22q11 Microdeletion Syndrome Research Articles

Prenatal diagnosis of 22q11 microdeletion syndrome

To establish a method for the prenatal diagnosis of 22q11 microdeletion syndrome. BACs-on-Beads (BoBs) and fluorescence in situ hybridization (FISH) were performed on a fetus for whom amniotic chromosomal culturing has failed and a pair of twin fetuses suspected for 22q11 deletion syndrome. 22q11 microdeletion was detected in all 3 fetuses by prenatal BoBs as well as FISH, with only one red signal detected at the DiGeorge/VCFS N25 site and two green signals on the 22q13.3 ARSA site. The combination of prenatal BoBs and FISH can provide a method for the prenatal diagnosis of 22q11 microdeletion.

Application of chromosome microarray analysis for fetuses with multicystic dysplastic kidney

To explore the genetic etiology of fetuses with multicystic dysplastic kidney (MCDK) by chromosome microarray analysis (CMA). Seventy-two fetuses with MCDK were analyzed with conventional cytogenetic technique, among which 30 fetuses with a normal karyotype were subjected to CMA analysis with Affymetrix CytoScan HD arrays by following the manufacturer's protocol. The data was analyzed with ChAS software. Conventional cytogenetic technique has revealed three fetuses (4.2%) with identifiable chromosomal aberrations. CMA analysis has detected pathogenic CNVs in 5 fetuses (16.7%), which included two well-known microdeletion or microduplication syndromes, i.e., 17q12 microdeletion syndrome and Williams-Beuren syndrome (WBS) and three submicroscopic imbalances at 4q35.2, 22q13.33, and 1p33. PEX26, FKBP6, TUBGCP6, ALG12, and CYP4A11 are likely the causative genes. CMA can identify the submicroscopic imbalances unidentifiable by conventional cytogenetic technique, and therefore has a significant role in prenatal diagnosis and genetic counseling. The detection rate of pathogenic CNVs in fetuses with MCDK was 16.7% by CMA. 17q12 microdeletion syndrome and WBS are associated with MCDK. Mutations of PEX26, FKBP6, TUBGCP6, ALG12, and CYP4A11 genes may be the causes for MCDK.

P01.08: The 22q11 microdeletion syndrome: a review of prenatal ultrasonographic findings and the relation with diagnostic prenatal testing

P01.08: The 22q11 microdeletion syndrome: a review of prenatal ultrasonographic findings and the relation with diagnostic prenatal testing

P25.05: Systematic review of the prenatal ultrasound findings among women with bright echogenic kidneys secondary to 17q12 microdeletion syndrome

P25.05: Systematic review of the prenatal ultrasound findings among women with bright echogenic kidneys secondary to 17q12 microdeletion syndrome

Pattern of Congenital Heart Defects in 22q11 Microdeletion Syndrome in India – A Tertiary Care Cardiac Hospital Based Study

<p><em>Background</em>: To investigate pattern of Congenital Heart Defects in 22q11 microdeletion syndrome.</p><p><em>Methods</em>: A retrospective study from year 2006 to 2015 of children with 22q11 microdeletion and pattern of Congenital Heart Defects.</p><p><em>Results</em>: Ninety-Six children with Fluorescent in-situ Hybridisation positive for 22q11.2 microdeletion and Congenital Heart Defects were identified. Out of these 96, the most common Congenital Heart Defect variants were Tetralogy of Fallot (39.58%), Pulmonary Atresia with Ventricular Septal Defect (29.16%), and isolated Ventricular Septal Defect (10.4%). Conotruncal defects constituted majority (82%) followed by Ventricular Septal Defects. Two rare associations were: one child with mitral valve prolapse & another with left pulmonary vein stenosis.</p><p><em>Conclusion</em>: 22q11.2 microdeletion syndrome is commonly associated with Congenital Heart Defects. Among children with Congenital Heart Defects and 22q11.2 microdeletion, conotruncal malformations were the most common defects followed by Ventricular Septal Defect.</p>

An inferential study of the phenotype for the chromosome 15q24 microdeletion syndrome: a bootstrap analysis.

In January 2012, a review of the cases of chromosome 15q24 microdeletion syndrome was published. However, this study did not include inferential statistics. The aims of the present study were to update the literature search and calculate confidence intervals for the prevalence of each phenotype using bootstrap methodology. Published case reports of patients with the syndrome that included detailed information about breakpoints and phenotype were sought and 36 were included. Deletions in megabase (Mb) pairs were determined to calculate the size of the interstitial deletion of the phenotypes studied in 2012. To determine confidence intervals for the prevalence of the phenotype and the interstitial loss, we used bootstrap methodology. Using the bootstrap percentiles method, we found wide variability in the prevalence of the different phenotypes (3–100%). The mean interstitial deletion size was 2.72 Mb (95% CI [2.35–3.10 Mb]). In comparison with our work, which expanded the literature search by 45 months, there were differences in the prevalence of 17% of the phenotypes, indicating that more studies are needed to analyze this rare disease.

Duodenal Obstruction Associated With 3q29 Microdeletion Syndrome in a 10-Year-Old Child

Duodenal Obstruction Associated With 3q29 Microdeletion Syndrome in a 10-Year-Old Child

AB024. Chromosome microarray analysis (CMA) for the diagnosis of children with developmental delay and multiple congenital anomalies in Singapore.

Chromosome microarray analysis (CMA) is a sensitive method to identify submicroscopic changes too small to be detected by conventional karyotyping. Due to its high-sensitivity in identifying regions with structural variation and hence the genes involved, it is recommended to be the first-tier genetic test for children with intellectual disabilities, development delay or multiple congenital anomalies, and is routinely available in USA and many countries in Europe. Our lab has started offering this as a clinical test based on the research experience on screening >400 children with developmental delay and multiple congenital anomalies since February 2014. To date, 271 patients have been screened using the Agilent 4×180K CGH + SNP array. Copy number variants (CNVs) ranging in size from 10 kb to 154 Mb were found in 109 patients (40%). Pathogenic and likely pathogenic CNVs were found in 55 (20%). These included 45 with deletions, 8 with duplications and 2 patients with both deletion and duplication. Recurrent microdeletion and microduplication syndromes including the Angelman/Prader-Willi syndrome [5], 1p36 microdeletion [3], Williams syndrome [2], 22q11.2 distal deletion syndrome [2], 16p13.3 microdeletion syndrome [2], Cat Eye syndrome, Cri du Chat syndrome, Miller Decker syndrome, 3q29 microdeletion, 15q24 microdeletion, and 1q43q44 syndrome were among the variants detected in our patients. CNVs of uncertain clinical significance were detected in 54 (20%) individuals: 32 were duplications, 18 were deletions and one with both deletion and duplication. However, due to the high cost of the test, parental testing was not performed and hence, significance of these variants could not be established conclusively. In conclusion, CMA is a powerful tool in identifying pathogenic chromosomal copy number alternations. However, due to the high cost of the test, parental testing for the cases where variants of uncertain significant are found is often not possible. CMA is useful in identifying pathogenic structural rearrangement. More data are necessary to be collected to enhance interpretation of the results.

Application of chromosome microarray analysis for fetuses with increased nuchal translucency and a normal karyotype

To explore the genetic etiology for fetuses with increased nuchal translucency (NT) but a normal karyotype at whole genome level by chromosome microarray analysis (CMA). Seventy-eight fetuses with increased NT (≥ 3.0 mm) but a normal karyotype were collected between 11(+0) and 13(+6) gestational weeks. Genomic DNA was extracted, and microarray testing was performed using Affymetrix CytoScan(TM) HD arrays. The data was analyzed by CHAS software. All detected copy number variations (CNVs) were confirmed with real-time quantitative polymerase chain reaction. The CMA assay has detected pathogenic CNVs in 6 fetuses (7.69%), which have ranged from 0.41 Mb to 15.87 Mb. Well-known microdeletion or microduplication syndromes including Wolf-Hirschhorn syndrome, 22q11 microdeletion syndrome and ATR-16 syndrome were identified in three cases. The detection rates in fetuses with or without structural abnormalities were 18.18% and 5.97%, respectively (P=0.198 with Fisher's Exact Test). The average NT in fetuses with pathogenic CNVs and non-pathogenic CNVs has measured 4.48 mm and 4.22 mm (P=0.735 by Mann-Whitney Test). For fetuses with increased NT, CMA can identify chromosomal microdeletion/microduplication unrecognizable by conventional karyotyping analysis. It may therefore play an important role in prenatal diagnosis and genetic counseling by improving the diagnostic rate.

A splicing mutation of the HMGA2 gene is associated with Silver-Russell syndrome phenotype.

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by intrauterine and post-natal growth retardation, dysmorphic facial features and body asymmetry. About 50% of the patients carry (epi)genetic alterations involving chromosomes 7 or 11.The high proportion of patients with unidentified molecular etiology suggests the involvement of other genes. Interestingly, SRS patients share clinical features with the 12q14 microdeletion syndrome, characterized by several deletions with a 2.6 Mb region of overlap. Among the genes present in this interval, high mobility AT-hook 2 (HMGA2) appears to be the most likely cause of the growth deficiency, due to its described growth control function. To define the role of HMGA2 in SRS, we looked for 12q14 chromosome imbalances and HMGA2 mutations in a cohort of 45 patients with growth retardation and SRS-like phenotype but no 11p15 (epi)mutations or maternal uniparental disomy of chromosome 7 (matUPD7). We identified a novel 7 bp intronic deletion in HMGA2 present in heterozygosity in the proband and her mother both displaying the typical features of SRS. We demonstrated that the deletion affected normal splicing, indicating that it is a likely cause of HMGA2 deficiency. This study provides the first evidence that a loss-of-function mutation of HMGA2 can be associated with a familial form of SRS. We suggest that HMGA2 mutations leading to haploinsufficiency should be investigated in the SRS patients negative for the typical 11p15 (epi)mutations and matUPD7.

Inherited 15q24 microdeletion syndrome in twins and their father with phenotypic variability

BackgroundDeletions including chromosome 15q24 have been delineated in recent years as a separate syndrome with phenotypic variability. Here we report a familial 15q24 deletion and further contribute to the phenotypic description of this syndrome. MethodsMolecular karyotyping and description of the phenotype of three patients in the same family with a 15q24 deletion. ResultsParental transmission of the 15q24 deletion syndrome is described in the same family. The affected, the father and his twin offspring, all exhibit the typical facial features, signs and symptoms consistent with the syndromic phenotype. A distinct phenotypic variability is nevertheless noted although they all share the same deletion. ConclusionsThese three patients are to our knowledge the first described cases of 15q24 syndrome in the same family. Urogenital malformations have previously been described as a part of this syndrome. Our adult male patient exhibits no such malformations but has a documented reduced fertility. This fact points to other factors such as haploinsufficiency of one and/or further genes on 15q24 as being responsible for the infertility. Array analysis could be considered as a first hand analysis in the investigation of cases of infertility and intellectual deficiency in adults in analogy to the existing consensus regarding cases of intellectual deficiency in children.

Case fatality rate and associated factors in patients with 22q11 microdeletion syndrome: a retrospective cohort study

ObjectiveChromosome 22q11.2 deletion is the most commonly occurring known microdeletion syndrome. Deaths related to the syndrome have been reported, but the magnitude of death has not been quantified. This study...

Towards a new point of view on the phenotype of patients with a 17q12 microdeletion syndrome

Objective17q12 microdeletion syndrome involves 15 genes, including HNF1B, and is considered to confer a high risk of neuropsychiatric disorders. Patients with HNF1B gene deletion diagnosed secondary to renal disorders are...

Maturation of cortical circuits requires Semaphorin 7A.

Abnormal cortical circuits underlie some cognitive and psychiatric disorders, yet the molecular signals that generate normal cortical networks remain poorly understood. Semaphorin 7A (Sema7A) is an atypical member of the semaphorin family that is GPI-linked, expressed principally postnatally, and enriched in sensory cortex. Significantly, SEMA7A is deleted in individuals with 15q24 microdeletion syndrome, characterized by developmental delay, autism, and sensory perceptual deficits. We studied the role that Sema7A plays in establishing functional cortical circuitry in mouse somatosensory barrel cortex. We found that Sema7A is expressed in spiny stellate cells and GABAergic interneurons and that its absence disrupts barrel cytoarchitecture, reduces asymmetrical orientation of spiny stellate cell dendrites, and functionally impairs thalamocortically evoked synaptic responses, with reduced feed-forward GABAergic inhibition. These data identify Sema7A as a regulator of thalamocortical and local circuit development in layer 4 and provide a molecular handle that can be used to explore the coordinated generation of excitatory and inhibitory cortical circuits.

Genomic Analyses of Patients With Unexplained Early-Onset Scoliosis

Study DesignTo test for rare genetic mutations, a cohort of patients with unexplained early-onset scoliosis (EOS) was screened using high-density microarray genotyping. A cohort of patients with adolescent idiopathic scoliosis (AIS) was similarly screened and the results were compared. Summary of Background DataPatients with scoliosis in infancy or early childhood (EOS) are at high risk for progressive deformity and associated problems including respiratory compromise. Early-onset scoliosis is frequently associated with genetic disorders but many patients present with nonspecific clinical features and without an associated diagnosis. The authors hypothesized that EOS in these patients may be caused by rare genetic mutations detectable by next-generation genomic methods. MethodsThe researchers identified 24 patients with unexplained EOS from pediatric orthopedic clinics. They genotyped them, along with 39 connecting family members, using the Illumina OmniExpress-12, version 1.0 beadchip. Resulting genotypes were analyzed for chromosomal changes, specifically copy number variation and absence of heterozygosity. They screened 482 adolescent idiopathic scoliosis (AIS) patients and 744 healthy controls, who were similarly genotyped with the same beadchip, for chromosomal changes identified in the EOS cohort. ResultsCopy number variation and absence of heterozygosity analyses revealed a genetic diagnosis of chromosome 15q24 microdeletion syndrome in 1 patient and maternal uniparental disomy of chromosome 14 in a second one. Prior genetic testing and clinical evaluations had been negative in both cases. A large novel chromosome 10 deletion was likely causal in a third EOS patient. These mutations identified in the EOS patients were absent in AIS patients and controls, and thus were not associated with AIS or found in asymptomatic individuals. ConclusionsThese data underscore the usefulness of updated genetic evaluations including high-density microarray-based genotyping and other next-generation methods in patients with unexplained EOS, even when prior genetic studies were negative. These data also suggest the intriguing possibility that other mutations detectable by whole genome sequencing, as well as epigenetic effects, await discovery in the EOS population.

Endocrinological anomalies in a patient with 12q14 microdeletion syndrome. Completing phenotype of this exceptional short stature condition

12q14 microdeletion syndrome consists of the association of short stature, mental retardation, and osteopoikilosis. Since its first description in 2007, there have been <20 cases reported and each case presented variable phenotypes. We present a girl with 12q14 microdeletion that showed mental retardation and short stature but without osteopoikilosis. She also exhibited precocious puberty and growth hormone deficiency and required treatment for improving final height. This report adds further to the knowledge of the endocrinological anomalies in 12q14 microdeletion syndrome. It is important to perform growth hormone level measurements and pubertal signs to follow-up with these patients and avoid the consequential adult height worsening.

3q29 microdeletion syndrome: Cognitive and behavioral phenotype in four patients

The 3q29 microdeletion syndrome is a rare, recurrent genomic disorder, associated with a variable phenotype, despite the same deletion size, consisting in neurodevelopmental features, such as intellectual disability (ID), schizophrenia, autism, bipolar disorder, depression and mild facial morphological anomalies/congenital malformations. A thorough neuropsychiatric evaluation has never been reported in patients with such syndrome. We analyzed the clinical phenotype of four individuals with 3q29 microdeletion syndrome, with special emphasis on the cognitive and behavioral assessment, in order to delineate the neuropsychiatric phenotype related to this condition. We assessed these patients with standardized scales or checklists measuring the cognitive (WISC III or LIPS-R), behavioral (CBCL) and adaptive (VABS) performances. An accurate evaluation in our sample highlights different degrees of ID, variable behavioral disorders, and a preservation of communicative skills among remaining adaptive areas, as the neuropsychiatric hallmark of 3q29 microdeletion syndrome.

Anxiety and affective disorder comorbidity related to serotonin and other neurotransmitter systems: obsessive–compulsive disorder as an example of overlapping clinical and genetic heterogeneity

Individuals with obsessive-compulsive disorder (OCD) have also been shown to have comorbid lifetime diagnoses of major depressive disorder (MDD; rates greater than 70%), bipolar disorder (rates greater than 10%) and other anxiety disorders (e.g. panic disorder, post-traumatic stress disorder (PTSD)). In addition, overlap exists in some common genetic variants (e.g. the serotonin transporter gene (SLC6A4), the brain-derived neurotrophic factor (BDNF) gene), and rare variants in genes/chromosomal abnormalities (e.g. the 22q11 microdeletion syndrome) found across the affective/anxiety disorder spectrums. OCD has been proposed as a possible independent entity for DSM-5, but by others thought best retained as an anxiety disorder subtype (its current designation in DSM-IV), and yet by others considered best in the affective disorder spectrum. This review focuses on OCD, a well-studied but still puzzling heterogeneous disorder, regarding alterations in serotonergic, dopaminergic and glutamatergic neurotransmission in addition to other systems involved, and how related genes may be involved in the comorbidity of anxiety and affective disorders. OCD resembles disorders such as depression, in which gene × gene interactions, gene × environment interactions and stress elements coalesce to yield OC symptoms and, in some individuals, full-blown OCD with multiple comorbid disorders.

The 22q11 microdeletion syndrome in children

DiGeorge syndrome is a primary immunodeficiency with microdeletion 22q11. Prenatal diagnosis is possible. Typical disorders are heart defects of heart and large vessels, hypoplasia of the parathyroid glands, dysmorphia, no thymus and immune deficiency. The primary problem is the heart defect requiring cardiac surgical intervention. Due to the severi ty of the operation, immunodeficiency often goes into the background. Infections are associated with cardiovascular abnormalities. The immune deficit is omitted without proper treatment including isola tion of the patient, substitution of i.v. immunoglobulin, chemo-prophylaxis. Blood products must be irra diated. What should be applied is oncology alertness and limitation of X-ray should also be noted. A com prehensive care reduces infections and improves the quality of life.

12q14 microdeletion associated with HMGA2 gene disruption and growth restriction

The 12q14 microdeletion syndrome is a rare condition that has previously been characterized by pre- and postnatal growth restriction, proportionate short stature, failure to thrive, developmental delay, and osteopoikilosis. Previously reported microdeletions within this region have ranged in size from 1.83 to 10.12 Mb with a proposed 2.61 Mb smallest region of overlap containing the LEMD3, HMGA2, and GRIP1 genes. Here, we report on the identification of a 12q14 microdeletion in a female child presenting with proportionate short stature, failure to thrive, and speech delay. The genomic loss (minimum size 4.17 Mb, maximum size 4.21 Mb) contained 25 RefSeq genes including IRAK3, GRIP1, and the 3' portion of the HMGA2 gene. This is the first partial deletion of HMGA2 associated with the 12q14 microdeletion syndrome. This case further clarifies the association of LEMD3 deletions with the 12q14 microdeletion syndrome and provides additional support for the role of the HMGA2 gene in human growth.