Syndrome-specific growth charts for 22q11.2 deletion syndrome in Caucasian children

Endocrine manifestations in adults with 22q11.2 deletion syndrome: a retrospective single-center cohort study

INTRODUCTION AND OBJECTIVE

Patients with the 22q11.2 deletion syndrome (22q11DS) frequently display cardiological and psychiatric diseases, but are also at increased risk for endocrine manifestations. The aim of this study was to evaluate the screening, prevalence, and management of hypoparathyroidism and thyroid disease in patients with 22q11DS, to evaluate the metabolic profile, and to compare these results with current literature and guidelines.

DESIGN

We performed a retrospective study of patients with genetically confirmed 22q11DS, followed at the center for human genetics of the University Hospitals Leuven, resulting in a cohort of 75 patients. Medical history, medication, and laboratory results concerning hypoparathyroidism, thyroid dysfunction, and the metabolic profile were collected.

RESULTS

Of the total cohort, 26 patients (35%) had at least one hypocalcaemic episode. During hypocalcaemia, parathyroid hormone (PTH) was measured in only 12 patients with 11 having normal or low PTH, confirming a diagnosis of hypoparathyroidism. Recurrent episodes of hypocalcaemia occurred in seventeen patients (23%). Adherence to the guidelines was low, with 13% of patients having a yearly serum calcium evaluation, 12% receiving daily calcium supplements, and 20% receiving non-active vitamin D. Hypothyroidism was present in 31 patients (44%) and hyperthyroidism in 6 patients (8%). Information on body mass index (BMI) was available in 52 patients (69%), of which 38% were obese (BMI ≥ 30 kg/m2).

CONCLUSION

Hypoparathyroidism, hypothyroidism, and obesity are common endocrine manifestations in patients with 22q11DS but are probably underdiagnosed and undertreated, indicating the need for multidisciplinary follow-up including an endocrinologist.

An Endocrinological Perspective on 22q11.2 Deletion Syndrome: A Single-center Experience

Objective

22q11.2 deletion syndrome (22q11.2 DS) is the most common chromosomal microdeletion disorder. Associated problems in 22q11.2 DS may include cardiac abnormalities, immune dysfunction, facial dysmorphism, with endocrine, genitourinary and gastrointestinal problems, and developmental delay. The aim of this study was to evaluate and present all endocrinological findings of patients with 22q11.2 DS from a single center.

Methods

All participants had confirmed 22q11.2 DS by fluorescence in situ hybridization with hypoparathyroidism. Data were retrieved by retrospective review of patient records.

Results

A total of 17 patients were reviewed. On physical examination, all patients had similar dysmorphic features. The median age at diagnosis was 45 days (1 day-13 years). Most cases (64.7%, 11/17) were diagnosed with hypoparathyroidism incidentally after routine tests. At the time of diagnosis, mean calcium was 7.04±0.80 mg/dL, phosphorus was 6.2±1.1 mg/dL, and median parathyroid hormone (PTH) was 11.5 (3.7-47.6) ng/L. Transient hypoparathyroidism was detected in five cases (29.4%). There was no significant difference between patients with permanent or transient hypoparathyroidism regarding gender, age at diagnosis, calcium, phosphorus, and PTH levels. However, vitamin D levels were significantly lower in the transient group (p=0.036). During follow-up, short stature, obesity, and type 2 diabetes mellitus were absent. Thyroid autoantibodies were detected in two patients with normal thyroid function tests. Despite there being no pathological short stature, final stature was shorter than the general population (mean height standard deviation score: -0.94±0.83).

Conclusion

Hypocalcemia may be detected during acute illness in some cases where hypocalcemia appears at later ages. There was no significant difference between permanent and transient hypoparathyroidism cases in terms of PTH level. Recognition of the more specific facial findings is important to trigger investigation of genetic variants, additional anomalies, and for follow-up.

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

This review aimed to update the clinical practice guidelines for managing children and adolescents with 22q11.2 deletion syndrome (22q11.2DS). The 22q11.2 Society, the international scientific organization studying chromosome 22q11.2 differences and related conditions, recruited expert clinicians worldwide to revise the original 2011 pediatric clinical practice guidelines in a stepwise process: (1) a systematic literature search (1992-2021), (2) study selection and data extraction by clinical experts from 9 different countries, covering 24 subspecialties, and (3) creation of a draft consensus document based on the literature and expert opinion, which was further shaped by survey results from family support organizations regarding perceived needs. Of 2441 22q11.2DS-relevant publications initially identified, 2344 received full-text reviews, including 1545 meeting criteria for potential relevance to clinical care of children and adolescents. Informed by the available literature, recommendations were formulated. Given evidence base limitations, multidisciplinary recommendations represent consensus statements of good practice for this evolving field. These recommendations provide contemporary guidance for evaluation, surveillance, and management of the many 22q11.2DS-associated physical, cognitive, behavioral, and psychiatric morbidities while addressing important genetic counseling and psychosocial issues.

Adult Height, 22q11.2 Deletion Extent, and Short Stature in 22q11.2 Deletion Syndrome

The 22q11.2 deletion syndrome (22q11.2DS) manifests as a wide range of medical conditions across a number of systems. Pediatric growth deficiency with some catch-up growth is reported, but there are few studies of final adult height. We aimed to investigate how final adult height in 22q11.2DS compared with general population norms, and to examine predictors of short stature in in a cohort of 397 adults with 22q11.2DS (aged 17.6–76.3 years) with confirmed typical 22q11.2 microdeletion (overlapping the LCR22A to LCR22B region). We defined short stature as <3rd percentile using population norms. For the subset (n = 314, 79.1%) with 22q11.2 deletion extent, we used a binomial logistic regression model to predict short stature in 22q11.2DS, accounting for effects of sex, age, ancestry, major congenital heart disease (CHD), moderate-to-severe intellectual disability (ID), and 22q11.2 deletion extent. Adult height in 22q11.2DS showed a normal distribution but with a shift to the left, compared with population norms. Those with short stature represented 22.7% of the 22q11.2DS sample, 7.6-fold greater than population expectations (p < 0.0001). In the regression model, moderate-to-severe ID, major CHD, and the common LCR22A-LCR22D (A-D) deletion were significant independent risk factors for short stature while accounting for other factors (model p = 0.0004). The results suggest that the 22q11.2 microdeletion has a significant effect on final adult height distribution, and on short stature with effects appearing to arise from reduced gene dosage involving both the proximal and distal sub-regions of the A-D region. Future studies involving larger sample sizes with proximal nested 22q11.2 deletions, longitudinal lifetime data, parental heights, and genotype data will be valuable.

Endocrine and Growth Disorders in Taiwanese Children With 22q11.2 Deletion Syndrome

BACKGROUND

Endocrine disorders are common in patients with 22q11.2 deletion syndrome (22q11.2DS). This study aimed to elucidate the clinical manifestations of endocrine disorders, including parathyroid, thyroid and growth disorders, in Taiwanese patients with 22q11.2DS.

METHODS

From 1994 to 2020, the medical records of 138 patients with 22q11.2DS diagnosed at a tertiary referral medical center in Taiwan were thoroughly reviewed retrospectively.

RESULTS

Hypocalcemia was detected in 57 of 135 patients (42%); 33 of 104 patients (32%) had hypoparathyroidism, and in 87% of them, hypocalcemia was detected before the age of one. Most patients had precipitating stressors during symptomatic hypocalcemic episodes. Eighteen of 29 patients had overt hypoparathyroidism at the last visit: 11 had persistent hypoparathyroidism and the other seven had recurrent hypoparathyroidism. Four of 84 patients had thyroid disorders, including thyroid developmental anomalies in two, dyshormonogenesis in one and Graves' disease in one. Fifty of 126 patients (40%) had short stature. Age (odds ratio (OR) 0.91; 95% confidence interval (CI) 0.86-0.96; P<0.001) and airway anomalies (OR 2.75; 95% CI 1.04-7.31; P<0.05) were significant risk factors for short stature in multivariate logistic regression model. Twenty-eight of the 30 patients with airway anomalies were associated with severe congenital heart disease. Adult height standard deviation score (SDS) in 19 patients was significantly lower than target height SDS (-1.15 ± 0.90 vs -0.08 ± 0.65, P<0.001).

CONCLUSIONS

Hypoparathyroidism is a common endocrine disorder in patients with 22q11.2DS. It is prudent to assess parathyroid function at diagnosis and during follow-up, especially in the presence of stress, to prevent symptomatic hypocalcemia. Although thyroid disorders are not so common as hypoparathyroidism, screening of thyroid dysfunction is justified in these patients. Patients with 22q11.2DS demonstrate a retarded growth pattern with a tendency of catch-up and regular monitoring of growth is indicated.

Opposing white matter microstructure abnormalities in 22q11.2 deletion and duplication carriers

Deletions and duplications at the 22q11.2 locus are associated with significant neurodevelopmental and psychiatric morbidity. Previous diffusion-weighted magnetic resonance imaging (MRI) studies in 22q11.2 deletion carriers (22q-del) found nonspecific white matter (WM) abnormalities, characterized by higher fractional anisotropy. Here, utilizing novel imaging and processing methods that allow separation of signal contribution from different tissue properties, we investigate whether higher anisotropy is driven by (1) extracellular changes, (2) selective degeneration of secondary fibers, or (3) volumetric differences. We further, for the first time, investigate WM microstructure in 22q11.2 duplication carriers (22q-dup). Multi-shell diffusion-weighted images were acquired from 26 22q-del, 19 22q-dup, and 18 healthy individuals (HC). Images were fitted with the free-water model to estimate anisotropy following extracellular free-water elimination and with the novel BedpostX model to estimate fractional volumes of primary and secondary fiber populations. Outcome measures were compared between groups, with and without correction for WM and cerebrospinal fluid (CSF) volumes. In 22q-del, anisotropy following free-water elimination remained significantly higher compared with controls. BedpostX did not identify selective secondary fiber degeneration. Higher anisotropy diminished when correcting for the higher CSF and lower WM volumes. In contrast, 22q-dup had lower anisotropy and greater extracellular space than HC, not influenced by macrostructural volumes. Our findings demonstrate opposing effects of reciprocal 22q11.2 copy-number variation on WM, which may arise from distinct pathologies. In 22q-del, microstructural abnormalities may be secondary to enlarged CSF space and more densely packed WM. In 22q-dup, we see evidence for demyelination similar to what is commonly observed in neuropsychiatric disorders.

Relationship between parent-reported gastrointestinal symptoms, sleep problems, autism spectrum disorder symptoms, and behavior problems in children and adolescents with 22q11.2 deletion syndrome

BACKGROUND

22q11.2 deletion syndrome (22q) is a chromosome disorder, where a segment of chromosome 22, located at q11.2, is missing. This study aims to investigate the relationship between a number of parent-reported comorbid conditions including gastrointestinal symptoms, sleep problems, autism spectrum disorder (ASD) symptoms and behavior problems in children and adolescents with 22q deletion syndrome.

METHOD

The Gastrointestinal Symptom Inventory, Children's Sleep Habits Questionnaire, Behavior Problem Inventory-Short Form and the Social Communication Questionnaire were completed by parents of 149 children and adolescents aged 3-18 years with a diagnosis of 22q.

RESULTS

A series of correlations and hierarchical multiple regressions were conducted to examine the relationships between GI symptoms, sleep problems and behavior problems in children and adolescents with 22q deletion syndrome. A significant moderate relationship was found between GI symptoms and sleep problems. Gender and ASD symptoms predicted GI symptoms. Significant small relationships were found between GI symptoms and self-injurious behavior. Significant small to moderate relationships were found between sleep problems and self-injurious behavior, aggressive/destructive behavior, and sterotyped behavior. Sleep problems predicted challenging behavior.

CONCLUSIONS

This research demonstrated the importance of studying the relationship between comorbidities, including gastrointestinal symptoms, sleep problems, and behavior problems and how they shape the phenotype of 22q deletion syndrome.

Ontogeny of the facial phenotypic variability in Mexican patients with 22q11.2 deletion syndrome

Background

22q11.2 deletion syndrome is a medical condition that results from genomic loss at chromosome 22. Affected patients exhibit large variability that ranges from a severe condition to mild symptoms. In addition, the spectrum of clinical features differs among populations and even within family members. The facial features related to this syndrome are not an exception, and although part of its variation arises through development, few studies address this topic in order to understand the intra and inter-population heterogeneities. Here, we analyze the ontogenetic dynamics of facial morphology of Mexican patients with del22q11.2 syndrome.

Methods

Frontal facial photographs of 37 patients (mean age = 7.65 ± 4.21 SE) with del22q11.2DS and 200 control subjects (mean age = 7.69 ± 4.26 SE) were analyzed using geometric morphometric methods. Overall mean shape and size differences between patients and controls were analyzed, as well as differences in ontogenetic trajectories (i.e. development, growth, and allometry).

Results

We found that Mexican patients show typical traits that have been reported for the Caucasian population. Additionally, there were significant differences between groups in the facial shape and size when all the ontogenetic stages were considered together and, along ontogeny. The developmental and allometric trajectories of patients and controls were similar, but they differed in allometric scaling. Finally, patients and controls showed different growth trajectories.

Conclusion

The results suggest that the typical face of patients with del22q11.2DS is established prenatally; nonetheless, the postnatal ontogeny could influence the dysmorphology and its variability through size-related changes.

Speech-Language Disorders in 22q11.2 Deletion Syndrome: Best Practices for Diagnosis and Management

Purpose Speech and language disorders are hallmark features of 22q11.2 deletion syndrome (22qDS). Learning disabilities, cognitive deficits, palate abnormalities, velopharyngeal dysfunction, behavioral differences, and various medical and psychiatric conditions are also major features of this syndrome. The goal of this document is to summarize the state of the art of current clinical and scientific knowledge regarding 22qDS for speech-language pathologists (SLPs) and provide recommendations for clinical management. Method Best practices for management of individuals with 22qDS were developed by consensus of an expert international group of SLPs and researchers with expertise in 22qDS. These care recommendations are based on the authors' research, clinical experience, and literature review. Results This document describes the features of 22qDS as well as evaluation procedures, treatment protocols, and associated management recommendations for SLPs for the often complex communication disorders present in this population. Conclusion Early diagnosis and appropriate management of speech-language disorders in 22qDS is essential to optimize outcomes and to minimize the long-term effects of communication impairments. Knowledge of this diagnosis also allows anticipatory care and guidance regarding associated features for families, health care, and educational professionals.

Growth hormone therapy in children; research and practice - A review

Short stature remains the most common reason for referral to a pediatric Endocrinologist and its management remains a challenge. One of the main controversies is the diagnosis of idiopathic short stature and the role of new technologies for genetic investigation of children with inadequate growth. Complexities in management of children with short stature includes selection of who should receive interventions such as recombinant human growth hormone, and how should this agent dose be adjusted during treatment. Should anthropometrical data be the primary determinant or should biochemical and genetic data be used to improve growth response and safety? Furthermore, what is considered a suboptimal response to growth hormone therapy and how should this be managed? Treatment of children with short stature remains a "hot" topic and more data is needed in several areas. These issues are reviewed in this paper.

What is new with 22q? An update from the 22q and You Center at the Children's Hospital of Philadelphia

22q11.2 deletion syndrome (22q11.2DS) is a disorder caused by recurrent, chromosome-specific, low copy repeat (LCR)-mediated copy-number losses of chromosome 22q11. The Children's Hospital of Philadelphia has been involved in the clinical care of individuals with what is now known as 22q11.2DS since our initial report of the association with DiGeorge syndrome in 1982. We reviewed the medical records on our continuously growing longitudinal cohort of 1,421 patients with molecularly confirmed 22q11.2DS from 1992 to 2018. Most individuals are Caucasian and older than 8 years. The mean age at diagnosis was 3.9 years. The majority of patients (85%) had typical LCR22A-LCR22D deletions, and only 7% of these typical deletions were inherited from a parent harboring the deletion constitutionally. However, 6% of individuals harbored other nested deletions that would not be identified by traditional 22q11.2 FISH, thus requiring an orthogonal technology to diagnose. Major medical problems included immune dysfunction or allergies (77%), palatal abnormalities (67%), congenital heart disease (64%), gastrointestinal difficulties (65%), endocrine dysfunction (>50%), scoliosis (50%), renal anomalies (16%), and airway abnormalities. Median full-scale intelligence quotient was 76, with no significant difference between individuals with and without congenital heart disease or hypocalcemia. Characteristic dysmorphic facial features were present in most individuals, but dermatoglyphic patterns of our cohort are similar to normal controls. This is the largest longitudinal study of patients with 22q11.2DS, helping to further describe the condition and aid in diagnosis and management. Further surveillance will likely elucidate additional clinically relevant findings as they age.

The impact of hypocalcemia on full scale IQ in patients with 22q11.2 deletion syndrome

Hypocalcemia has been reported in ~50% of patients 22q11.2DS and calcium regulation is known to play a role in neuronal development and synaptic plasticity. Because calcium ions play a role in neuronal function and development, we hypothesized that hypocalcemia would be associated with adverse effects on full scale IQ index (FSIQ) in patients with 22q11.2DS. A retrospective chart review cataloguing the presence or absence of hypocalcemia in 1073 subjects with a laboratory confirmed chromosome 22q11.2 deletion evaluated at the Children's Hospital of Philadelphia was conducted. 852/1073 patients had an endocrinology evaluation with laboratory confirmed calcium levels. 466/852 (54.7%) had a diagnosis of hypocalcemia. 265/1073 subjects ranging from 0 to 51 years of age had both calcium levels measured and a neuropsychological evaluation yielding a FSIQ. The mean FSIQ for 146/265 patients with hypocalcemia was 77.09 (SD = 13.56) and the mean FSIQ for 119/265 patients with normocalcemia was 77.27 (SD = 14.25). The distribution of patients with intellectual disability (ID) (FSIQ<69), borderline IQ (FSIQ 70-79), and average IQ (FSIQ>80) between the hypocalcemic and normocalcemic groups was not statistically significant (χ2 = 0.2676, p = 0.8748). Neonatal hypocalcemic seizures were not found to be associated with ID. We found no difference in FSIQ between the hypocalcemic and non-hypocalcemic patients with 22q11.2DS. As our findings differ from a previous report in adult subjects, we speculate that this may reflect a potential benefit from early treatment of hypocalcemia and may support early 22q11.2 deletion detection in order to offer prompt diagnosis and subsequent treatment of hypocalcemia.

An Update on Common Chromosome Microdeletion and Microduplication Syndromes

This review summarizes common microdeletion and microduplication syndromes and highlights important updates in patient-care needs for people with these conditions (22q11.2, 7q11.23, 17p11.2, and 16p11.2). These conditions are in chromosomal "hotspots" and have an estimated prevalence of 1 in 1,000 to 1 in 25,000. Some conditions have possible increased or decreased genetic risk of schizophrenia (22q11.2 deletion and duplication), or risk of aortic dilation (7q11.23 duplication) versus aortic stenosis (7q11.23 deletion). Many of these conditions are associated with developmental delay, autism, and/or multiple congenital anomalies and would not be detected with a karyotype. Chromosomal microarray analysis will detect all these conditions with a single screening test, allowing for the appropriate diagnosis and management of these patients. [Pediatr Ann. 2018;47(5):e198-e203.].

Recurrent reciprocal copy number variants: Roles and rules in neurodevelopmental disorders

Deletions and duplications, called reciprocal CNVs when they occur at the same locus, are implicated in neurodevelopmental phenotypes ranging from morphological to behavioral. In this article, we propose three models of how differences in gene expression in deletion and duplication genotypes may result in deleterious phenotypes. To explore these models, we use examples of the similarities and differences in clinical phenotypes of five reciprocal CNVs known to cause neurodevelopmental disorders: 1q21.1, 7q11.23, 15q13.3, 16p11.2, and 22q11.2. These models and examples may inform some insights into better understanding of gene-phenotype relationships. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 519-530, 2018.

CNV-association meta-analysis in 191,161 European adults reveals new loci associated with anthropometric traits

There are few examples of robust associations between rare copy number variants (CNVs) and complex continuous human traits. Here we present a large-scale CNV association meta-analysis on anthropometric traits in up to 191,161 adult samples from 26 cohorts. The study reveals five CNV associations at 1q21.1, 3q29, 7q11.23, 11p14.2, and 18q21.32 and confirms two known loci at 16p11.2 and 22q11.21, implicating at least one anthropometric trait. The discovered CNVs are recurrent and rare (0.01–0.2%), with large effects on height (>2.4 cm), weight (>5 kg), and body mass index (BMI) (>3.5 kg/m²). Burden analysis shows a 0.41 cm decrease in height, a 0.003 increase in waist-to-hip ratio and increase in BMI by 0.14 kg/m² for each Mb of total deletion burden (P = 2.5 × 10⁻¹⁰, 6.0 × 10⁻⁵, and 2.9 × 10⁻³). Our study provides evidence that the same genes (e.g., MC4R, FIBIN, and FMO5) harbor both common and rare variants affecting body size and that anthropometric traits share genetic loci with developmental and psychiatric disorders.

Individual SNPs have small effects on anthropometric traits, yet the impact of CNVs has remained largely unknown. Here, Kutalik and co-workers perform a large-scale genome-wide meta-analysis of structural variation and find rare CNVs associated with height, weight and BMI with large effect sizes.

Growth charts for Australian children with achondroplasia

Achondroplasia is an autosomal dominant disorder, the most common genetic cause of short stature in humans. Reference curves for head circumference, weight, height, and BMI are needed in clinical practice but none exist for the Australian population. This study aimed to produce head circumference, height, weight, and BMI reference percentile curves for Australian children and adolescents with achondroplasia. Measurements of head circumference, height and weight taken at clinical visits were retrospectively extracted from the electronic medical record. Age was corrected for prematurity. Patients were excluded from head circumference analysis if they had significant neurosurgical complications and from the weight and BMI analysis when they had a clinical diagnosis of overweight. Measurements were available on 138 individuals (69 males and 69 females) taken between 1970 and 2015, with over 50% collected since 2005. A total of 3,352 data points were available. The LMS method was used to produce growth charts with estimated centiles (10, 25, 50, 75, and 90th) separately for males and females. For females birth weight was 3 kg (2.5-3.5 kg), birth length 48 cm (44-50 cm) and head circumference 37.5 cm (36-39 cm), adult height was 125 cm (116-132 cm), weight 42 kg (34-54 kg), and head circumference 58 cm (55.5-60.5 cm) all 50th centile (10-90th). For males birth weight was 3.5 kg (3-4 kg), length 49 cm (46-52 cm) and head circumference 38.5 cm (36-41 cm), adult height was 134 cm (125-141 cm), weight 41 kg (24.5-57 kg) and head circumference 61 cm (58-64 cm). The curves are similar to previously published reference data from the USA and have expected population wide variation from curves from an Argentinian population. Despite limitations of our curves for adolescents (12 years and older) due to data paucity, these Australian growth charts for children and adolescents with achondroplasia will be a useful reference in clinical practice.

Growth characteristics and endocrine abnormalities in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) has a wide range of clinical features including endocrine abnormalities. We aimed to characterize growth patterns, hypoparathyroidism, and thyroid dysfunction of individuals with 22q11.2DS. Anthropometric and laboratory measurements were obtained from the charts of 48 individuals (males=28, 8.0±6.8 visits/participant) followed at a national 22q11.2DS clinic between 2009 and 2016. Age at diagnosis was 4.3±4.9 years and age at last evaluation 11.2±7.2 years. Median height-SDS was negative at all ages. Height-SDS at last visit was correlated to the midparental height-SDS (r=0.52 P=0.002). Yet, participants did not reach their target height, with a difference of 1.06±1.07 SD (P <0.0001). Height-SDS at last visit of participants with a heart defect was lower compared to participants with a normal heart (-1.5±1.4 vs. -0.6±0.8, P=0.036), with lower height-SDS in the subgroup of participants with severe heart defects (-2.1±1.6, P=0.009). Mean IGF1-SDS was low (-0.99±1.68) but was not correlated with height-SDS. Thirteen patients (27%) had hypoparathyroidism: 10 presented during infancy and 3 during adolescence. Five patients (10.4%, female=4) had thyroid abnormalities. In conclusions, individuals with 22q11.2 DS have a distinct growth pattern consisting of growth restriction at all ages, resulting in final adult height in the low-normal range. Hypoparathyroidism is common and may present during the neonatal period as well as later in life. Thyroid abnormalities may present during childhood, adolescence, or adulthood.

Obesity in adults with 22q11.2 deletion syndrome

PURPOSE

To characterize the prevalence of and contributing factors to adult obesity in the most common recurrent copy-number variation (CNV), 22q11.2 deletion, given that other rare CNVs are known to have obesity phenotypes.

METHODS

In 207 adults with 22q11.2 deletion syndrome (22q11.2DS), we used available height and weight measurements to calculate body mass index (BMI) and recorded associated factors that could play a role in obesity. We used the maximum BMI per subject and logistic regression to test a model predicting obesity class.

RESULTS

The prevalence of obesity (BMI ≥30) in 22q11.2DS (n = 90, 43.5%; at median age of 26.7 years) was significantly greater than for Canadian norms (odds ratio (OR) 2.30, 95% confidence interval (CI) = 1.74-3.02, P < 0.0001), even after excluding individuals with a history of antipsychotic use. The regression model was significant (P < 0.0001). Psychotropic medication use and age, but not sex or presence of intellectual disability, were associated with higher obesity level. Ten (4.8%) individuals were diagnosed with type 2 diabetes at a median age of 39.5 years; the prevalence was higher in those with obesity (P < 0.01).

CONCLUSION

The results suggest that adult obesity is related to the 22q11.2 deletion. The findings expand the potential genetic causes of obesity and have important implications for management of 22q11.2DS.Genet Med 19 2, 204-208.

Congenital Heart Defects and Measures of Fetal Growth in Newborns with Down Syndrome or 22q11.2 Deletion Syndrome

OBJECTIVES

To estimate the association between congenital heart defects (CHD) and indices of fetal growth in Down and 22q11.2 deletion syndromes.

STUDY DESIGN

We established 2 Danish nationwide cohorts of newborn singletons with either Down syndrome (n = 670) or 22q11.2 deletion syndrome (n = 155), born 1997-2011. In both cohorts, we analyzed the association between CHD, CHD severity, and indices of fetal growth by multivariable linear regression adjusted for potential confounders. We report mean differences in gestational age specific z-scores compared with newborns without CHD.

RESULTS

Down syndrome and 22q11.2 deletion syndrome were both associated with lower mean birth weight and head circumference z-scores. We found no association between CHD or CHD severity and indices of fetal growth. In Down syndrome, the association between any CHD and the mean difference in head circumference z-score was 0.03 (95% CI -0.12, 0.18), and the estimate regarding birth weight z-score was 0.09 (95% CI -0.08, 0.25). The corresponding estimates in 22q11.2 deletion syndrome were 0.00 (95% CI -0.33, 0.32) and -0.09 (95% CI -0.45, 0.26).

CONCLUSIONS

We found no association between CHD and fetal growth measures in newborns with Down syndrome or 22q11.2 deletion syndrome. Thus, in certain subtypes of CHD, the contribution of genetic factors to prenatal growth impairment may be more important than circulatory disturbances.

Failure to thrive as presentation in a patient with 22q11.2 microdeletion

BACKGROUND

Abnormalities of chromosome 22q11, including deletions and translocations, have been described in association with different birth defects and malformations occurring in many combinations and degrees of severity.

CASE PRESENTATION

We describe the case of an 8 month-old infant with no dysmorphic signs who showed progressive postnatal growth failure and no chronic systemic diseases. We found a 22q11.2 microdeletion, inherited from the mother, suggesting the diagnosis of DiGeorge syndrome. The patient had an isolated growth hormone (GH) deficiency and a significant increase in linear growth during the first and the second year of GH therapy, and a recovery of weight was shown.

CONCLUSIONS

Sometimes, in infants with growth failure a genetic analysis is strongly suggested, since chromosomal abnormalities may be present.

22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11.2DS) is the most common chromosomal microdeletion disorder, estimated to result mainly from de novo non-homologous meiotic recombination events occurring in approximately 1 in every 1,000 fetuses. The first description in the English language of the constellation of findings now known to be due to this chromosomal difference was made in the 1960s in children with DiGeorge syndrome, who presented with the clinical triad of immunodeficiency, hypoparathyroidism and congenital heart disease. The syndrome is now known to have a heterogeneous presentation that includes multiple additional congenital anomalies and later-onset conditions, such as palatal, gastrointestinal and renal abnormalities, autoimmune disease, variable cognitive delays, behavioural phenotypes and psychiatric illness - all far extending the original description of DiGeorge syndrome. Management requires a multidisciplinary approach involving paediatrics, general medicine, surgery, psychiatry, psychology, interventional therapies (physical, occupational, speech, language and behavioural) and genetic counselling. Although common, lack of recognition of the condition and/or lack of familiarity with genetic testing methods, together with the wide variability of clinical presentation, delays diagnosis. Early diagnosis, preferably prenatally or neonatally, could improve outcomes, thus stressing the importance of universal screening. Equally important, 22q11.2DS has become a model for understanding rare and frequent congenital anomalies, medical conditions, psychiatric and developmental disorders, and may provide a platform to better understand these disorders while affording opportunities for translational strategies across the lifespan for both patients with 22q11.2DS and those with these associated features in the general population.

Velocardiofacial syndrome in Mexican patients: Unusually high prevalence of congenital heart disease

INTRODUCTION

Velocardiofacial syndrome (VCFS) is the most common microdeletion syndrome with an incidence of 1:4000 live births. Its phenotype is highly variable with facial, velopharyngeal, cardiac, endocrine, immunologic and psychiatric abnormalities. It is caused by a microdeletion in chromosome 22q11.2.

OBJECTIVES

We present 7 years of experience evaluating patients with VCFS regarding their main clinical characteristics.

MATERIAL AND METHODS

The patients included were multidisciplinary evaluated and had a positive FISH analysis for del22q11.2.

RESULTS

A total of 62 patients were assessed, a 34 female/28 male ratio was observed with ages ranging from 9 days to 16 years, all but one patient had typical facial features. A diagnosis of congenital heart disease was established in 97% of the patients; other clinical characteristics were identified with different percentages such as cleft palate, and hypocalcaemia. Three cases had a familial presentation.

DISCUSSION

While the clinical findings of this study were in general terms in keeping with the literature, it is interesting the unexpectedly high percentage of congenital heart disease identified in Mexican children with VCFS that also was the main cause for clinical referral.

Cognitive decline preceding the onset of psychosis in patients with 22q11.2 deletion syndrome

IMPORTANCE

Patients with 22q11.2 deletion syndrome (22q11DS) have an elevated (25%) risk of developing schizophrenia. Recent reports have suggested that a subgroup of children with 22q11DS display a substantial decline in cognitive abilities starting at a young age.

OBJECTIVE

To determine whether early cognitive decline is associated with risk of psychotic disorder in 22q11DS.

DESIGN, SETTING, AND PARTICIPANTS

Prospective longitudinal cohort study. As part of an international research consortium initiative, we used the largest data set of intelligence (IQ) measurements in patients with 22q11DS reported to date to investigate longitudinal IQ trajectories and the risk of subsequent psychotic illness. A total of 829 patients with a confirmed hemizygous 22q11.2 deletion, recruited through 12 international clinical research sites, were included. Both psychiatric assessments and longitudinal IQ measurements were available for a subset of 411 patients (388 with ≥1 assessment at age 8-24 years).

MAIN OUTCOMES AND MEASURES

Diagnosis of a psychotic disorder, initial IQ, longitudinal IQ trajectory, and timing of the last psychiatric assessment with respect to the last IQ test.

RESULTS

Among 411 patients with 22q11DS, 55 (13.4%) were diagnosed as having a psychotic disorder. The mean (SD) age at the most recent psychiatric assessment was 16.1 (6.2) years. The mean (SD) full-scale IQ at first cognitive assessment was lower in patients who developed a psychotic disorder (65.5 [12.0]) compared with those without a psychotic disorder (74.0 [14.0]). On average, children with 22q11DS showed a mild decline in IQ (full-scale IQ, 7.04 points) with increasing age, particularly in the domain of verbal IQ (9.02 points). In those who developed psychotic illness, this decline was significantly steeper (P < .001). Those with a negative deviation from the average cognitive trajectory observed in 22q11DS were at significantly increased risk for the development of a psychotic disorder (odds ratio = 2.49; 95% CI, 1.24-5.00; P = .01). The divergence of verbal IQ trajectories between those who subsequently developed a psychotic disorder and those who did not was distinguishable from age 11 years onward.

CONCLUSIONS AND RELEVANCE

In 22q11DS, early cognitive decline is a robust indicator of the risk of developing a psychotic illness. These findings mirror those observed in idiopathic schizophrenia. The results provide further support for investigations of 22q11DS as a genetic model for elucidating neurobiological mechanisms underlying the development of psychosis.

Towards a safety net for management of 22q11.2 deletion syndrome: guidelines for our times

The commonest autosomal deletion, 22q11.2 deletion syndrome (22q11DS) is a multisystem disorder varying greatly in severity and age of identification between affected individuals. Holistic care is best served by a multidisciplinary team, with an anticipatory approach. Priorities tend to change with age, from feeding difficulties, infections and surgery of congenital abnormalities particularly of the heart and velopharynx in infancy and early childhood to longer-term communication, learning, behavioural and mental health difficulties best served by evaluation at intervals to consider and initiate management. Regular monitoring of growth, endocrine status, haematological and immune function to enable early intervention helps in maintaining health.

CONCLUSION

Guidelines to best practice management of 22q11DS based on a literature review and consensus have been developed by a national group of professionals with consideration of the limitations of available medical and educational resources.