DiGeorge Syndrome: a not so rare disease

Comprehensive insights into health services accessibility and quality of life of families with individuals with 22q11.2 deletion syndrome in Brazil

BACKGROUND

The 22q11.2 Deletion Syndrome (22q11.2 DS) presents unique healthcare challenges for affected individuals, families, and healthcare systems. Despite its rarity, 22q11.2 DS is the most common microdeletion syndrome in humans, emphasizing the need to understand and address the distinctive healthcare requirements of those affected. This paper examines the multifaceted issue of health service access and caregivers' quality of life in the context of 22q11.2 DS in Brazil, a condition with diverse signs and symptoms requiring multidisciplinary care. This study employs a comprehensive approach to evaluate health service accessibility and the quality of life of caregivers of individuals with 22q11.2 DS. It utilizes a structured Survey and the WHOQOL-bref questionnaire for data collection.

RESULTS

Individuals with 22q11.2 DS continue to receive incomplete clinical management after obtaining the diagnosis, even in the face of socioeconomic status that enabled an average age of diagnosis that precedes that found in sample groups that are more representative of the Brazilian population (mean of 3.2 years versus 10 years, respectively). In turn, caring for individuals with 22q11.2 DS who face difficulty accessing health services impacts the quality of life associated with the caregivers' environment of residence.

CONCLUSIONS

Results obtained help bridge the research gap in understanding how caring for individuals with multisystem clinical conditions such as 22q11.2 DS and difficulties in accessing health are intertwined with aspects of quality of life in Brazil. This research paves the way for more inclusive healthcare policies and interventions to enhance the quality of life for families affected by this syndrome.

Syndromic Hearing Loss in Children

Pattern recognition of specific temporal bone radiological phenotypes, in association with abnormalities in other organ systems, is critical in the diagnosis and management of syndromic causes of hearing loss. Several recent publications have demonstrated the presence of specific radiological appearances, allowing precise genetic and/or syndromic diagnosis, in the right clinical context. This review article aims to provide an extensive but practical guide to the radiologist dealing with syndromic causes of hearing loss.

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.

Endocrine Abnormalities and Growth Characterization in Colombian Pediatric Patients with 22q11 Deletion Syndrome

OBJECTIVE

Several endocrine manifestations have been described in patients with 22q11 deletion syndrome, including growth retardation, hypoparathyroidism, and thyroid disorders. This study aimed to characterize these abnormalities in a Colombian retrospective cohort of children with this condition.

METHODS

A retrospective study comprising a cohort of children with 22q11 deletion syndrome in Medellín, Colombia followed up between 2011 and 2017 was conducted.

RESULTS

Thirty-seven patients with a confirmed diagnosis of 22q11 deletion syndrome were included. 37.8% had some endocrinopathy, the most frequent being hypoparathyroidism (21.6%), followed by hypothyroidism (13.5%), hyperthyroidism (2.7%) and growth hormone deficiency (2.7%). There was wide heterogeneity in the clinical presentation, with late onset of severe hypocalcemia associated with seizure or precipitated in postoperative cardiac surgery, which highlights the importance of continuous follow-up as indicated by the guidelines. Short stature was mainly related to nutritional factors. Growth monitoring is required with the use of syndrome-specific charts and careful monitoring of the growth rate.

CONCLUSION

As previously reported, a significant proportion of patients with endocrine abnormalities were found in this cohort. This highlights that it is essential to carry out an adequate multidisciplinary follow-up, based on the specific clinical guidelines, in order to avoid serious complications such as convulsions due to hypocalcemia. It is important to track size with curves specific to the syndrome and analyze the growth rate.

Neuroinflammation and Oxidative Stress in Individuals Affected by DiGeorge Syndrome

DiGeorge syndrome (DGS) is a rare genetic disease caused by microdeletions of the 22q11.2 region (DGS1). A haploinsufficiency at 10p level has been proposed also as a DGS cause (DGS2). Clinical manifestations are variable. The most frequent features are thymic hypoplasia or aplasia with consequent immune deficiency, cardiac malformations, hypoparathyroidism, facial and palatine abnormalities, variable degrees of cognitive impairment and psychiatric disorders. The specific aim of this descriptive report is to discuss the correlation between oxidative stress and neuroinflammation in DGS patients with microdeletions of the 22q11.2 region. The deleted chromosomic region maps various genes involved in mitochondrial metabolisms, such as DGCR8 and TXNRD2, that could lead to reactive oxygen species (ROS) increased production and antioxidant depletion. Furthermore, increased levels of ROS in mitochondria would lead to the destruction of the projection neurons in the cerebral cortex with consequent neurocognitive impairment. Finally, the increase in modified protein belonging to the family of sulfoxide compounds and hexoses, acting as inhibitors of the IV and V mitochondria complex, could result in direct ROS overproduction. Neuroinflammation in DGS individuals could be directly related to the development of the syndrome's characteristic psychiatric and cognitive disorders. In patients with psychotic disorders, the most frequent psychiatric manifestation in DGS, Th-17, Th-1 and Th-2 cells are increased with consequent elevation of proinflammatory cytokine IL-6 and IL1β. In patients with anxiety disorders, both CD3 and CD4 are increased. Some patients with autism spectrum disorders (ASDs) have an augmented level of proinflammatory cytokines IL-12, IL-6 and IL-1β, while IFNγ and the anti-inflammatory cytokine IL-10 seem to be reduced. Other data proposed that altered synaptic plasticity could be directly involved in DGS cognitive disorders. In conclusion, the use of antioxidants for restoring mitochondrial functionality in DGS could be a useful tool to protect cortical connectivity and cognitive behavior.

Infectious Complications of DiGeorge Syndrome in the Setting of Malignancy

This report describes a case of a young man with DiGeorge Syndrome, repaired Tetralogy of Fallot, relapsed metastatic Hodgkin’s Lymphoma, immunodeficiency, and a history of recurrent and severe infections. A review of the literature indicates that patients with DiGeorge Syndrome are at greater risk for infection, malignancy, and cardiac events due to anatomic and immunologic complications resulting from a deletion in the 22q11.2 chromosome. As an increased number of patients with DiGeorge Syndrome are surviving into adulthood, it is important to understand the progression of the disease and the long-term implications associated with variable degrees of thymic hypoplasia and immune deficiency. 

Investigação Citogenômica de Crianças com Doença Cardíaca Congênita: Experiência de um Centro no Brasil

Fundamento

Algumas síndromes têm características específicas e facilmente reconhecíveis, enquanto outras podem ser mais complexas de se identificar e podem apresentar diferentes manifestações fenotípicas, por exemplo. Um diagnóstico etiológico é importante para entender a natureza da doença, para estabelecer o prognóstico e para começar o tratamento, permitindo a inclusão de pacientes na sociedade e reduzindo o custo financeiro dessas doenças.

Objetivo

A proposta inicial deste estudo foi a triagem citogenética para detectar a síndrome de deleção 22q11.2 (SD22q11.2) em recém-nascidos e crianças com doença cardíaca congênita utilizando a técnica da amplificação multiplex de sondas dependente de ligação (MLPA). Assim, por meio da pesquisa, outras mudanças genômicas foram identificadas nesses pacientes cardíacos. Nosso objetivo se estendeu a investigar essas outras mudanças citogenéticas.

Métodos

Investigamos 118 recém-nascidos com doenças cardíacas congênitas nascidos consecutivamente durante um ano, utilizando a técnica da MLPA.

Resultados

A técnica da MLPA permitiu a detecção da SD22q11.2 em 10/118 pacientes (8,5%). Outras alterações genômicas foram identificadas em 6/118 pacientes (5%): 1p36 del, 8p23 del (2 casos), 7q dup, 12 dup e 8q24 dup.

Conclusão

Este estudo ressalta a relevância da detecção de alterações genômicas que estão presentes em recém-nascidos e crianças com doenças cardíacas congênitas por meio de ferramentas citogenômicas.

Autoimmune hemolytic anemia associated with vitamin B12 deficiency and viral illness in DiGeorge syndrome. Case report and literature review

Vitamin B12 plays a crucial role in cell maturation and differentiation. Its deficiency can lead to cytopenias and even hemolysis. We suggest regular monitoring and maintenance of Vit B12 levels in DiGeorge syndrome patients to prevent such triggers.

Late diagnosed DiGeorge syndrome in a 44-year-old female: a rare cause for recurrent syncopes in adulthood-a case report

Background

DiGeorge syndrome, also known as ‘CATCH 22’, is the most common deletion in humans and is one of the velocardiofacial syndromes. It is characterized by a specific facial phenotype, and structural and functional abnormalities in the cardiac and endocrine systems. One form of endocrine system dysfunction is hypocalcaemia, which causes arrhythmic events and can result in a transient loss of consciousness. We present a case highlighting the late diagnosis of DiGeorge syndrome in a patient with recurrent episodes of syncope due to suspected arrhythmic events secondary to hypocalcaemia.

Case summary

A 44-year-old woman was referred for further investigation of recurrent syncope episodes and documented transient QT-prolongation with hypocalcaemia. Previous detailed cardiological examination, including invasive procedures such as coronary angiography and cardiac magnetic resonance tomography, was unremarkable. Slight characteristic facial dysmorphia and transient hypocalcaemia were strongly suggestive of DiGeorge syndrome. The diagnosis was confirmed by genetic testing. Calcium substitution was initiated and no recurrent episodes of syncope or arrhythmic events were reported during 12 months of follow-up.

Discussion

Clinical presentation and time of manifestation of the DiGeorge syndrome varies widely depending on the mutation expression extent. An atypical disease course may delay the diagnosis and appropriate management of affected patients. In this case, confirmation of the diagnosis allowed the initiation of appropriate treatment, reducing the risk for further events. Given that syncope and arrhythmia can be the first and only manifestation of late-onset DiGeorge syndrome, specialists in adult cardiology need to be aware of this presentation.

Successful treatment of severe allergic asthma with omalizumab in a girl with DiGeorge syndrome

DiGeorge syndrome (DGS) is a primary immunodeficiency disease characterized by multiple clinical features, including congenital heart defects, typical facial appearance, hypocalcemia, and immunodeficiency associated to thymic hypoplasia. A subset of patients with DGS may also have contemporary allergic diseases, possibly in the context of T cell dysregulation. Our work presents an unusual case of DGS in coincidence with severe allergic asthma successfully treated by humanized monoclonal anti-IgE antibody, omalizumab. Biological therapy with omalizumab is indicated as an add-on treatment for poorly controlled asthma in patients with severe persistent allergic asthma aged 6 years and above, who meet strict criteria. While data available from clinical trials suggest that omalizumab is generally well-tolerated, a little is known about its efficacy and tolerability in the context of underlying immunodeficiency. We reported for the first time that omalizumab could be safely effective in treatment of severe allergic asthma in patients with DGS, without modification of immunological parameters.

Access to Multidisciplinary Care for Patients With 22q11.2 Deletion Syndrome: Identifying Breakdowns in the Screening Process

The 22q11.2 deletion syndrome affects approximately 1 in 4000 live births and involves cardiac defects, immunodeficiency, and endocrine disruption. The complexity of diagnosis and multifaceted care often leads to fragmented management in the short and long term. With the purpose of developing an effective multidisciplinary program, the authors aimed to identify the deficiencies in current screening and referral processes among the teams required in the care for patients with 22q11.2 deletion syndrome. A retrospective chart review was conducted at our institution between 2001 and 2016. Patients with confirmed 22q11.2 deletion diagnoses between the ages of 0 and 28 were included. A list of 15 relevant specialties that should evaluate patients with 22q11.2 deletion syndrome was created according to established guidelines. Patient medical and demographic information were collected and analyzed. A total of 270 patients were included. Mean age at diagnosis was 3.3 years. On average, patients visited 6 of 15 departments (1-14). Only 8.8% of patients visited >10 specialties. The majority were seen by Cardiology, Allergy and Immunology, Genetics, and Speech (57.4-87.8%). A minority were seen by Hematology and Oncology, Sleep Therapy, and Physical Therapy (13.3-16.3%). Only 34.1% encountered plastic surgery. Negative correlation (-0.128; P = 0.035) was demonstrated between patients' age at diagnosis and number of specialty teams encountered. This study highlights the current underutilization of services required to manage patients with 22q11.2 deletion syndrome. While screening guidelines have been established, implementation can be challenging as it requires efficient care coordination between teams. Moving forward, the authors believe that a multidisciplinary clinical approach to streamline patient care is necessary.

Temporal bone and intracranial abnormalities in syndromic causes of hearing loss: an updated guide

PURPOSE

To describe in detail the temporal bone and brain findings in both common and rare syndromic causes of hearing loss, with the purpose of broadening among radiologists and enhance the current understanding of distinct imaging features in paediatric patients with syndromic hearing loss.

METHODS

A detailed search of electronic databases has been conducted, including PubMed, Ovid Medline, Scopus, Cochrane Library, Google Scholar, National Institute for Health and Care Excellence (NICE), Embase, and PsycINFO.

RESULTS

Syndromic causes of hearing loss are characterised by different and sometimes specific abnormalities in the temporal bone.

CONCLUSION

A complete knowledge of the image findings in the temporal bones, brain, skull and other body regions is critical for the optimal assessment and management of these patients.

Delayed diagnosis of 22q11 deletion syndrome due to late onset hypocalcemia in a 11-year-old girl with imperforated anus

Neonatal hypocalcemia and congenital heart defects has been known as the first clinical manifestation of the chromosome 22q11.2 deletion syndrome (22q11DS). However, because of its wide clinical spectrum, diagnosis of 22q11DS can be delayed in children without classic symptoms. We report the case of a girl with the history of imperforate anus but without neonatal hypocalcemia or major cardiac anomaly, who was diagnosed for 22q11DS at the age of 11 after the onset of overt hypocalcemia. She was born uneventfully from phenotypically normal Korean parents. Imperforate anus and partial cleft palate were found at birth, which were surgically repaired thereafter. There was no history of neonatal hypocalcemia, and karyotyping by GTG banding was normal. At the age of 11, hypocalcemia (serum calcium, 5.0 mg/dL) and decreased parathyroid hormone level (10.8 pg/mL) was noted when she visited our Emergency Department for fever and vomiting. The 22q11DS was suspected because of her mild mental retardation and velopharyngeal insufficiency, and a microdeletion on chromosome 22q11.2 was confirmed by fluorescence in situ hybridization. The 22q11DS should be considered in the differential diagnosis of hypocalcemia at any age because of its wide clinical spectrum.

Modeling human craniofacial disorders in Xenopus

PURPOSE OF REVIEW

Craniofacial disorders are among the most common human birth defects and present an enormous health care and social burden. The development of animal models has been instrumental to investigate fundamental questions in craniofacial biology and this knowledge is critical to understand the etiology and pathogenesis of these disorders.

RECENT FINDINGS

The vast majority of craniofacial disorders arise from abnormal development of the neural crest, a multipotent and migratory cell population. Therefore, defining the pathogenesis of these conditions starts with a deep understanding of the mechanisms that preside over neural crest formation and its role in craniofacial development.

SUMMARY

This review discusses several studies using Xenopus embryos to model human craniofacial conditions, and emphasizes the strength of this system to inform important biological processes as they relate to human craniofacial development and disease.

22q11 Deletion Syndrome and Urogenital Manifestations: A Clinicopathological Case Report

Background

Deletion in the chromosomal region 22q11 results from the abnormal development of the third and fourth pharyngeal pouches during embryonic life and presents an expansive phenotype with more than 180 clinical features described that involve every organ and system.

History and signs

A 23-year-old African woman presented for the first trimester echography, which revealed an isolated anechoic structure suggesting a ureteral dilatation. The suspicion of a malposition of great arteries in the second trimester indicated an amniocentesis leading to a diagnosis of 22q11 deletion.

Outcome

At 32 weeks, the patient was admitted for premature rupture of membranes and gave birth 2 weeks later to a male newborn who presented a respiratory distress syndrome and probably died secondary to a tracheal stenosis. Necropsy revealed typical clinical features of 22q11 deletion associated with left renal agenesis, hypospadias, and penile hypoplasia.

Conclusion

We report a case of 22q11 deletion syndrome with typical clinical features associated with urogenital manifestations suspected at the first trimester ultrasound.

Clinical manifestations and frequency of hypocalcemia in 22q11.2 deletion syndrome

BACKGROUND

This study investigated the evolution of hypocalcemia with age and its associated risk factors in patients with 22q11.2 deletion syndrome (22qDS) and congenital heart defects.

METHOD

A retrospective review of the medical records of 16 22qDS patients (nine female, seven male; age range, 20.5-43 years) was performed. The frequency of hypocalcemia, as well as the clinical course of the disease and the presence of other phenotypes, were investigated.

RESULTS

Ten of the 16 patients (62.5%) had a history of hypocalcemia. Among the 10 patients, the first onset of hypocalcemia occurred in the following developmental periods: neonatal stage, n = 1; early childhood, n = 3; late childhood, n = 2; adolescence, n = 2; and adulthood, n = 2. Neonatal hypocalcemia was observed in one patient, but it was transient. Two patients had sustained hypocalcemia after cardiac surgery. Hypocalcemia in one patient was transient following cardiac surgery, but it recurred during early adulthood. One patient developed hypocalcemia at 43 years of age. Thymus defect tended to be correlated with history of hypocalcemia (P = 0.09). This condition was often transient (60%) and was triggered by physical stress, such as intracardiac surgery.

CONCLUSION

In 22qDS patients, hypocalcemia was often mild and transient during childhood, but it may recur in adulthood. Routine clinical measurement of serum calcium is recommended, particularly in 22qDS patients with thymic defect or in patients who are under physical stress.

"FISHed" out the diagnosis: A case of DiGeorge syndrome

Our patient presented with congenital heart disease (CHD: Tetralogy of Fallot), hypocalcemia, hypoparathyroidism, and facial dysmorphisms. Suspecting DiGeorge syndrome (DGS), a fluorescence in situ hybridization (FISH) analysis for 22q11.2 deletion was made. The child had a hemizygous deletion in the 22q11.2 region, diagnostic of DGS. Unfortunately, the patient succumbed to the heart disease. DGS is the most common microdeletion syndrome, and probably underrecognized due to the varied manifestations. This case stresses the importance of a detailed physical examination and a high index of suspicion for diagnosing this genetic condition. Timely diagnosis can help manage and monitor these patients better and also offer prenatal diagnosis in the next pregnancy.

Congenital Heart Disease as a Warning Sign for the Diagnosis of the 22q11.2 Deletion

Background

To alert for the diagnosis of the 22q11.2 deletion syndrome (22q11.2DS) in patients with congenital heart disease (CHD).

Objective

To describe the main CHDs, as well as phenotypic, metabolic and immunological findings in a series of 60 patients diagnosed with 22q11.2DS.

Methods

The study included 60 patients with 22q11.2DS evaluated between 2007 and 2013 (M:F=1.3, age range 14 days to 20 years and 3 months) at a pediatric reference center for primary immunodeficiencies. The diagnosis was established by detection of the 22q11.2 microdeletion using FISH (n = 18) and/or MLPA (n = 42), in association with clinical and laboratory information. Associated CHDs, progression of phenotypic facial features, hypocalcemia and immunological changes were analyzed.

Results

CHDs were detected in 77% of the patients and the most frequent type was tetralogy of Fallot (38.3%). Surgical correction of CHD was performed in 34 patients. Craniofacial dysmorphisms were detected in 41 patients: elongated face (60%) and/or elongated nose (53.3%), narrow palpebral fissure (50%), dysplastic, overfolded ears (48.3%), thin lips (41.6%), elongated fingers (38.3%) and short stature (36.6%). Hypocalcemia was detected in 64.2% and decreased parathyroid hormone (PTH) level in 25.9%. Decrease in total lymphocytes, CD4 and CD8 counts were present in 40%, 53.3% and 33.3%, respectively. Hypogammaglobulinemia was detected in one patient and decreased concentrations of immunoglobulin M (IgM) in two other patients.

Conclusion

Suspicion for 22q11.2DS should be raised in all patients with CHD associated with hypocalcemia and/or facial dysmorphisms, considering that many of these changes may evolve with age. The 22q11.2 microdeletion should be confirmed by molecular testing in all patients.

Detection of deletions at 7q11.23 in Williams-Beuren syndrome by polymorphic markers

INTRODUCTION

Williams-Beuren syndrome (WBS; OMIM 194050) is caused by a hemizygous contiguous gene microdeletion at 7q11.23. Supravalvular aortic stenosis, mental retardation, overfriendliness, and ocular and renal abnormalities comprise typical symptoms in WBS. Although fluorescence in situ hybridization is widely used for diagnostic confirmation, microsatellite DNA markers are considered highly informative and easily manageable.

OBJECTIVES

This study aimed to test the microsatellite markers for the diagnosis of Williams-Beuren syndrome, to determine the size and parental origin of microdeletion, compare the clinical characteristics between patients with different sizes of the deletion and parental origin.

METHODS

We studied 97 patients with clinical diagnosis of Williams-Beuren syndrome using five microsatellite markers: D7S1870, D7S489, D7S613, D7S2476 and D7S489_A.

RESULTS AND DISCUSSION

Using five markers together, the result was informative in all patients. The most informative marker was D7S1870 (78.4%), followed by D7S613 (75.3%), D7S489 (70.1%) and D7S2476 (62.9%). The microdeletion was present in 84 (86.6%) patients and absent in 13 (13.4%) patients. Maternal deletions were found in 52.4% of patients and paternal deletions in 47.6% of patients. The observed size of deletions was 1.55 Mb in 76/ 84 patients (90.5%) and 1.84 Mb in 8/84 patients (9.5%). SVAS as well as ocular and urinary abnormalities were more frequent in the patients with a deletion. There were no clinical differences in relation to either the size or parental origin of the deletion.

CONCLUSION

Using these five selected microsatellite markers was informative in all patients, thus can be considered an alternative method for molecular diagnosis in Williams-Beuren syndrome.