Noninvasive screening by cell-free DNA for 22q11.2 deletion: Benefits, limitations, and challenges.

Cell-free DNA (cfDNA) testing for fetal aneuploidy is one of the most important technical advances in prenatal care. Additional chromosome targets beyond common aneuploidies, including the 22q11.2 microdeletion, are now available because of this clinical testing technology. While there are numerous potential benefits, 22q11.2 microdeletion screening using cfDNA testing also presents significant limitations and pitfalls. Practitioners who are offering this test should provide comprehensive pretest and posttest prenatal counselling. The discussion should include the possibility of an absence of a result, as well as the risk of possible discordance between cfDNA screening results and the actual fetal genetic chromosomal constitution. The goal of this review is to provide an overview of the cfDNA testing technologies for 22q11.2 microdeletions screening, describe the current state of test validation and clinical experience, review "no results" and discordant findings based on differing technologies, and discuss management options.

Young Adult Outcomes for Children With 22q11 Deletion Syndrome and Comorbid ADHD.

Background: 22q11.2 deletion syndrome (22q11DS) is a common microdeletion syndrome associated with a variety of negative health, cognitive, emotional, and behavioral outcomes. 22q11DS is comorbid with many psychiatric disorders including attention-deficit/hyperactivity disorder (ADHD). The current study aimed to investigate the cognitive, behavioral, and functional outcomes that a childhood ADHD diagnosis predicts to in adulthood. Methods: This longitudinal study followed 52 individuals with 22q11DS over 9 years. Childhood ADHD was operationalized both categorically (Diagnostic and statistical manual - 4th edition (DSM-IV) ADHD diagnoses) and dimensionally (inattentive and hyperactive-impulsive symptoms) and was tested as predictors of young adult outcomes. Results: As young adults, children with 22q11DS + baseline ADHD had more parent-reported executive dysfunction and lower levels of clinician-rated overall functioning than those with 22q11DS yet without ADHD. Dimensional symptoms of ADHD in childhood did not predict young adult outcomes. No self-report differences emerged between those with and without baseline ADHD. The majority (82.4%) of individuals with 22q11DS + baseline ADHD were never treated with an ADHD medication. Conclusions: A categorical diagnosis of ADHD in childhood predicted a greater variety of worse outcomes than dimensional levels of ADHD symptoms. Despite the significant impact of comorbid ADHD in 22q11DS, evidence-based treatment rates were low.

Characteristics of prenatally detected right aortic arch cases in a single institution.

This study aimed to elucidate the diagnostic process, the associated anomalies and the perinatal outcomes of right aortic arch (RAA) in a group of low-risk patients. The obstetric imaging database and digital patient files were reviewed between January 2015 and June 2016. There were 12 RAA cases detected prenatally. Seven foetuses had an aberrant left subclavian artery and one foetus had mirror image branching. The prevalence of RAA was 1.8 in 1000. Invasive prenatal diagnosis was offered to patients and seven tests were performed. There was one associated cardiac anomaly (8.3%) and one extra-cardiac anomaly (8.3%) in the same foetus which cordocentesis revealed trisomy 21. There were also two 22q11.2 microdeletion cases with isolated RAA with aberrant left subclavian arteries. All patients have given live births except one patient has chosen a termination of pregnancy for 22q11.2 microdeletion. The median follow-up time of the newborns was 21 months. None of the babies required surgery for RAA during follow-up. All the babies are alive, except for the one with trisomy 21, who dead at 5 months due to the surgical complications of an oesophageal atresia operation. Patients with an RAA foetus should be offered for foetal karyotyping and analysis for 22q11.2 microdeletion. When isolated, RAA has usually a good prognosis and rarely requires cardiac surgery. Impact Statement What is already known on this subject? Prenatal diagnosis of RAA should prompt a detailed cardiac and extra-cardiac ultrasound examination. When isolated, RAA is associated with 22q11 deletion and aneuploidies in 4.6% and 5.1%, of cases respectively. What the results of this study add? Our study showed that 28.5% of isolated RAA cases are associated with 22q11.2 microdeletion. Cardiac surgery is rarely required when RAA is an isolated anomaly. What the implications are of these findings for clinical practice and/or further research? Invasive prenatal testing for karyotypes and 22q11.2 microdeletion should be offered to patients with RAA, even in the case of an isolated one. Further larger studies are needed to confirm this finding.

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.

Confined placental mosaicism for 22q11.2 deletion as the etiology for discordant positive NIPT results.

22q11.2 deletion, the most common microdeletion syndrome within the general population, is estimated to have a prevalence of 1 in 3000 to 6000. Non-invasive prenatal testing has recently expanded to include screening for several microdeletions including 22q11.2. Given the expansion of prenatal screening options to include microdeletions, it is important to understand the limits of this technology and the variety of reasons that a discordant positive result can occur. Here, we describe a case of a pregnant woman who received a positive non-invasive prenatal maternal plasma screen for 22q11.2 deletion. Maternal and postnatal neonatal peripheral blood cytogenetic, PCR, and fluorescence in situ hybridization studies were normal, but the placenta was mosaic for 22q11.2 deletion in two of three biopsy sites. This case illustrates both the complexities of pre- and post-test counseling for microdeletion screening and the potential for a discordant positive microdeletion result because of confined placental mosaicism. © 2017 John Wiley & Sons, Ltd.

Parkinson's disease associated with 22q11.2 deletion: Clinical characteristics and response to treatment.

BACKGROUND: While it is known that 22q11.2 microdeletions (22q11.2-del) increase the risk of Parkinson's disease (PD), the characteristics of PD associated with 22q11.2-del have not been specifically explored. OBJECTIVE: This report aimed to assess the clinical characteristics and treatment responses of PD patients with 22q11.2-del, and to describe any features that might lead neurologists to investigate the comorbidity. METHODS: Nine PD patients (eight men, one woman) with 22q11.2-del were followed at seven centers of the French PD Expert Network (Ns-Park). RESULTS: PD diagnosis was made before 22q11.2-del diagnosis in seven cases; their main characteristics were early onset (32-48 years) and good initial levodopa sensitivity, but with a course characterized by severe and early-onset levodopa-induced motor complications and psychiatric manifestations. Three patients received deep brain stimulation (DBS) that was effective. CONCLUSION: Searching for 22q11.2-del in PD patients presenting with suggestive features is relevant as the clinical presentation is similar to idiopathic PD, but with other associated characteristics, including a severe evolution. Results with DBS are similar to those reported for idiopathic PD.

Malformations of the middle and inner ear on CT imaging in 22q11 deletion syndrome.

The 22q11 deletion syndrome (22q11DS), the most frequent microdeletion syndrome in humans, presents with a large variety of abnormalities. A common abnormality is hearing impairment. The exact pathophysiological explanation of the observed hearing loss remains largely unknown. The aim of this study was to analyze the middle and inner ear malformations as seen on computer tomographic imaging in patients with 22q11DS. We retrospectively reviewed the charts of 11 22q11DS patients who had undergone a CT of the temporal bone in the past. Of the 22 examined ears, two showed an abnormal malleus and incus, 10 presented with a dense stapes superstructure, and three ears had an abnormal orientation of the stapes. With regard to the inner ear, 12 ears showed an incomplete partition type II with a normal vestibular aqueduct. In four ears the vestibule and lateral semicircular canal were composed of a single cavity, in 14 ears the vestibule was too wide, and three ears had a broadened lateral semicircular canal. These findings suggest that malformations of the stapes, cochlea, vestibule, and lateral semicircular canal are frequent in 22q11DS. To our knowledge, the current study involves the largest case series describing middle and inner ear malformations in 22q11DS. © 2016 Wiley Periodicals, Inc.

The Effect of Loudness Variation on Velopharyngeal Function in Children with 22q11.2 Deletion Syndrome: A Pilot Study.

OBJECTIVE: Children with 22q11.2 deletion syndrome (22qDS) often require surgical intervention to treat velopharyngeal dysfunction (VPD). Although some studies have documented improved velopharyngeal (VP) closure under increased speaking effort, currently no studies have examined the effect of similar behavioral speech modifications on VP closure in children with 22qDS. The purpose of this pilot study was to explore the effect of loudness on VP closure during speech in children with 22qDS and persisting VPD. PATIENTS AND METHODS: Four children with 22qDS, posterior pharyngeal flap, and persisting mild VPD underwent pressure-flow testing while repeating words at habitual and increased loudness levels. Using a single-subject A-B design, descriptive statistics and graphical measures were used to examine differences in VP orifice area (VPA) and timing of closure in the habitual versus loud condition. RESULTS: Results were mixed. Median VPA decreased during some stimuli for 3 participants, but increased for 1 subject when speaking louder. Median duration of nasal airflow decreased for 3 participants in the loud condition. CONCLUSION: This study presents preliminary aerodynamic data regarding the plasticity of VP physiology in the 22qDS group. Further research is needed to determine how loudness impacts VP function in children with 22qDS.

[Catch-22? Wide variety of phenotypes associated with the chromosome 22q11 deletion syndrome in two patients]. / A 22-es csapdája? A 22q11 kromoszóma deletiós szindróma változatos klinikai megjelenése két eset kapcsán.

The chromosome 22q11 deletion syndrome may present with a variety of phenotypes. Its symptoms generally include a characteristic facial dysmorphisms and multiplex developmental disorders. Fluorescence in situ hybridization is the current method of choice for the diagnosis if typical multiple defects and/or symptoms are present. The authors present the history of two patients who were followed-up for minor anomalies and various developmental disorders for several years in the genetic counseling office of the authors, but definitive diagnosis was not established. However, when DNA samples of the two patients were recently tested with array comparative genome hybridization, a diagnostic method which has already been used in their institute for several years, the results indicated deletion of the 11.2 region on the long arm of chromosome 22 in both patients. The authors draw attention to the incidence and wide phenotypic spectrum of the chromosome 22q11 deletion syndrome, and show that its identification can be aided with the novel molecular cytogenetic method available in their laboratory.

Retrospective analysis of TREC based newborn screening results and clinical phenotypes in infants with the 22q11 deletion syndrome.

PURPOSE: Population-based newborn screening using T-cell receptor excision circles (TREC) identifies infants with severe T-lymphopenia, seen in severe combined immunodeficiencies (SCID), but also infants with the 22q11 deletion syndrome (22q11DS). Methods for analysis of kappa-deleting recombination excision circles (KREC) help identifying infants with B-lymphopenia. We aimed to evaluate the occurrence of abnormal TREC or KREC newborn screening results in 22q11DS patients and assessed the clinical relevance of abnormal screening reports. METHODS: Simultaneous TREC and KREC analysis was performed on stored original Guthrie cards. Patients with abnormal screening reports were compared to patients with normal reports, regarding lymphocyte counts and clinical severity, obtained by retrospective analysis of medical charts. RESULTS: Of 48 included patients, nine (19 %) had abnormal TREC copy numbers. All 22q11DS patients with abnormal TRECs had CD3+ T-lymphopenia at the time of diagnosis, but only one patient had the complete DiGeorge syndrome. Identified 22q11DS patients with abnormal TREC copy numbers showed significantly lower CD8+ T-lymphocytes at time-of-diagnosis and were significantly more prone to viral infections, compared to 22q11DS patients with normal TREC copy numbers. All 22q11DS patients showed KREC copies within the normal range. CONCLUSIONS: In this retrospective study a high proportion of 22q11DS patients were identified by TREC-based newborn screening. Although only one of them had the complete DiGeorge syndrome with no T-lymphocytes, all of them had T-lymphopenia and most of them had recurrent viral infections, as well as other medical problems, warranting early recognition of the syndrome.

Fetal phenotype associated with the 22q11 deletion.

The 22q11 deletion syndrome is one of the most common human microdeletion syndromes, with a wide spectrum of abnormalities. The fetal phenotype associated with the 22q11 deletion is poorly described in the literature. A national retrospective study was performed from 74 feto-pathological examinations. The objectives were to evaluate the circumstances of the 22q11 deletion diagnosis and to describe fetal anomalies. Post mortem examinations were performed after 66 terminations of pregnancy and eight fetal deaths. The series included nine fetuses from the first trimester, 55 from the second trimester, and ten from the third trimester. A 22q11 FISH analysis was recommended for 57 fetuses after multidisciplinary prenatal diagnostic counseling and for 17 fetuses by a fetal pathologist. Conotruncal heart defects were the most common anomalies (65 fetuses), followed by thymus defects (62 fetuses), and malformations of the urinary tract (25 fetuses). This study identified several unusual and severe features rarely described in the literature. Neurological abnormalities were described in ten fetuses, with seven neural tube defects and five arhinencephalies. This series also included lethal malformations: two hypoplastic left heart syndromes, two bilateral renal agenesis, and one tracheal agenesis. Genetic analysis for a 22q11 deletion is usually indicated when a congenital conotruncal heart and/or thymus defect is detected, but might also be useful in case of other lethal or severe malformations that initially led to the termination of pregnancy.

Definition of 5q11.2 microdeletion syndrome reveals overlap with CHARGE syndrome and 22q11 deletion syndrome phenotypes.

Microdeletions of the 5q11.2 region are rare; in literature only two patients with a deletion in this region have been reported so far. In this study, we describe four additional patients and further define this new 5q11.2 microdeletion syndrome. A comparison of the features observed in all six patients with overlapping 5q11.2 deletions showed a phenotypic spectrum that overlaps with CHARGE syndrome and 22q11.2 deletion syndrome including choanal atresia, developmental delay, heart defects, external ear abnormalities, and short stature. No colobomas or abnormalities of semicircular canals and olfactory nerves were reported. Two male patients had genital abnormalities. We estimated a 2.0 Mb (53.0-55.0 Mb) Shortest Region of Overlap (SRO) for the main clinical characteristics of the syndrome. This region contains nine genes and two non-coding microRNAs. In this region DHX29 serves as the candidate gene as it encodes an ATP-dependent RNA-helicase that is involved in the initiation of RNA translation. Screening a small cohort of 14 patients who presented the main features, however, did not reveal any pathogenic abnormalities of DHX29.

Negotiating identity at the intersection of paediatric and genetic medicine: the parent as facilitator, narrator and patient.

This article identifies a significant transformation in the role and identity of parents accompanying their child to clinic. This shift is a product of the intersection between paediatric and genetic medicine, where parents play a critical role in providing information about their child, family and ultimately, about themselves. To provide a context for this matrix, two broad areas of sociological inquiry are highlighted. The first is explanations of the role a parent plays in paediatric medicine and the second is the diagnostic process in paediatric genetics and the implications for parent and child identities. Drawing from an ethnographic study of clinical consultations, attention is paid to the changing role of parenthood and the extended role of patienthood in paediatric genetic medicine.

Co-occurrence of 22q11 deletion syndrome and HDR syndrome.

22q11 deletion syndrome is one of the most common chromosomal deletion syndromes and is usually caused by a 1.5-3.0 Mb deletion at chromosome 22q11.2. It is characterized by hypocalcemia resulting from hypoplasia of the parathyroid glands, hypoplasia of the thymus, and defects of the cardiac outflow tract. We encountered a Japanese boy presenting with an unusually severe phenotype of 22q11 deletion syndrome, including progressive renal failure and severe intellectual disabilities. Diagnostic testing using fluorescent in situ hybridization revealed deletion of the 22q11 region, but this did not explain the additional complications. Copy number analysis was therefore performed using whole genome single nucleotide polymorphism (SNP) assay, which identified an additional de novo deletion at 10p14. This region is the locus for hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome caused by haploinsufficiency of GATA3. Together, these two syndromes sufficiently explain the patient's phenotype. This is the first known case report of the co-occurrence of 22q11 deletion syndrome and HDR syndrome. As the two syndromes overlap clinically, this study indicates the importance of carrying out careful clinical and genetic assessment of patients with atypical clinical phenotypes or unique complications. Unbiased genetic analysis using whole genome copy number SNP arrays is especially useful for detecting such rare double mutations.

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.

Growth in Chilean infants with chromosome 22q11 microdeletion syndrome.

Chromosome 22q11 microdeletion syndrome has a wide range of clinical manifestations including congenital heart malformations, palatal defects, endocrine abnormalities, immunologic deficits, learning difficulties, and an increased predisposition to psychiatric disease. Short stature and poor weight gain in infancy are common findings and are usually seen in the absence of hormone deficiencies. An increased frequency of obesity has been observed in adolescents and adults. We generated gender-specific growth curves from 0 to 24 months of age, based on 479 length and 475 weight measurements from 138 Chilean patients with 22q11 deletion. Final adult height and weight on 25 individuals were analyzed. The 10th, 50th, and 90th centile-smoothed curves for infants were built using the LMS method and compared with World Health Organization Child Growth Standards. The 50th centile for length in the deleted patients was slightly lower than the 10th centile of WHO standards in boys and girls. The same was observed for weight, although a trend toward a gradual increase near 2 years of age was observed, particularly in boys. Average adult height was 152 cm (ranging from 143 to 162 cm) in females, corresponding to the 10th centiles of WHO standards, and 166 cm for males (160-172 cm), at the 20th centile of WHO standards. A third of the adult females and none of the males had body mass index (BMI) greater than 25. The curves should be useful to monitor growth in infants with 22q11 microdeletion syndrome.

Interrupted left aortic arch and isolated right subclavian artery from the right pulmonary artery.

We report a 10-day-old newborn, weighing 2.9 kg with an interrupted left aortic arch type B, a large subarterial ventricular septal defect and a right ductus connecting the right pulmonary artery to an isolated right subclavian artery. The patient underwent successful total surgical repair and the isolated right subclavian artery was ligated. He was discharged from hospital without complication and maintains excellent perfusion to the right arm via collaterals.

Head and neck manifestations of 22q11.2 deletion syndromes.

The allelic loss of 22q11.2 results in various developmental failures of pharyngeal pouch derivatives ("22q11.2 deletion syndromes", 22q.11DS), consequently affecting the anatomy and physiology of head and neck (H&N) organs. The objective of this paper was to describe those manifestations. Two 22q11.2DS patients with H&N manifestations were studied along with a comprehensive review of the English literature, from 1975 to 2010 regarding the associated H&N malformations among 22q11.2DS. A 24-year-old mentally disabled 22q11.2DS male presented with right hemithyroid enlargement, causing significant compressive signs. Sonography revealed a homogeneous 8 × 3 cm lesion, replacing almost the entire thyroid lobe. Fine needle aspiration revealed colloid material and abundant eosinophils. The hemithyroidectomy specimen confirmed follicular adenoma. A 19-year-old mentally disabled 22q11.2DS female underwent CT-angiography due to an upper GI bleeding. The study revealed a vascular malformation in the infratemporal fossa. Reviewing the reported data regarding 22q11.2DS-associated H&N malformations revealed abnormalities and malfunctions of the thyroid gland, parathyroid glands, thymus agenesis, cleft palate, carotid artery aberrations, malformations of the larynx and trachea and esophageal dysmotility. 22q11.DS patients may present with H&N anatomical abnormalities, along with hormonal dysfunctions, which require special awareness once treatment is offered, especially when concerning anesthetic and surgical aspects. In addition, hSNF5/INI1, a tumor suppressor gene, detected at location 22q11.2 was described to be "knocked out" in some patients. This may be associated with H&N tumors reported in these patients.

Microduplication 22q11.2: a description of the clinical, developmental and behavioral characteristics during childhood.

Microduplication 22q11.2 is a recently discovered genomic disorder. So far, targeted research on the cognitive and behavioral characteristics of individuals with this microduplication is limited. Therefore, 11 Flemish children (3-13 years old) with a microduplication 22q 1.2 were investigated in order to describe their clinical, developmental and behavioral characteristics. We measured their general intelligence, visual-motor capacities, attention, behavioral problems and characteristics of autism. In addition, there was an interview with the parents on developmental history and we reviewed available information from other specialists. The results show that the cognitive and behavioral phenotype of the children with microduplication 22q.11.2 is very wide and heterogeneous. Some of the children have a cognitively nearly normal development whereas others are more severely affected. All children had some degree of developmental delay and some of them have an intellectual disability. The most common clinical features include congenital malformations such as heart defects and cleft lip, feeding problems, hearing impairment and facial dysmorphism. The most common non-medical problems are learning difficulties, motor impairment, attention deficits, social problems and behavioral problems. There is no correlation between the size of the duplication and the phenotype.