Papillary renal neoplasm with reverse polarity has low frequency of alterations in chromosomes 7, 17, and Y.

In papillary renal neoplasm with reverse polarity (PRNRP), the status of chromosomal copy number alterations, especially chromosomes 7/17 gain and chromosome Y loss, has remained controversial. In the literatures, there is a discrepancy among the results of chromosomal alteration in PRNRP depending on the analytical methods. Here, we comprehensively analyzed the status of chromosomal abnormalities in PRNRP. Nineteen PRNRP cases were analyzed by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), five of which were additionally subjected to array-based comparative genomic hybridization (aCGH) analysis. Fifteen cases of PRCC were used as controls. From the aCGH results, no genome copy number abnormalities were found in the five PRNRP cases. By FISH, numbers of nuclei with abnormal chromosomal signals in PRNRP (centromere 7 gain: 11-21% of nuclei, centromere 17 gain: 11% of nuclei, centromere Y loss: 14-31% of nuclei) were similar to those in non-neoplastic tubular cells (centromere 7 gain: 11-15% of nuclei, centromere 17 gain: 12-15% of nuclei, centromere Y loss: 13-45% of nuclei). c-MET immunohistochemical overexpression, a substitute marker for chromosome 7 trisomy, was observed in 0 of 19 PRNRP cases, consistent with the analyses by aCGH and NGS regarding chromosome 7 gain. Taken together, the frequency of chromosomal alterations in PRNRP is similar to that in non-neoplastic tubular cells, and lower than that in PRCC. Our data suggest that PRNRP has a different tumorigenesis and is a distinct entity from PRCC.

Technologies to Study Genetics and Molecular Pathways.

Over the last few decades, the study of congenital heart disease (CHD) has benefited from various model systems and the development of molecular biological techniques enabling the analysis of single gene as well as global effects. In this chapter, we first describe different models including CHD patients and their families, animal models ranging from invertebrates to mammals, and various cell culture systems. Moreover, techniques to experimentally manipulate these models are discussed. Second, we introduce cardiac phenotyping technologies comprising the analysis of mouse and cell culture models, live imaging of cardiogenesis, and histological methods for fixed hearts. Finally, the most important and latest molecular biotechniques are described. These include genotyping technologies, different applications of next-generation sequencing, and the analysis of transcriptome, epigenome, proteome, and metabolome. In summary, the models and technologies presented in this chapter are essential to study the function and development of the heart and to understand the molecular pathways underlying CHD.

An Unclassified Deletion Involving the Proximal Short Arm of Chromosome 10: A New Syndrome?

To date, only 13 studies have described patients with large overlapping deletions of 10p11.2-p12. These individuals shared a common phenotype characterized by intellectual disability, developmental delay, distinct facial dysmorphic features, abnormal behaviour, visual impairment, cardiac malformation, and cryptorchidism in males. Molecular cytogenetic analysis revealed that the deletion in this chromosomal region shares a common smallest region of overlap (SRO) of 80 kb, which contains only the WAC gene (WW-domain-containing adaptor with coiled coil). In this clinical case report, we report a 5-year-old girl, born from non-consanguineous parents, with a 10p11.22p11.21 microdeletion. She presents clinical features that overlap with other patients described in the literature, such as dysmorphic traits, speech delay, and behavioural abnormalities (hyperactivity), even though the WAC gene is not involved in the microdeletion. Our results are the first to highlight that the deletion described here represents a contiguous gene syndrome that is enough to explain the distinct phenotype but partially overlaps with the previous cases reported in the literature, even though the same genes are not involved. In particular, in this study, we speculate about the role of the WAC gene that seems to be associated with normal motor development. In fact, we found that our patient is the only one described in the literature with a large deletion in the 10p11.22p11.21 region without the involvement of the WAC gene deletion, and, interestingly, the patient did not have motor delay.

Identification of a rare copy number polymorphic gain at 3q12.2 with candidate genes for familial endometriosis.

Endometriosis is a complex disease that affects 10-15% of women of reproductive age. Familial studies show that relatives of affected patients have a higher risk of developing the disease, implicating a genetic role for this disorder. Little is known about the impact of germline genomic copy number variant (CNV) polymorphisms on the heredity of the disease. In this study, we describe a rare CNV identified in two sisters with familial endometriosis, which contain genes that may increase the susceptibility and progression of this disease. We investigated the presence of CNVs from the endometrium and blood of the sisters with endometriosis and normal endometrium of five women as controls without the disease using array-CGH through the Agilent 2x400K platform. We excluded common CNVs that were present in the database of genomic variation. We identified, in both sisters, a rare CNV gain affecting 113kb at band 3q12.2 involving two candidate genes: ADGRG7 and TFG. The CNV gain was validated by qPCR. ADGRG7 is located at 3q12.2 and encodes a G protein-coupled receptor influencing the NF-kappaß pathway. TFG participates in chromosomal translocations associated with hematologic tumor and soft tissue sarcomas, and is also involved in the NF-kappa B pathway. The CNV gain in this family provides a new candidate genetic marker for future familial endometriosis studies. Additional longitudinal studies of affected families must confirm any associations between this rare CNV gain and genes involved in the NF-kappaß pathway in predisposition to endometriosis.

Genetic Alterations in a Large Population of Italian Patients Affected by Neurodevelopmental Disorders.

Neurodevelopmental disorders are a group of complex multifactorial disorders characterized by cognitive impairment, communication deficits, abnormal behaviour, and/or motor skills resulting from abnormal neural development. Copy number variants (CNVs) are genetic alterations often associated with neurodevelopmental disorders. We evaluated the diagnostic efficacy of the array-comparative genomic hybridization (a-CGH) method and its relevance as a routine diagnostic test in patients with neurodevelopmental disorders for the identification of the molecular alterations underlying or contributing to the clinical manifestations. In the present study, we analysed 1800 subjects with neurodevelopmental disorders using a CGH microarray. We identified 208 (7%) pathogenetic CNVs, 2202 (78%) variants of uncertain significance (VOUS), and 504 (18%) benign CNVs in the 1800 patients analysed. Some alterations contain genes potentially related to neurodevelopmental disorders including CHRNA7, ANKS1B, ANKRD11, RBFOX1, ASTN2, GABRG3, SHANK2, KIF1A SETBP1, SNTG2, CTNNA2, TOP3B, CNTN4, CNTN5, and CNTN6. The identification of interesting significant genes related to neurological disorders with a-CGH is therefore an essential step in the diagnostic procedure, allowing a better understanding of both the pathophysiology of these disorders and the mechanisms underlying their clinical manifestations.

Cat eye syndrome: Clinical, cytogenetics and familial findings in a large cohort of 43 patients highlighting the importance of congenital heart disease and inherited cases.

Cat Eye Syndrome (CES) is a rare genetic disease caused by the presence of a small supernumerary marker chromosome derived from chromosome 22, which results in a partial tetrasomy of 22p-22q11.21. CES is classically defined by association of iris coloboma, anal atresia, and preauricular tags or pits, with high clinical and genetic heterogeneity. We conducted an international retrospective study of patients carrying genomic gain in the 22q11.21 chromosomal region upstream from LCR22-A identified using FISH, MLPA, and/or array-CGH. We report a cohort of 43 CES cases. We highlight that the clinical triad represents no more than 50% of cases. However, only 16% of CES patients presented with the three signs of the triad and 9% not present any of these three signs. We also highlight the importance of other impairments: cardiac anomalies are one of the major signs of CES (51% of cases), and high frequency of intellectual disability (47%). Ocular motility defects (45%), abdominal malformations (44%), ophthalmologic malformations (35%), and genitourinary tract defects (32%) are other frequent clinical features. We observed that sSMC is the most frequent chromosomal anomaly (91%) and we highlight the high prevalence of mosaic cases (40%) and the unexpectedly high prevalence of parental transmission of sSMC (23%). Most often, the transmitting parent has mild or absent features and carries the mosaic marker at a very low rate (<10%). These data allow us to better delineate the clinical phenotype associated with CES, which must be taken into account in the cytogenetic testing for this syndrome. These findings draw attention to the need for genetic counseling and the risk of recurrence.

Outcome of partial agenesis of corpus callosum.

BACKGROUND: The diagnosis of corpus callosum anomalies by prenatal ultrasound has improved over the last decade because of improved imaging techniques, scanning skills, and the routine implementation of transvaginal neurosonography. OBJECTIVE: Our aim was to investigate all cases of incomplete agenesis of the corpus callosum and to report the sonographic characteristics, the associated anomalies, and the perinatal outcomes. STUDY DESIGN: We performed a retrospective analysis of cases from January 2007 to December 2017 with corpus callosum anomalies, either referred for a second opinion or derived from the prenatal ultrasound screening program in a single tertiary referral center. Cases with complete agenesis were excluded from the analysis. Standardized investigation included a detailed fetal ultrasound including neurosonogram, fetal karyotyping (standard karyotype or array comparative genomic hybridization) and fetal magnetic resonance imaging. The pregnancy outcome was collected, and pathologic investigation in case of termination of the pregnancy or fetal or neonatal loss was compared with the prenatal findings. The pregnancy and fetal or neonatal outcomes were reported. The neurologic assessment was conducted by a pediatric neurologist using the Bayley Scales of Infant Development-II and the standardized Child Development Inventory when the Bayley investigation was unavailable. RESULTS: Corpus callosum anomalies were diagnosed in 148 cases during the study period, 62 (41.9%) of which were excluded because of complete agenesis, and 86 fetuses had partial agenesis (58.1%). In 20 cases, partial agenesis (23.2%) was isolated, whereas 66 (76.7%) presented with different malformations among which 29 cases (43.9%) were only central nervous system lesions, 21 cases (31.8%) were non-central nervous system lesions, and 16 cases (24.3%) had a combination of central nervous system and non-central nervous system lesions. The mean gestational age at diagnosis for isolated and non-isolated cases was comparable (24.29 [standard deviation, 5.05] weeks and 24.71 [standard deviation, 5.35] weeks, respectively). Of the 86 pregnancies with partial agenesis, 46 patients opted for termination of the pregnancy. Neurologic follow-up data were available for 35 children. The overall neurologic outcome was normal in 21 of 35 children (60%); 3 of 35 (8.6%) showed mild impairment and 6 of 35 (17.1%) showed moderate impairment. The remaining 5 of 35 (14.3%) had severe impairment. The median duration of follow-up for the isolated form was 45.6 months (range, 36-52 months) and 73.3 months (range, 2-138 months) for the nonisolated form. CONCLUSION: Partial corpus callosum agenesis should be accurately investigated by neurosonography and fetal magnetic resonance imaging to describe its morphology and the associated anomalies. Genetic anomalies are frequently present in nonisolated cases. Efforts must be taken to improve ultrasound diagnosis of partial agenesis and to confirm its isolated nature to enhance parental counseling. Although 60% of children with prenatal diagnosis of isolated agenesis have a favorable prognosis later in life, they often have mild to severe disabilities including speech disorders at school age and behavior and motor deficit disorders that can emerge at a later age.

Identification of a rare copy number polymorphic gain at 3q12.2 with candidate genes for familial endometriosis

Abstract Endometriosis is a complex disease that affects 10-15% of women of reproductive age. Familial studies show that relatives of affected patients have a higher risk of developing the disease, implicating a genetic role for this disorder. Little is known about the impact of germline genomic copy number variant (CNV) polymorphisms on the heredity of the disease. In this study, we describe a rare CNV identified in two sisters with familial endometriosis, which contain genes that may increase the susceptibility and progression of this disease. We investigated the presence of CNVs from the endometrium and blood of the sisters with endometriosis and normal endometrium of five women as controls without the disease using array-CGH through the Agilent 2x400K platform. We excluded common CNVs that were present in the database of genomic variation. We identified, in both sisters, a rare CNV gain affecting 113kb at band 3q12.2 involving two candidate genes: ADGRG7 and TFG. The CNV gain was validated by qPCR. ADGRG7 is located at 3q12.2 and encodes a G protein-coupled receptor influencing the NF-kappaβ pathway. TFG participates in chromosomal translocations associated with hematologic tumor and soft tissue sarcomas, and is also involved in the NF-kappa B pathway. The CNV gain in this family provides a new candidate genetic marker for future familial endometriosis studies. Additional longitudinal studies of affected families must confirm any associations between this rare CNV gain and genes involved in the NF-kappaβ pathway in predisposition to endometriosis.

Array-comparative genomic hybridization analysis in a cohort of 130 children with Autism Spectrum Disorders: A single Center Italian Study.

Introduction: utism spectrum disorder (ASD) is a heterogeneous clinical condition, and its genetic basis is widely confirmed. The chromosomal microarray analysis (CMA) is a first-line diagnostic test that identifies copy number variants (CNVs). Some of these genomic rearrangements are associated with ASD, but the meaning of most of them is still unknown. Materials and methods: We performed a comparative genome hybridization (array-CGH) analysis in 130 children with confirmed ASD. Genetic results were analyzed and compared to clinical phenotype. Results and discussion.: 61/130 children carry CNVs, 44 presenting variants of unknown significance (u-CNVs), and 17 with susceptibility-CNVs (c-CNVs). Clinical evaluation showed no differences in cognitive abilities, language and EEG abnormalities, ASD symptoms among CNVs group and other patients. Finally, we highlight the role of GPHN, IMMP2L and ZMYND11, as ASD susceptibility genes. Conclusions: Our findings underscore the importance of array-CGH in ASD children since new CNVs and emerging genes appear to be associated with different clinical pictures.

TRAPPC9-Related Intellectual Disability: Report of Two New Cases and Review of the Literature.

Introduction: Hereditary forms of intellectual disability (ID), an estimated prevalence ranging between 1% and 3% in the general population, are among the most important problems in health care. Especially, autosomal-recessive ID has a very heterogeneous molecular basis and a lack of specific phenotypic features. Methods: Here, we report on two unrelated patients with autosomal-recessive ID, microcephaly, and autistic features and review the patients with TRAPPC9-related ID. Whole-exome sequencing and array CGH were performed for molecular diagnosis of the patients. Results: The first case has a microdeletion on chromosome 8q24.23-q24.3 region which is 1.7 Mb in length and includes the last 5 exons of TRAPPC9, and c.3435delG [p.Thr1146Profs*8] deletion. The second case has a homozygous missense c.623A>C (p.His208Pro) variant in TRAPPC9 which is detected by means of whole-exome sequencing study of the proband. We also reviewed the clinical findings and mutation spectrum of all patients with TRAPPC9-related ID reported so far. Conclusions: Our study showed that the most consistent clinical findings for TRAPPC9-related ID are ID, microcephaly, and some structural brain MRI abnormalities. The mutations in the TRAPPC9 are scattered throughout all exons of TRAPPC9 indicating there is no hot spot mutation region in this gene.

Primary biliary cholangitis with features of autoimmune hepatitis in a 19-year-old adolescent with 14q24.1q24.2 deletion: a case report.

Introduction: Primary biliary cholangitis (PBC) is a rare and chronic autoimmune liver disease characterized by the progressive destruction of small intrahepatic bile ducts that may eventually lead to cirrhosis. PBC with features of autoimmune hepatitis (AIH) has rarely been reported in pediatric patients with genetic defects. We present the case of an adolescent with chromosome 14q24.1q24.2 deletion who was given the diagnosis of stage IV PBC with features of AIH. Case presentation: A 19-year-old male adolescent with multiple congenital abnormalities and an intellectual disability presented with abnormal liver enzymes levels and pruritus for more than 5 years. Laboratory examinations revealed elevated levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma-glutamyl transpeptidase. After the exclusion of viral hepatitis, alpha-1 antitrypsin deficiency, Wilson's disease, and other genetic cholestatic liver diseases by laboratory tests and whole exome sequencing, a liver biopsy was performed and stage IV PBC was diagnosed. Notably, features of AIH were also noted in the histopathological report, indicating the presence of PBC with AIH features. The patient responded well to a combination therapy of ursodeoxycholic acid and steroids. Array comparative genomic hybridization analysis performed to study the congenital abnormalities revealed a 3.89 Mb 14q24.1q24.2 deletion. Conclusion: PBC with AIH features has rarely been reported in an adolescent with a chromosomal abnormality. The present case can increase awareness for early-onset PBC and its possible correlation with chromosomal defects.

A Case Report of SYNE1 Deficiency-Mimicking Mitochondrial Disease and the Value of Pangenomic Investigations.

Mitochondrial disorders are characterized by a huge clinical, biochemical, and genetic heterogeneity, which poses significant diagnostic challenges. Several studies report that more than 50% of patients with suspected mitochondrial disease could have a non-mitochondrial disorder. Thus, only the identification of the causative pathogenic variant can confirm the diagnosis. Herein, we describe the diagnostic journey of a family suspected of having a mitochondrial disorder who were referred to our Genetics Department. The proband presented with the association of cerebellar ataxia, COX-negative fibers on muscle histology, and mtDNA deletions. Whole exome sequencing (WES), supplemented by a high-resolution array, comparative genomic hybridization (array-CGH), allowed us to identify two pathogenic variants in the non-mitochondrial SYNE1 gene. The proband and her affected sister were found to be compound heterozygous for a known nonsense variant (c.13258C>T, p.(Arg4420Ter)), and a large intragenic deletion that was predicted to result in a loss of function. To our knowledge, this is the first report of a large intragenic deletion of SYNE1 in patients with cerebellar ataxia (ARCA1). This report highlights the interest in a pangenomic approach to identify the genetic basis in heterogeneous neuromuscular patients with the possible cause of mitochondrial disease. Moreover, even rare copy number variations should be considered in patients with a phenotype suggestive of SYNE1 deficiency.

The challenges in the interpretation of genetic variants detected by genomics techniques in patients with congenital anomalies.

BACKGROUND: Despite the efforts that have been made to standardize the interpretation of variants, in some cases, their pathogenicity remains vague and confusing, and sometimes their interpretation does not help clinicians to establish clinical correlation using genetic test results. This study aims to shed more lights on these challenging variants. METHODS: In a clinical setting, the variants found from 81 array CGH and 79 whole exome sequencing (WES) in patients with congenital anomalies were interpreted based on American College of Medical Genetics and Genomics guidelines. RESULTS: In this study, the interpretation of the disease-causing variants and the variants with uncertain clinical significance detected by WES was far more challenging than the variants detected by array CGH. The presence of unreported clinical symptoms, incomplete penetrance, variable expressivity, parents' reluctance to analyze segregation in the family, and the limitations of prenatal tests, were among the challenging factors in the interpretation of variants in this study. CONCLUSION: A careful study of the pedigree and disease mode of inheritance, as well as a careful clinical examination of the carrier parents in diseases with autosomal dominant inheritance, are among the primary strategies for determining the clinical significance of the variants. Continued efforts to mitigate these challenges are needed to improve the interpretation of variants.

Genomic Complexity and Complex Chromosomal Rearrangements in Genetic Diagnosis: Two Illustrative Cases on Chromosome 7.

Complex chromosomal rearrangements are rare events compatible with survival, consisting of an imbalance and/or position effect of one or more genes, that contribute to a range of clinical presentations. The investigation and diagnosis of these cases are often difficult. The interpretation of the pattern of pairing and segregation of these chromosomes during meiosis is important for the assessment of the risk and the type of imbalance in the offspring. Here, we investigated two unrelated pediatric carriers of complex rearrangements of chromosome 7. The first case was a 2-year-old girl with a severe phenotype. Conventional cytogenetics evidenced a duplication of part of the short arm of chromosome 7. By array-CGH analysis, we found a complex rearrangement with three discontinuous trisomy regions (7p22.1p21.3, 7p21.3, and 7p21.3p15.3). The second case was a newborn investigated for hypodevelopment and dimorphisms. The karyotype analysis promptly revealed a structurally altered chromosome 7. The array-CGH analysis identified an even more complex rearrangement consisting of a trisomic region at 7q11.23q22 and a tetrasomic region of 4.5 Mb spanning 7q21.3 to q22.1. The mother's karyotype examination revealed a complex rearrangement of chromosome 7: the 7q11.23q22 region was inserted in the short arm at 7p15.3. Finally, array-CGH analysis showed a trisomic region that corresponds to the tetrasomic region of the son. Our work proved that the integration of several technical solutions is often required to appropriately analyze complex chromosomal rearrangements in order to understand their implications and offer appropriate genetic counseling.

A Case of Class I 17p13.3 Microduplication Syndrome with Unilateral Hearing Loss.

17p13 is a chromosomal region characterized by genomic instability due to high gene density leading to multiple deletion and duplication events. 17p13.3 microduplication syndrome is a rare condition, reported only in 40 cases worldwide, which is found in the Miller-Dieker chromosomal region, presenting a wide range of phenotypic manifestations. Usually, the duplicated area is de novo and varies in size from 1.8 to 4.0 Mbp. Critical genes for this region are PAFAH1B1 (#601545), YWHAE (#605066), and CRK (#164762). 17p13.3 microduplication syndrome can be categorized into two classes (Class I and Class II) based on the genes that are present in the duplicated area, which lead to different phenotypes. In this report, we present a new case of Class I 17p13.3 microduplication syndrome that presents with unilateral sensorineural hearing loss. Oligonucleotide and SNP array comparative genomic hybridization (a-CGH) analysis revealed a duplication of approximately 121 Kbp on chromosome 17p13.3, which includes YWHAE and CRK genes. Whole-exome sequencing (WES) analysis confirmed the duplication. Our patient has common clinical symptoms of Class I 17p13.3 microduplication syndrome, and in addition, she has unilateral sensorineural hearing loss. Interestingly, WES analysis did not detect any mutations in genes that are associated with hearing loss. The above findings lead us to propose that hearing loss is a manifestation of 17p13.3 duplication syndrome.

APC-Related Phenotypes and Intellectual Disability in 5q Interstitial Deletions: A New Case and Review of the Literature.

The 5q deletion syndrome is a relatively rare condition caused by the monoallelic interstitial deletion of the long arm of chromosome 5. Patients described in literature usually present variable dysmorphic features, behavioral disturbance, and intellectual disability (ID); moreover, the involvement of the APC gene (5q22.2) in the deletion predisposes them to tumoral syndromes (Familial Adenomatous Polyposis and Gardner syndrome). Although the development of gastrointestinal tract malignancies has been extensively described, the genetic causes underlying neurologic manifestations have never been investigated. In this study, we described a new patient with a 19.85 Mb interstitial deletion identified by array-CGH and compared the deletions and the phenotypes reported in other patients already described in the literature and the Decipher database. Overlapping deletions allowed us to highlight a common region in 5q22.1q23.1, identifying KCNN2 (5q22.3) as the most likely candidate gene contributing to the neurologic phenotype.

AhRR and PPP1R3C: Potential Prognostic Biomarkers for Serous Ovarian Cancer.

The lack of effective screening and successful treatment contributes to high ovarian cancer mortality, making it the second most common cause of gynecologic cancer death. Development of chemoresistance in up to 75% of patients is the cause of a poor treatment response and reduced survival. Therefore, identifying potential and effective biomarkers for its diagnosis and prognosis is a strong critical need. Copy number alterations are frequent in cancer, and relevant for molecular tumor stratification and patients' prognoses. In this study, array-CGH analysis was performed in three cell lines and derived cancer stem cells (CSCs) to identify genes potentially predictive for ovarian cancer patients' prognoses. Bioinformatic analyses of genes involved in copy number gains revealed that AhRR and PPP1R3C expression negatively correlated with ovarian cancer patients' overall and progression-free survival. These results, together with a significant association between AhRR and PPP1R3C expression and ovarian cancer stemness markers, suggested their potential role in CSCs. Furthermore, AhRR and PPP1R3C's increased expression was maintained in some CSC subpopulations, reinforcing their potential role in ovarian cancer. In conclusion, we reported for the first time, to the best of our knowledge, a prognostic role of AhRR and PPP1R3C expression in serous ovarian cancer.

Dicentric Recombinant Chromosome 18 due to Maternal Paracentric Inversion Analyzed by Array CGH.

Introduction: Chromosomal abnormalities are mostly found in 0.5-0.8% of live-born infants with developmental and morphological defects. Paracentric inversions are structural intrachromosomal rearrangements resulting in a risk of chromosomally unbalanced gametes in carriers. Case Presentation: Herein, we report a patient with dicentric rearrangement of chromosome 18 due to maternal paracentric inversion of chromosome 18. The patient was a girl, aged 3 years and 11 months. She was referred due to multiple congenital abnormalities, severe intellectual disability, and motor retardation. She had microcephaly, prominent metopic suture, synophrys, epicanthic folds, telecanthus, wide-set alae nasi, wide columella, bilateral cleft lip and palate, pectus carinatum, umbilical hernia, pes planus, and anteriorly displaced anus. She had bilateral external auditory canal stenosis and mild right-sided and moderate left-sided sensorineural hearing loss. Echocardiography showed secundum-type atrial septal defect and mild tricuspid failure. Brain magnetic resonance imaging showed only thinning of posterior areas of the corpus callosum. Chromosome analysis showed 46,XX,dic rec(18) by GTG and C banding. Dicentric chromosome was confirmed by fluorescence in situ hybridization analysis. Paternal karyotype was normal 46,XY but maternal chromosome analysis showed a paracentric inversion in chromosome 18 with 46,XX,inv(18)(q11.2?q21.3?) karyotype. Array CGH was performed on a peripheral blood sample from the patient and showed duplication at 18p11.32p11.21 and 18q11.1q11.2, and deletion at 18q21.33q23. The patient's final karyotype is arr 18p11.32p11.21(64,847_15,102,598)×3,18q11.1q11.2(18,542,074_22,666,470)×3,18q21.33q23(59,784,364_78,010,032)×1. Discussion: To the best of our knowledge, this is the first report of a patient with dicentric chromosome 18 due to a parental paracentric inversion of chromosome 18. We present the genotype-phenotype correlation with literature review.

7p22.2 Microduplication: A Pathogenic CNV?

Partial duplication of the short arm of chromosome 7 is a rare chromosome rearrangement. The phenotype spectrum associated with this rearrangement is extremely variable even if in the last decade the use of high-resolution microarray technology for the investigation of patients carrying this rearrangement allowed for the identification of the 7p22.1 sub-band causative of this phenotype and to recognize the corresponding 7p22.1 microduplication syndrome. We report two unrelated patients that carry a microduplication involving the 7.22.2 sub-band. Unlike 7p22.1 microduplication carriers, both patients only show a neurodevelopmental disorder without malformations. We better characterized the clinical pictures of these two patients providing insight into the clinical phenotype associated with the microduplication of the 7p22.2 sub-band and support for a possible role of this sub-band in the 7p22 microduplication syndrome.