Chromosomal Microarray Research Articles

Clinical, Immunologic, and Genetic Characteristics of T-lymphoblastic Leukemia with STIL-TAL1 Fusion.

T-lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with a less favorable prognosis. The genetic background of T-ALL is widely heterogeneous, with the co-occurrence of multiple genetic abnormalities. The STIL-TAL1 rearrangement results from a submicroscopic deletion on chromosome 1p33 and is present in 15 - 25% of T-ALL cases. Submicroscopic deletions are not detected by conventional cytogenetic ana-lyses but can be identified through array comparative genomic hybridization and/or high-throughput RNA sequencing. Patients with the STIL-TAL1 fusion exhibit distinct characteristics, such as a young age, high white blood cell count, typical immunophenotype, and specific genetic abnormalities. However, the clinical, laboratory, and prognostic significance of this rearrangement remains unclear. This study was performed to identify STIL-TAL1 rearrangement resulting from submicroscopic 1p33 deletion in T-ALL and to investigate the clinical, immunologic, and genetic characteristics of T-ALL patients with STIL-TAL1 fusion. A total of 15 T-ALL patients were enrolled over a 6-year period (2018 - 2023). We evaluated clinical features and laboratory findings, including immunophenotyping, multiplex reverse transcriptase-polymerase chain reaction (RT-PCR), karyotype analysis, next-generation sequencing (NGS), and chromosomal microarray analysis (CMA), on bone marrow or peripheral blood specimens at the diagnostic stage. Multiplex RT-PCR was performed on 15 cases of T-ALL, and STIL-TAL1 fusion was detected in 3 cases (20.0%, 3/15). STIL-TAL1-positive patients were all male, under 40 years of age, and presented with lymph node enlargement, hepatosplenomegaly, and mediastinal mass. They showed relatively higher leukocyte counts and hemoglobin levels, but lower platelet counts compared to STIL-TAL1 negative cases. Immunophenotyping analysis revealed higher sCD3 and lower CD34 expression with no aberrant myeloid lineage expression. CMA demonstrated a 63-kb heterozygous deletion at 1p33, along with additional copy number abnormalities such as TCR rearrangements and a biallelic CDKN2A deletion. The T-ALL with STIL-TAL1 fusion exhibits unique clinical, immunologic, and genetic characteristics. Further multi-center studies, incorporating cytogenetic and molecular analyses, are needed to elucidate the detailed pathophysiology, characteristics, and clinical significance of this gene rearrangement.

P787: Unbalanced three-way translocation identified in a patient with developmental delay using chromosomal microarray analysis and karyotyping

P787: Unbalanced three-way translocation identified in a patient with developmental delay using chromosomal microarray analysis and karyotyping

P743: What are you missing? A review of the utility of characterization studies as part of chromosomal microarray analysis

P743: What are you missing? A review of the utility of characterization studies as part of chromosomal microarray analysis

P809: Prenatal chromosomal microarray classification and reporting among screen positive cases in California

P809: Prenatal chromosomal microarray classification and reporting among screen positive cases in California

P827: Expanded chromosomal microarray comprising screening for spinal muscular atrophy and monogenic diseases in prenatal diagnosis

P827: Expanded chromosomal microarray comprising screening for spinal muscular atrophy and monogenic diseases in prenatal diagnosis

Chromosomal microarray analysis in pregnancies with prenatal ultrasound abnormalities according to the involved organ systems

Purpose: Chromosomal microarray (CMA) is a high-resolution technique that can identify submicroscopic chromosomal aberrations or copy number variants (CNVs). We aimed to analyze the frequency of significant CNVs according to the involved organ systems in fetuses with ultrasound-detected abnormalities. Materials and Methods: This study was a retrospective observational study. We conducted the study between April 2019 and July 2023, including fetuses with abnormal ultrasound findings and normal karyotyping results. We analyzed the CNVs results according to organ systems. Results: A total of 346 prenatal CMA were performed during the study periods, and there were 164 (47.4%) cases with abnormal ultrasound findings. In 9 (5.5%) of the 164 cases with a normal karyotype, significant CNVs were detected. The frequency of significant CNVs was higher in cases involving multiple organ systems than in single organ systems (12.5% vs. 5.1%). The distribution of significant CNVs by single organ systems was as follows: genitourinary 16.7% (1/6), face and neck 16.7% (1/6), cardiac 7.7% (1/13), early-onset fetal growth restriction 7.7% (1/13), and increased nuchal translucency 4.6% (4/87). We confirmed that prenatal CMA is a useful diagnostic tool in cases of ultrasound abnormalities. Additionally, we demonstrated that the frequency of significant CNVs varies according to the organ systems. We expect that collecting and analyzing more cases will aid in improving for prenatal CMA when there are ultrasound abnormalities are detected.

The Value of ROH Metrics for Predicting Morbidity: Insights From a Large Cohort Analysis of Chromosomal Microarray.

This retrospective cohort study aimed to define the optimal Regions of Homozygosity (ROH) size cut-offs for prediction of morbidity, based on 13 483 Chromosomal Microarray Analyses (CMA). Receiver operating characteristic (ROC) curves were generated, and area under the curve (AUC) was used to assess the predictive capability of total ROH percentage (TRPS), ROH number and ROH segment size in distinguishing between healthy (n=6,196) and affected (n=6,839) cohorts. The metrics were examined for telomeric and interstitial segments, distinct TRPS categories, and across different ancestral origins. ROH segments were identified in 13 035 samples (96.7%), encompassing 66 710 ROH segments. Significant differences in TRPS and ROH segment size were observed between healthy and affected cohorts (p=0.012 and p < 0.001, respectively). However, no clinically significant thresholds could be established based on ROC curves for TRPS and ROH number per sample, as well as for ROH size (AUC 0.64, 0.55, and 0.62, respectively, Figure1). The same was noted for telomeric versus interstitial locations, various origins, and subcategories of TRPS. In conclusion, this study highlights the complexity of ROH interpretation and emphasizes the importance of tailored reporting strategies in clinical practice. Our findings underscore the need for context-specific reporting guidelines and further research, particularly in consanguineous populations.

DIAGNOSTIC VALUE OF CHROMOSOMAL MICROARRAY ANALYSIS IN PATIENTS WITH CONGENITAL ANOMALIES AND DYSMORPHIC FEATURES; DETAILS OF TWO NEW PATIENTS WITH 2q33 DELETIONS

Objective: Detection of copy number variations (CNVs) through molecular karyotyping is a useful method to assess the genetic anomalies with dysmorphic features and multiple congenital anomalies. This study demonstrated the diagnostic rate of chromosomal microarray analysis in patients with specific phenotype, and also contributed the literature with presenting new patients with very rare CNVs. Material and Methods: Chromosomal microarray analysis was performed in 419 patients with dysmorphic features and multiple congenital anomalies. Results: A total of 61 CNVs were detected in 50 patients (12%). Two of these patients exhibited a 2q33.1 deletion. While patient 13 presented with speech delay, seizures, behavioral abnormalities, and a 469 kbp deletion disrupting SATB2, patient 14 displayed immune deficiency, failure to thrive, hypothyroidism, diarrhea, cryptorchidism, and ectodermal features such as alopecia, nail dysplasia, and oligodontia. This patient had a 7.5 Mb deletion on 2q33.1q34, which included CTLA4 and was responsible for the immune deficiency symptoms of the patient. The CASP10, was not included in the deletion region. Conclusions: According to our study, co-deletion of CTLA4 and CASP10 did not lead to phenotypic effects like immune deficiency. Rather, only the deletion of the CTLA4 gene may result in hypogammaglobulinemia and immune deficiency. These findings suggest that chromosomal microarray analysis can be a valuable tool in diagnosing rare CNVs and guiding clinical management, particularly in patients with immune deficiency and other congenital anomalies. Identifying specific gene deletions, such as CTLA4, may inform personalized treatment approaches, including immune-modulating therapies, and provide insights for genetic counseling in affected families.

Nonrecurrent Triplication of 5q21.3q23.3: A Case Report and Review of the Literature.

Triplications involving 5q21.3q23.3 are rare, and a phenotype has not been established. Here, we present a 4-month-old male with dysmorphic facial features and congenital cardiac malformation. Chromosomal microarray identified a pathogenic triplication of 5q21.3q23.3 with chromosome analysis showing the extra 5q material inserted into 16q. Optical genome mapping (OGM) was performed to further characterize the triplication. We compared the clinical features of our proband with previous case reports of individuals with duplications or triplications in the region to identify a phenotype. Common features appear to include short stature, developmental delays, learning difficulties, and cardiac malformations. We discuss genes in the region with a reported role in cardiac development, hypothesize that the triplication may have resulted from microhomology-mediated break-induced replication, and discuss the utility and limitations of OGM in this case. To our knowledge, this is the first reported case of a de novo triplication of 5q21.3q23.3.

Role of copy number variation analysis in prenatally diagnosed Blake’s pouch cyst

BackgroundBlake’s pouch cyst (BPC) is a midline cystic anomaly of the posterior fossa. BPC has been shown to have a risk of aneuploidy prenatally. Copy number variation (CNV) and/or genetic syndromes have been reported in a few prenatal/postnatal cases with BPC. The purpose of this study is to determine the additional value of CNV analysis for prenatal diagnosis and prognosis evaluation of BPC.MethodsWe reviewed the sonographic findings and genetic results of BPC diagnosed within 6 years at our center. Patients were classified into the isolated and non-isolated groups based on the prenatal and postnatal imaging. We analyzed the chromosomal abnormalities by conventional karyotype analysis combined with chromosomal microarray analysis (CMA) or CNV sequencing (CNV-seq).ResultsWe recruited 467 low-risk fetuses as the control group to establish normal references of vermian area and brainstem-vermis (BV) angle. Prenatal/postnatal MRI or neonatal neurosonography was used as diagnostic criteria. 34 patients were diagnosed as BPC, including 21 (61.8%) patients with non-isolated and 13 (38.2%) with isolated. Twenty-two patients underwent CMA/CNV-seq, among them 14 patients were performed both CMA/CNV-seq and karyotype analysis. Seven (7/22, 31.8%) patients with BPC had chromosomal abnormalities, including 3 (3/22, 13.6%) patients with chromosomal aneuploidy - trisomy 21, 18 and 13, and 4 (4/22, 18.2%) patients had pathogenic CNVs located at 3p, 9p, Xp/Xq and 7p. Anomalies in fetal heart (35.3%), central nervous system (CNS) (26.5%) and limb (14.7%) were the three top anomalies accompanying BPC.ConclusionsCNV analysis could provide some additional information for prenatal diagnosis and prognosis counseling for patients with non-isolated BPC. And, it adds less value for patients with isolated BPC, however, isolated BPC can be a soft marker for aneuploidy.

Relationship between prenatal ultrasound signs and genetic abnormalities for fetal malformations of cortical development.

To explore the relationship between ultrasound signs of suspected fetal malformation of cortical development (MCD) and genetic MCD.The retrospective study involved fetuses with one of the following 10 neurosonography (NSG) signs: (A) abnormal development of the Sylvian fissure; (B) delayed achievement of cortical milestones; (C) premature or aberrant appearance of sulcation; (D) irregular border of the ventricular wall or irregular shape of the ventricle; (E) abnormal shape or orientation of the sulci; (F) hemispheric asymmetry; (G) non-continuous cerebral cortex; (H) intraparenchymal echogenic nodules; (I) persistent ganglionic eminence (GE) or GE cavitation; (J) abnormal cortical lamination.95 fetuses were included in the study. Chromosomal microarray (CMA) combined with exome sequencing (ES) was available in 40 fetuses, CMA was abnormal in nine and ES in 22. Sign C (7/7, 100%), sign H (2/2, 100%), sign A (18/19, 94.7%), and sign B (12/13, 92.3%) were the signs leading to the highest probability of genetic MCD. The incidence of genetic MCD for sign E, sign I, and sign D was 66.7-73.7%. Only one or none of the fetuses with sign J, sign F, or sign G underwent CMA+ES. The signs in the fetuses with FGFR3, CCND2, FLNA, or TSC2 mutations had the expected features. The other fetuses with different gene mutations showed several non-specific NSG signs.Several reliable signs for genetic MCD can be detected by NSG, and the probability varies with different signs. Most signs are not associated with a specific gene. Therefore, CMA combined with ES is preferred.

Genetics of Prader-Willi and Angelman syndromes: 2024 update.

Prader-Willi (PWS) and Angelman (AS) syndromes arise from errors in 15q11-q13 imprinting. This review describes recent advances in genomics and how these expand our understanding of these rare disorders, guiding treatment strategies to improve patient outcomes. PWS features include severe infantile hypotonia, failure to thrive, hypogonadism, developmental delay, behavioral and psychiatric features, hyperphagia, and morbid obesity, if unmanaged. AS presents severe intellectual disability, motor dysfunction, seizures, absent speech, and a characteristic happy demeanor. Standard-of-care testing involves SNRPN promoter methylation, microarray and genomic analyses for individuals presenting with these features. These tests identify syndromic-specific DNA methylation patterns and molecular genetic classes responsible for disease etiology. This review provides an update on studies of genotype-phenotype relationships and novel genomic technologies used for diagnostic purposes. We give an overview and update on the genetics and underlying mechanisms associated with symptoms and potential treatments with focus on features reported to be different between specific molecular genetic classes. The review also describes laboratory testing methods for diagnosis of these imprinting disorders with implications for clinical practice.

Prenatal diagnosis and molecular cytogenetic analysis of pure chromosome 10p15.3 microdeletion using chromosomal microarray analysis

BackgroundThe literature contains exceedingly limited reports on chromosome 10p15.3 microdeletions. In the present study, two cases of fetuses with pure terminal 10p15.3 microdeletion syndrome in a Chinese population were examined, with the objective of enhancing understanding of the genotype-phenotype correlation associated with 10p15.3 microdeletions.MethodsTwo fetuses with chromosome 10p15.3 microdeletion were identified from a cohort of 5,258 cases undergoing amniocentesis. Karyotyping and chromosomal microarray analysis (CMA) was conducted to assess chromosomal abnormalities and detect copy number variations (CNVs) within the families, respectively.ResultsIn Family 1, the fetus exhibited a 556.2-Kb deletion in the 10p15.3 region, encompassing OMIM genes such as DIP2C and ZMYND11, and presented with increased nuchal translucency on prenatal ultrasound examination. Parental CMA analysis revealed that the 10p15.3 microdeletion was inherited from the father, who displayed mild language impairment. In Family 2, a comparable 10p15.3 microdeletion was identified in a fetus presenting with asymmetric butterfly vertebrae at T10 and T12, along with mild scoliosis of the spine. Family 1 elected to terminate the pregnancy, while Family 2 chose to continue. At a follow-up conducted at one year and eight months, the child demonstrated delays in both speech and motor development.ConclusionThe present study is the first to report two cases of pure terminal chromosome 10p15.3 microdeletion syndrome in fetuses, offering valuable insights for the prenatal diagnosis of 10p15.3 microdeletion syndrome. Further, it is the first to describe mild clinical features, specifically limited to language impairment, in a patient with 10p15.3 microdeletion syndrome.

Genetic Diagnosis and Clinical Features of Fetuses With Congenital Diaphragmatic Hernia.

Congenital diaphragmatic hernia (CDH) is a rare abnormality with highly heterogeneous genetic causes. This study investigated chromosomal and monogenic abnormalities in fetal CDH patients and evaluated the efficacy of chromosomal microarray analysis (CMA) and whole-exome sequencing (WES) for genetic diagnosis. The clinical features of the patients were also evaluated. We evaluated the genetic and clinical data of 51 prenatally diagnosed fetuses with CDH. CMA was performed for every patient. If CMA did not yield diagnostic results, the samples were subjected to WES. Compared with fetuses with isolated CDH (n=42), those with non-isolated CDH (n=9) presented a higher genetic diagnostic rate (22.2% vs. 2.4%). The overall diagnostic yield was 5.9%, comprising 3.9% from chromosomal microarray analysis (CMA) and an additional 2.0% from whole exome sequencing (WES). CMA identified (1) mosaic trisomy 18 in a patient with isolated CDH; and (2) 4q terminal deletion syndrome in a patient with non-isolated CDH. WES identified a novel missense mutation, PLS3 c.1763A>G, associated with X-linked CDH in a patient with non-isolated CDH and a family history of recurrent CDH. Genetic testing should be offered for all fetuses with CDH, regardless of whether the cases are isolated or non-isolated. WES should be considered if CMA fails to provide a diagnostic result, particularly in patients with non-isolated CDH and a family history of recurrent CDH.

Breathing and Feeding Woes: A Neonate’s Journey through Vascular Conundrum

A baby boy, born via non-consanguineous marriage with a birth weight of 2.78Kg, presented at 11 days of life with respiratory distress. His antenatal course was uneventful, with a foetal echocardiogram showing a right aortic arch and a foetal chromosomal microarray ruling out any genetic issues. He was delivered by caesarean-section at 37 weeks due to non-progression of labour, with appearance, pulse, grimace, activity and respiration (APGAR) scores of 8 and 9 at 1 and 5 minutes, respectively. The immediate postnatal period was uneventful, and he was discharged on the third day.

Prenatal genetic detection in foetus with gallbladder size anomalies: cohort study and systematic review of the literature

Objectives The aim of the study was to evaluate the detection rate of genetic abnormalities in cases of foetal gallbladder (FGB) size abnormalities to determine whether these abnormalities justify prenatal diagnosis. Methods Two hundred and twenty-seven foetuses with gallbladder (GB) size anomalies who underwent prenatal diagnosis between January 2015 and June 2024 were included in the study. All these patients underwent chromosomal microarray and/or karyotyping, and 37 cases also underwent whole exome sequencing (WES). Two hundred and eight cases were followed up for postnatal outcomes. Then, we reviewed the literature of FGB anomalies cases with confirmed chromosomal results. Results The study included 227 foetuses, comprising 60 cases with isolated GB size anomalies and 167 cases with non-isolated GB size anomalies. Non-isolated GB size anomalies were associated with findings such as hyperechogenic bowel, ventriculomegaly, foetal growth restriction (FGR), cardiac anomalies, renal dysplasia and single umbilical artery. The overall diagnostic yield of genetic tests was 10.57% (24/227). Aneuploidies were identified in seven foetuses. Pathogenic/likely pathogenic copy number variations (CNVs) were found in nine foetuses, and α0-thalassemia in five foetuses. Additionally, three pathogenic single-nucleotide variants (SNVs) were detected through WES. Foetuses with non-isolated GB size anomalies showed a higher rate of detecting genetic abnormalities compared to those with isolated GB size anomalies, with a significant difference in statistical analysis (13.2% vs. 3.3%, p = .033, Chi-square test). A total of eight studies, involving 407 cases met the criteria for inclusion in the systematic review. Overall, 28 foetuses were identified to have chromosomal abnormalities (6.9%, 28/407). Conclusions This study indicates that parents of foetuses with GB size anomalies should be informed about the potential for aneuploidy, pathogenic CNVs and SNVs, and genetic testing should be recommended in cases of non-isolated foetal GB size anomalies.

Findings in Chromosomal Microarray Analysis during Prenatal Diagnosis in High-Risk Individuals

Introduction: Chromosomal microarray analysis (CMA) allows the detection of submicroscopic chromosomal abnormalities such as unbalanced translocations and inversions. In recent years, its use in prenatal diagnosis has been implemented when certain ultrasound findings are detected. The purpose of this study was to analyze and describe the imbalances detected in prenatal samples collected from pregnancies followed in our center for having the indication to perform diagnosis using CMA. Material and Method: On a population of pregnant women of 13,685, 216 CMAs were performed on chorionic villi and amniotic fluids during the period 2019–2023. The inclusion criteria were normal screening of common aneuploidies and at least one of the following features: nuchal translucency higher than percentile 99, fetal abnormalities, early-onset fetal growth restriction, parents’ history of chromosomal imbalances, or cases with chromosomal imbalances. When a relevant variant was detected, it was analyzed in the parents’ fetus and when available, the phenotype of the born children was collected. Results: Pathogenic copy number variations (CNVs) were detected in 13 of 216 samples (6%). In a single sample, two concurrent CNVs were detected. Isolated CNVs had OMIM numbers and corresponded to already reported syndromes. Seven variants of unknown significance (3.7%) were observed. The study of the parents showed that 14 of 21 variants identified had arisen de novo (one pathogenic and five unknown CNVs had been inherited from an apparently healthy parent). Three microduplications specially drew our attention: duplication 5q35.2 which encompassed MSX2 gene (because the reported phenotype is not consistent with what is expected for the genomic region) and duplications 1q21.1 and 16p11.2 (due to the ultrasound findings detected in fetuses had recently been postulated to be associated with these CNVs). Conclusion: The phenotype of CNVs identified in prenatal samples is highly variable prenatally, like postnatally. Some findings may be part of the syndromes to which they give rise and some phenotypes may be pending to define. Further studies are needed to better define these variants and to understand how haploinsufficiency or over-expression of genes included in these regions can cause such complex phenotypes.

Clinical and genetic analysis of a case with 2p23.2p22.1 duplication

To report on the phenotype of an adult patient with 2p23.2p22.1 duplication and explore its genotype-phenotype correlation. A pregnant woman who had presented at the Affiliated Drum Tower Hospital of Nanjing University Medical School on January 12, 2024 for a high risk signaled by NIPT was selected as the study subject. Amniotic fluid and peripheral blood samples were collected and subjected to chromosomal microarray analysis (CMA). The phenotype of the patient was observed, the medical history was taken, combined with the result of CMA assay, relevant database was searched for similar cases reported in the literature, and the correlation between genotype and phenotype was analyzed. The CMA result of the patient was arr[GRCh38]2p23.2p22.1(27961669_39280633)×3, which indicated a 11.31 Mb duplication. The woman was found to have short stature, learning disability, visual deficit, sleep disorder and other disorders. The duplication of PPP1CB and SOS1 genes within the 2p23.2p22.1 region can result in Noonan syndrome-like clinical manifestations such as short stature and reduced visual acuity. The duplication of the PPP1CB gene may be associated with the abnormal visual phenotype.

Comparison of chromosomal microarray and karyotyping in prenatal diagnosis using 491 amniotic fluid samples.

This study was aimed to investigate the performance of chromosomal microarray analysis (CMA) in prenatal diagnosis compared with traditional karyotyping analysis. Both CMA and karyotyping analyses were performed to detect the karyotypes in the amniotic fluid of 491 pregnant women who got prenatal diagnosis at the Center of Prenatal Diagnosis of Shangrao (China) during January 2019 to April 2021. After excluding 2 samples in the CMA analysis and 2 samples in the karyotyping analysis which were failed in detection, the remaining 487 amniotic fluid samples were detected. Both CMA and karyotyping analyses identified 22 cases of aneuploidy chromosome abnormalities, including trisomy 21 (10 cases), trisomy 18 (4 cases), sex chromosome abnormality (5 cases), and other chromosome abnormalities (3 cases). In addition, CMA and karyotyping analyses found 8 cases of fetal chromosomal imbalance. Interestingly, abnormal results were detected by CMA analysis in 10 cases whose results were normal by karyotype analysis. Furthermore, 23 cases of copy number variation (CNVs) with variation of unknown clinical significance (VOUS) were detected by CMA, which accounted for 4.68% (23/491) in all cases. However, CMA was not able to accurately identify some complex karyotypes and mixed chimeras, including 2 cases of chimeras, 4 cases of balanced translocations, 4 cases of pericentric inversions, and 8 cases of other chromosome polymorphisms, indicating karyotyping analysis was superior to detect these chromosome abnormalities compared with CMA analysis. CMA was better in detecting the fracture sites, microduplication and microdeletion with definite pathogenicity, and CNVs with VOUS compared with karyotype analysis.

Chromosomal Microarray in Children Born Small for Gestational Age - Single Center Experience.

The association between small for gestational age birth and chromosomal abnormalities identified through karyotyping is well-established. Notably, advancements in cytogenetic techniques have shifted from routine karyotyping to the recommended use of microarray technology. This transition allows higher resolution and the detection of sub-microscopic copy number variants (CNVs). Our study included 49 patients born small for gestational age, 27 males and 22 females. Clinical data were gathered from reports by clinical genetic specialists, and a questionnaire was included in the referral list to our laboratory. All participants were of pediatric age, ranging from neonatal to 12 years old. Chromosomal microarray testing was conducted by the Agilent SurePrint G3 Human CGH Microarray 8×60K. The application of molecular karyotyping yielded clinically significant results in 16 cases (32.65%), which included 13 deletions and 6 duplications. Three patients presented with two clinically significant CNVs (csCNVs). In ten cases, we identified recurrent microdeletion or microduplication syndromes well-documented in the literature: Williams syndrome as the most commonly identified (three patients), and others like Koolen de Vries, Prader-Willi, Miller-Dieker, Dryer, DiGeorge syndrome, 7q11.23 microduplication, 16p13.11 microdeletion, and 1q21.1 microdeletion syndrome. Six patients had rare non-recurrent pathological CNVs. There was no statistically significant difference between patients with csCNVs and those without regarding the presence of intellectual disabilities, central nervous system, cardiac or skeletal malformations. Chromosomal microarray proves to be a useful diagnostic tool in the etiology diagnosis of children born small for gestational age.