neck surgery.A new diagnosis of a hereditary disease has familial implications and needs genetic counselling.It is also important to discard other syndrome's comorbidities.

Increased Levels of Interferon-Inducible Protein 10 (IP-10) in 22q11.2 Deletion Syndrome

The 22q11.2 deletion syndrome (22q11.2 DS), also known as DiGeorge syndrome, is a genetic disorder with an estimated incidence of 1:4000 births. These patients may suffer from affection of many organ systems with cardiac malformations, thymic hypoplasia or aplasia, hypoparathyroidism, palate anomalies and psychiatric disorders being the most frequent. The incidence of autoimmune diseases is increased in older patients. The aim of the present study was to examine a cytokine profile in patients with 22q11.2 DS by measuring a broad spectrum of serum cytokines. Patients with a proven deletion of chromosome 22q11.2 (n = 55) and healthy individuals (n = 54) recruited from an age- and sex-comparable group were included in the study. Serum levels of 27 cytokines, including chemokines and growth factors, were analysed using multiplex technology. Interferon-inducible protein 10 (IP-10) was also measured by ELISA to confirm the multiplex results. The 22q11.2 DS patients had distinctly and significantly raised levels of pro-inflammatory and angiostatic chemokine IP-10 (P < 0.001) compared to controls. The patients with congenital heart defects (n = 31) had significantly (P = 0.018) raised serum levels of IP-10 compared to patients born without heart defects (n = 24). The other cytokines investigated were either not detectable or did not differ between patients and controls.

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.

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.

European Society of Endocrinology Clinical Guideline: Treatment of chronic hypoparathyroidism in adults

Hypoparathyroidism (HypoPT) is a rare (orphan) endocrine disease with low calcium and inappropriately low (insufficient) circulating parathyroid hormone levels, most often in adults secondary to thyroid surgery. Standard treatment is activated vitamin D analogues and calcium supplementation and not replacement of the lacking hormone, as in other hormonal deficiency states. The purpose of this guideline is to provide clinicians with guidance on the treatment and monitoring of chronic HypoPT in adults who do not have end-stage renal disease. We intend to draft a practical guideline, focusing on operationalized recommendations deemed to be useful in the daily management of patients. This guideline was developed and solely sponsored by The European Society of Endocrinology, supported by CBO (Dutch Institute for Health Care Improvement) and based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) principles as a methodological base. The clinical question on which the systematic literature search was based and for which available evidence was synthesized was: what is the best treatment for adult patients with chronic HypoPT? This systematic search found 1100 articles, which was reduced to 312 based on title and abstract. The working group assessed these for eligibility in more detail, and 32 full-text articles were assessed. For the final recommendations, other literature was also taken into account. Little evidence is available on how best to treat HypoPT. Data on quality of life and the risk of complications have just started to emerge, and clinical trials on how to optimize therapy are essentially non-existent. Most studies are of limited sample size, hampering firm conclusions. No studies are available relating target calcium levels with clinically relevant endpoints. Hence it is not possible to formulate recommendations based on strict evidence. This guideline is therefore mainly based on how patients are managed in clinical practice, as reported in small case series and based on the experiences of the authors.

22q11 deletion syndrome: current perspective

Chromosome 22q11 is characterized by the presence of chromosome-specific low-copy repeats or segmental duplications. This region of the chromosome is very unstable and susceptible to mutations. The misalignment of low-copy repeats during nonallelic homologous recombination leads to the deletion of the 22q11.2 region, which results in 22q11 deletion syndrome (22q11DS). The 22q11.2 deletion is associated with a wide variety of phenotypes. The term 22q11DS is an umbrella term that is used to encompass all 22q11.2 deletion-associated phenotypes. The haploinsufficiency of genes located at 22q11.2 affects the early morphogenesis of the pharyngeal arches, heart, skeleton, and brain. TBX1 is the most important gene for 22q11DS. This syndrome can ultimately affect many organs or systems; therefore, it has a very wide phenotypic spectrum. An increasing amount of information is available related to the pathogenesis, clinical phenotypes, and management of this syndrome in recent years. This review summarizes the current clinical and genetic status related to 22q11DS.

An increased prevalence of thyroid disease in children with 22q11.2 deletion syndrome

We reviewed the health records of pediatric patients with 22q11.2 deletion syndrome (22q11.2 DS) seen over a 5-year period in our 22q11.2 DS multidisciplinary clinic. We determined the prevalence of thyroid dysfunction in this population, in comparison to general population data. Statistical tests were applied to investigate trends in gender differences, thyroid disease subtype and co-morbid conditions in the patients identified with thyroid disease. Of 169 subjects (92 male, 77 female) 9.5% had overt thyroid disease; of these, 1.8% had hyperthyroidism and 7.7% had hypothyroidism; 42% of patients with subclinical or prodromal thyroid disease progressed to overt disease. Our data indicate that thyroid disease prevalence in the 22q11DS pediatric population is significantly higher than that in the general pediatric population Furthermore, over 1/3 of patients in our study population who presented with subclinical thyroid disease progressed to overt disease, requiring medical therapy. Thyroid disease screening should be incorporated into routine medical management of children with 22q11.2 DS. Guidelines for screening individuals with 22q11.2 DS are presented.

Primary immunodeficiency diseases: a primer for PCPs

Primary care providers (PCPs) play a key role in identifying patients with primary immunodeficiency diseases (PIDDs). This diagnosis has implications for PCPs, as patients continue to require primary care and management after a PIDD diagnosis has been made. This review presents essential information for PCPs regarding PIDDs.

3 generation pedigree with paternal transmission of the 22q11.2 deletion syndrome: Intrafamilial phenotypic variability

In this case report, we present a paternal transmission of a classic 3 Mb 22q11.2 deletion syndrome (22q11.2 DS) in a 3 generation family. In this family a young girl, her father, her uncle and her grandfather were diagnosed with this disorder. All carriers showed phenotypic expression, there were no unaffected siblings in the second or third generation. Presenting symptoms in the patient in first generation (grandfather) were psoriatic arthritis, thrombocytopenia and a right aortic arch. There was no intellectual disability. The second generation uncle was known with a severe intellectual disability, mild facial characteristics, a septal defect and a clubfoot, whereas the second generation father had a tetralogy of Fallot, no intellectual disability and minimal facial characteristics. The third generation daughter had a moderate intellectual disability, hypernasal speech, triphalangeal thumb, severe speech and language development delay, pronounced facial characteristics and a diagnosis of ADHD. It was notable that the expression in the two brothers of the second generation gives two very different clinical phenotypes with a severe intellectual disability in the oldest brother. This report describes a pronounced clinical variability in a 3 generation familial 22q11.2 deletion with paternal transmission. We can assume that several mechanisms play an important role in the heterogeneity and part of the answer should be found in the genetic background underlying the 22q11.2 deletion. In addition in this family the neuropsychiatric phenotype and intellectual disability seem to be associated with a lower level of social and occupational functioning while a congenital heart disease does not. This clinical report illustrates that a detailed description of these patients can be very informative and still increase the knowledge on this heterogeneous syndrome. For the clinicians working with these patients it emphasizes the need for a multidisciplinary approach that takes into account the individual needs.

Clinical and serologic parallels to APS-I in patients with thymomas and autoantigen transcripts in their tumors

Patients with the autoimmune polyendocrine syndrome type I (APS-I), caused by mutations in the autoimmune regulator (AIRE) gene, and myasthenia gravis (MG) with thymoma, show intriguing but unexplained parallels. They include uncommon manifestations like autoimmune adrenal insufficiency (AI), hypoparathyroidism, and chronic mucocutaneous candidiasis plus autoantibodies neutralizing IL-17, IL-22, and type I IFNs. Thymopoiesis in the absence of AIRE is implicated in both syndromes. To test whether these parallels extend further, we screened 247 patients with MG, thymoma, or both for clinical features and organ-specific autoantibodies characteristic of APS-I patients, and we assayed 26 thymoma samples for transcripts for AIRE and 16 peripheral tissue-specific autoantigens (TSAgs) by quantitative PCR. We found APS-I-typical autoantibodies and clinical manifestations, including chronic mucocutaneous candidiasis, AI, and asplenia, respectively, in 49 of 121 (40%) and 10 of 121 (8%) thymoma patients, but clinical features seldom occurred together with the corresponding autoantibodies. Both were rare in other MG subgroups (n = 126). In 38 patients with APS-I, by contrast, we observed neither autoantibodies against muscle Ags nor any neuromuscular disorders. Whereas relative transcript levels for AIRE and 7 of 16 TSAgs showed the expected underexpression in thymomas, levels were increased for four of the five TSAgs most frequently targeted by these patients' autoantibodies. Therefore, the clinical and serologic parallels to APS-I in patients with thymomas are not explained purely by deficient TSAg transcription in these aberrant AIRE-deficient tumors. We therefore propose additional explanations for the unusual autoimmune biases they provoke. Thymoma patients should be monitored for potentially life-threatening APS-I manifestations such as AI and hypoparathyroidism.

Prevalence of hypocalcaemia and its associated features in 22q11·2 deletion syndrome

BACKGROUND

22q11.2 deletion syndrome (22q11.2DS) is a relatively common yet under-recognized genetic syndrome that may present with endocrine features. We aimed to address the factors that contribute to the high prevalence of hypocalcaemia.

METHODS

We investigated hypocalcaemia in a well-characterized sample of 138 adults with 22q11.2DS (65 m, 73 F; mean age 34.2, SD 11.8, years) using laboratory studies and lifelong medical records. Logistic regression modelling was used to identify features associated with lifetime prevalence of hypocalcaemia.

RESULTS

Of the total sample, 111 (80.4%) had a lifetime history of hypocalcaemia. Eleven (84.6%) of 13 subjects with neonatal hypocalcaemia had documented recurrence of hypocalcaemia. Lifetime history of hypocalcaemia was associated with lifetime prevalence of hypoparathyroidism (P < 0.0001) and hypothyroidism (P = 0.04), as statistically independent factors. Hypomagnesaemia was associated with concurrent hypocalcaemic measurements, especially in the presence of concurrent hypoparathyroidism (P = 0.02).

CONCLUSIONS

The results suggest that, in addition to the major effect of hypoparathyroidism, hypothyroidism may play a role in hypocalcaemia in 22q11.2DS and that there is a high recurrence rate of neonatal hypocalcaemia. Hypomagnesaemia may contribute to hypocalcaemia by further suppressing parathyroid hormone (PTH). Although further studies are needed, the findings support regular lifelong follow-up of calcium, magnesium, PTH and TSH levels in patients with 22q11.2DS. At any age, hypocalcaemia with hypoparathyroidism and/or hypothyroidism may suggest a diagnosis of 22q11.2DS.

Therapy of hypoparathyroidism by replacement with parathyroid hormone

Hypoparathyroidism (HypoPT) is a state of hypocalcemia due to inappropriate low levels of parathyroid hormone (PTH). HypoPT is normally treated by calcium supplements and activated vitamin D analogues. Although plasma calcium is normalized in response to conventional therapy, quality of life (QoL) seems impaired and patients are at increased risk of renal complications. A number of studies have suggested subcutaneous injections with PTH as an alternative therapy. By replacement with the missing hormone, urinary calcium may be lowered and QoL may improve. PTH replacement therapy (PTH-RT) possesses, nevertheless, a number of challenges. If PTH is injected only once a day, fluctuations in calcium levels may occur resulting in hypercalcemia in the hours following an injection. Twice-a-day injections seem to cause less fluctuation in plasma calcium but do stimulate bone turnover to above normal. Most recently, continuous delivery of PTH by pump has appeared as a feasible alternative to injections. Plasma calcium levels do not fluctuate, urinary calcium is lowered, and bone turnover is only stimulated modestly (into the normal range). Further studies are needed to assess the long-term effects. If beneficial, it seems likely that standard treatment of HypoPT in the future will change into replacement therapy with the missing hormone.

Immunological features of 22q11 deletion syndrome

PURPOSE OF REVIEW

22q11 deletion syndrome is the most common genetic abnormality. More patients are surviving cardiac surgery, and many do not have cardiac anomalies. Adult patients are now being described. It is important for paediatricians, and increasingly adult physicians, to be aware of the optimum management of these patients.

RECENT FINDINGS

Three main immunological patterns are recognized, namely, athymic and incomplete 22q11 deletion syndrome and autoimmunity. Newborn screening for severe combined immunodeficiency detects athymic patients, although diagnosis may be complicated, and instructive cases are described. Incomplete 22q11 deletion syndrome is the most common presentation; new findings predict which patients are likely to experience significant infection. B lymphocyte deficiencies are often overlooked. Data regarding autoimmunity in adult patients is reported, as well as newly reported immunological findings. Finally, management guidelines are now published, and these are highlighted.

SUMMARY

Newborn screening detects patients with athymic 22q11 deletion syndrome, but significant illness may complicate the picture, and dual diagnoses can confound treatment. Treatment options for these patients are becoming clearer. Hypoparathyroidism is associated with more severe infection, and immunoglobulin abnormalities are more common than previously recognized. Adult patients are symptomatic and management guidelines will help general physicians in managing these patients.

Neonatal hypocalcemia, neonatal seizures, and intellectual disability in 22q11.2 deletion syndrome

PURPOSE

Hypocalcemia is a common endocrinological condition in 22q11.2 deletion syndrome. Neonatal hypocalcemia may affect neurodevelopment. We hypothesized that neonatal hypocalcemia would be associated with rare, more severe forms of intellectual disability in 22q11.2 deletion syndrome.

METHODS

We used a logistic regression model to investigate potential predictors of intellectual disability severity, including neonatal hypocalcemia, neonatal seizures, and complex congenital heart disease, e.g., interrupted aortic arch, in 149 adults with 22q11.2 deletion syndrome. Ten subjects had moderate-to-severe intellectual disability.

RESULTS

The model was highly significant (P < 0.0001), showing neonatal seizures (P = 0.0018) and neonatal hypocalcemia (P = 0.047) to be significant predictors of a more severe level of intellectual disability. Neonatal seizures were significantly associated with neonatal hypocalcemia in the entire sample (P < 0.0001), regardless of intellectual level. There was no evidence for the association of moderate-to-severe intellectual disability with other factors such as major structural brain malformations in this sample.

CONCLUSION

The results suggest that neonatal seizures may increase the risk for more severe intellectual deficits in 22q11.2 deletion syndrome, likely mediated by neonatal hypocalcemia. Neonatal hypocalcemia often remains unrecognized until the postseizure period, when damage to neurons may already have occurred. These findings support the importance of early recognition and treatment of neonatal hypocalcemia and potentially neonatal screening for 22q11.2 deletions.

An adult case of 22q11.2 deletion syndrome diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis

22q11.2 Deletion syndrome is recognized to be a major cause of congenital hypoparathyroidism, and affected patients exhibit a range of autoimmune characteristics. The syndrome becomes apparent in early childhood and is rarely diagnosed in adulthood. This report describes an adult case of 22q11.2 deletion syndrome first diagnosed in a 36-year-old woman with hypocalcemia caused by hypoparathyroidism and Hashimoto's thyroiditis. It is important to diagnose 22q11.2 deletion syndrome in adults because such patients are still at high risk for developing treatable diseases, such as hypocalcemia and autoimmune diseases.

Antibody deficiency in adults with 22q11.2 deletion syndrome

There are limited data on immunological disorders, infection profile, and autoimmunity among adults with the 22q11.2 deletion syndrome (22q11.2DS) in the literature. To expand this knowledge base, we evaluated immunoglobulin levels, lymphocyte subsets, and T-cell function in 26 adults, consecutively referred to our 22q11.2DS multidisciplinary team. Their medical records were also reviewed with respect to frequency and severity of infections and autoimmune disorders. Six patients had low immunoglobulin levels; among these patients, one had a combined IgA and IgG1 deficiency, one had an isolated IgG3 deficiency, and four had a profound antibody deficiency comparable to common variable immunodeficiency (CVID). Three of the patients with profound antibody deficiency showed signs of reduced T-cell function measured as a low response to mitogen and/or antigen stimulation. The four patients with profound antibody deficiency suffered from more severe infections than the rest of the patient group. Three of them also had a history of both immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AHA). Our results suggest that a subgroup of individuals with 22q11.2DS can develop a severe antibody deficiency associated with lower respiratory tract infections and autoimmune conditions. Early diagnosis of hypogammaglobulinemia among these individuals is important in order to provide optimal treatment. We therefore recommend an immunological evaluation and follow-up among adults with 22q11.2DS who have a history of autoimmune conditions or recurrent infections.

Dental developmental disturbances in 50 individuals with the 22q11.2 deletion syndrome; relation to medical conditions?

OBJECTIVE

The aims of the study were to examine tooth and enamel disturbances in individuals with 22q11.2 deletion syndrome and to analyze associations with medical conditions, birth characteristics and blood values of calcium and PTH.

MATERIALS AND METHODS

Fifty individuals participated in the study (27 females, median age 10 years, range 1.5-44). Congenital absence of teeth was studied on orthopantomograms; 1148 teeth were examined, both clinically and radiologically, and enamel hypomineralizations and hypoplasias were recorded. Medical history and findings were recorded as part of a larger study on the manifestations of 22q11.2-deletion syndrome in Norway.

RESULTS

Tooth agenesis was observed in 15% of study participants. Sixty-six percent of the participants and 26.0% of teeth presented with enamel disturbances. Of these, 12 individuals (24.0%) and 215 teeth (18.7%) had hypomineralizations and four individuals (8.0%) and 86 teeth (7.5%) had hypoplasias. Seventeen participants (34.0%) presented with both types of disturbance, but rarely in the same tooth. Only two teeth (0.17%) had both types of disturbance. Hypomineralizations were twice as frequent in permanent as in primary teeth. No correlations were found to medical conditions, except that participants with congenital cardiac anomalies presented with fewer total enamel disturbances and hypomineralizations in permanent teeth than those without.

CONCLUSIONS

Enamel disturbances were frequently seen. There were more hypomineralizations than hypoplasias. Hypoparathyroidism and/or hypocalcemia are not clear etiological factors for enamel disturbances and there were no major correlations between medical conditions and enamel disturbances.

Fetal and Neonatal Illnesses Caused or Influenced by Maternal Transplacental IgG and/or Therapeutic Antibodies Applied During Pregnancy

The human fetus is protected by the mother’s antibodies. At the end of the pregnancy, the concentration of maternal antibodies is higher in the cord blood, than in the maternal circulation. Simultaneously, the immune system of the fetus begins to work and from the second trimester, fetal IgM is produced by the fetal immune system specific to microorganisms and antigens passing the maternal-fetal barrier. The same time the fetal immune system has to cope and develop tolerance and T_REG cells to the maternal microchimeric cells, latent virus-carrier maternal cells and microorganisms transported through the maternal-fetal barrier.

The maternal phenotypic inheritance may hide risks for the newborn, too. Antibody mediated enhancement results in dengue shock syndrome in the first 8 month of age of the baby.

A series of pathologic maternal antibodies may elicit neonatal illnesses upon birth usually recovering during the first months of the life of the offspring. Certain antibodies, however, may impair the fetal or neonatal tissues or organs resulting prolonged recovery or initiating prolonged pathological processes of the children.

The importance of maternal anti-idiotypic antibodies are believed to prime the fetal immune system with epitopes of etiologic agents infected the mother during her whole life before pregnancy and delivery.

The chemotherapeutical and biological substances used for the therapy of the mother will be transcytosed into the fetal body during the last two trimesters of pregnancy. The long series of the therapeutic monoclonal antibodies and conjugates has not been tested systematically yet. The available data are summarised in this chapter.

The innate immunity plays an important role in fetal defence. The concentration of interferon is relative high in the placenta. This is probably one reason, why the therapeutic interferon treatment of the mother does not impair the fetal development.