CAPRIN1 gene encodes a RNA-binding protein, abundant in the brain where it plays a crucial role, regulating the transport and translation of mRNAs of synaptic proteins.CAPRIN1 haploinsufficiency causes a neurodevelopmental disorder characterized by language impairment/speech delay, intellectual disability, attention deficit, hyperactivity disorder, and autism spectrum disorder. To understand the pathogenesis of this disorder and in view of future treatment, we generated human induced pluripotent stem cells (iPSCs) from a patient carrying the c.1744C>T CAPRIN1 variant. The line show marker expression for the pluripotency and the capacity to differentiate into the three germ layers.

Background/Objectives: CLIFAHDD syndrome (OMIM # 616266) is a rare neurodevelopmental disorder caused by mutations in the NALCN gene. It is characterized by hypotonia, developmental delay, and congenital contractures of the limbs and face. We report a 33-year-old Italian woman with a mild form of CLIFAHDD who exhibited early-onset language difficulties and mild intellectual disability and later developed gait and balance impairments in adulthood. Methods and Results: Whole Exome Sequencing (WES) identified a novel missense variant c.1514A>T; p.(Lys505Met) in the NALCN gene. The allele frequency of this variant is not detected (MAF = 0.0), the variant is classified as likely pathogenic according to ACMG criteria, and predicted to be probably damaging by PolyPhen-2. It affects a critical residue within the second pore-forming domain of the NALCN channel, potentially altering lipid interactions and channel regulation. Sanger sequencing and segregation analysis confirmed the variant to be heterozygous and de novo. Conclusions: The patient’s milder symptoms and later onset, compared to severe pediatric cases, suggest that the clinical spectrum of CLIFAHDD syndrome may be broader than previously recognized. These findings underscore the potential influence of mutation location on disease presentation and severity.

Salivary gland pleomorphic adenoma (SGPA) is the most common type of benign epithelial tumor; it is observed more commonly in females (with a female-to-male ratio of 1.43:1), and the age at diagnosis ranges between 40 and 59 years, with only 2% of cases diagnosed before age 18. Cri du Chat (CdC) is a rare syndrome caused by deletions of various sizes in the short arm of chromosome 5. Tumors in CdC patients are extremely rare: in Danish, Spanish, Australian, and Japanese groups of cases, no tumors have been reported, while a few cases have been described among 321 CdC patients collected in Italy and Germany. These cases all involve tumors that appear at a young age. We here report the case of a parotid pleomorphic adenoma in an 8-year-old boy with CdC. Exome analysis did not identify variants certainly significant for the development of SGPA. A CGH array, analyzed both in peripheral blood and tumor samples, failed to recognize anomalies previously associated with SGPA but identified a de novo duplication in 7p15.2, which contains part of a gene, SKAP2, in which the increased copy number is associated with the development of a different type of tumor such as pancreatic duct adenocarcinoma. The assumption that the duplication in 7p15.2 is relevant for the development of SGPA in our patient implies that CGH array studies must be included early in life in routine work-ups of CdC to identify CNVs with possible pathogenic roles for tumor development. This is particularly also relevant in relation to the severely impaired possibility for patients with CdC to report discomfort or pain related to tumor development. Constitutional CNVs in addition to the deletion in 5p should also be extensively studied to verify if their presence in some patients could explain why, in these cases, tumors develop at an age younger than expected.

Sotos syndrome (SoS) is a neurodevelopmental disorder that results from NSD1 mutations that cause haploinsufficiency of NSD1. Here, we generated an induced pluripotent stem cell (iPSC) line from fibroblasts of a SoS patient carrying the pathogenic variant (c.1633delA). The cell line shows typical iPSC morphology, high expression of pluripotent markers, normal karyotype, and it differentiates into three germ layers in vitro. This line is a valuable resource for studying pathological pathways involved in SoS.

Germline variants in the NSD1 gene are responsible for Sotos syndrome, while somatic variants promote neoplastic cell transformation. Our previous studies revealed three alternative RNA isoforms of NSD1 present in fibroblast cell lines (FBs): the canonical full transcript and 2 alternative transcripts, termed AT2 (NSD1 Δ5Δ7) and AT3 (NSD1 Δ19–23 at the 5′ end). The precise molecular pathways affected by each specific isoform of NSD1 are uncharacterized to date. To elucidate the role of these isoforms, their expression was suppressed by siRNA knockdown in FBs and protein expression and transcriptome data was explored. We demonstrate that one gene target of NSD1 isoform AT2 is ARP3 actin-related protein 3 homolog B (ACTR3B). We show that loss of both canonical NSD1 and AT2 isoforms impaired the ability of fibroblasts to regulate the actin cytoskeleton, and we observed that this caused selective loss of stress fibers. Our findings provide novel insights into NSD1 function by distinguishing isoform function and demonstrating an essential role of NSD1 in regulating the actin cytoskeleton and stress fiber formation in fibroblasts.

American Journal of Medical Genetics Part AVolume 191, Issue 7 p. 1681-1686 ISSUE INFORMATIONFree Access Table of Contents, Volume 191A, Number 7, July 2023 First published: 07 June 2023 https://doi.org/10.1002/ajmg.a.62813AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Volume191, Issue7July 2023Pages 1681-1686 RelatedInformation

NSD1 gene (Nuclear Receptor Binding SET Domain Protein 1) encodes a methyltransferase that plays an important role in embryonic development. NSD1 is implicated in the transcription and methylation of histone H3 at lysine 36 (H3-K36), but the molecular mechanisms involved in these processes remain largely unknown. Pathogenic variants of NSD1 gene lead to Sotos syndrome, and have also been detected in some type of cancers, such as acute myeloid leukemia. In this study we have investigated NSD1 mRNA expression in fibroblast cell lines obtained from 14 Sotos patients and from 8 healthy controls. In addition to the expected NSD1 canonical transcript (isoform 1), we identified two additional, not yet reported, short NSD1 mRNA isoforms: NSD1 Delta 5 Delta 7 (isoform 2) and NSD1 Delta 19-23 (isoform 3), both in healthy subjects and in Sotos patients. We also show that NSD1 mutations in patients can be associated with a decreased level of NSD1 mRNA, as expected. Moreover, one patient, bearing the NSD1 variant c.6010-10G > A, expressed an additional shorter transcript derived from an aberrant splicing event. These results may provide a basis to elucidate the impact of different NSD1 pathogenic variants on the het-erogeneity of phenotype associated with Sotos syndrome.

Sotos syndrome (SoS) is a congenital overgrowth syndrome with variable degree of intellectual disability caused in the 90% of cases by pathogenetic variants of the Nuclear receptor binding SET Domain protein1 (NSD1) gene. NSD1 gene functions can be abrogated by different genetic alterations (i.e., small intragenic pathogenic variants like deletions/insertions, nonsense/missense pathogenic variants, partial gene deletions and whole deletions or microdeletion of 5q35 chromosomal region). Therefore, correlation of the genotype-phenotype with a possible contribution of more implicated genes to the medical, cognitive and behavioral profile is a topic of great interest. Although a more severe learning disability has been described in individuals with 5q35 microdeletion when compared to individuals with NSD1 intragenic pathogenic variants a fully delineated cognitive and behavioral phenotype has not been described yet. The importance of providing clinical characterization in relation to the genotype comes from the necessity to early identify children more at risk of developing psychopathological disorders. We characterize the cognitive, adaptive and behavioral phenotype of a pediatric sample of 64 individuals affected by SoS, performing a standardized neuropsychological evaluation. Secondly, we compare cognitive-behavioral profiles of SoS individuals carrying and not carrying the 5q35 microdeletion. SoS participants were characterized by a mild cognitive impairment of both Intellectual Quotient and adaptive skills in association to borderline symptoms of attention deficit. Our results suggest that the 5q35 microdeletion is associated with lower scores specifically concerning the cognitive, adaptive functioning and behavioral domains. However, longitudinal studies are necessary to confirm these findings and delineate a developmental trajectory of SoS.

Sotos syndrome is a rare genetic disorder caused by haploinsufficiency of the NSD1 (nuclear receptor binding SET domain containing protein 1) gene. No clinical diagnostic consensus criteria are published yet, and molecular analysis reduces the clinical diagnostic uncertainty. We screened 1530 unrelated patients enrolled from 2003 to 2021 at Galliera Hospital and Gaslini Institute in Genoa. NSD1 variants were identified in 292 patients including nine partial gene deletions, 13 microdeletions of the entire NSD1 gene, and 115 novel intragenic variants never previously described. Thirty-two variants of uncertain significance (VUS) out of 115 identified were re-classified. Twenty-five missense NSD1 VUS (25/32, 78.1%) changed class to likely pathogenic or likely benign, showing a highly significant shift in class (p < 0.01). Apart from NSD1, we identified variants in additional genes (NFIX, PTEN, EZH2, TCF20, BRWD3, PPP2R5D) in nine patients analyzed by the NGS custom panel. We describe the evolution of diagnostic techniques in our laboratory to ascertain molecular diagnosis, the identification of 115 new variants, and the re-classification of 25 VUS in NSD1. We underline the utility of sharing variant classification and the need to improve communication between the laboratory staff and the referring physician.

Sotos syndrome (SoS) is a neurodevelopmental disorder caused by haploinsufficiency of the NSD1 gene located on chromosome 5 region q35.3. In order to understand the pathogenesis of Sotos syndrome and in view of future therapeutic approaches for its efficient treatment, we generated two human induced pluripotent stem cells (iPSCs) lines from one SoS patient carrying a 5q35 microdeletion. The established iPSCs expressed pluripotency markers, showing the capacity to differentiate into the three germ layers.

The CC2D2A gene is essential for primary cilia formation, and its disruption has been associated with Joubert Syndrome-9 (JBTS9), a ciliopathy with typical neurodevelopmental features. Here, we describe an Italian pediatric patient with typical features of Joubert Syndrome (JBTS): "Molar Tooth Sign", global developmental delay, nystagmus, mild hypotonia, and oculomotor apraxia. Whole exome sequencing and segregation analysis identified in our infant patient a novel heterozygous germline missense variant c.3626C > T; p.(Pro1209Leu) inherited from the father and a novel 7.16 kb deletion inherited from the mother. To the best of our knowledge, this is the first report showing a novel missense and deletion variant involving exon 30 of the CC2D2A gene.

An increasing amount of evidence indicates the critical role of the NSD1 gene in Sotos syndrome (SoS), a rare genetic disease, and in tumors. Molecular mechanisms affected by NSD1 mutations are largely uncharacterized. In order to assess the impact of NSD1 haploinsufficiency in the pathogenesis of SoS, we analyzed the gene expression profile of fibroblasts isolated from the skin samples of 15 SoS patients and of 5 healthy parents. We identified seven differentially expressed genes and five differentially expressed noncoding RNAs. The most upregulated mRNA was stratifin (SFN) (fold change, 3.9, Benjamini–Hochberg corrected p < 0.05), and the most downregulated mRNA was goosecoid homeobox (GSC) (fold change, 3.9, Benjamini–Hochberg corrected p < 0.05). The most upregulated lncRNA was lnc-C2orf84-1 (fold change, 4.28, Benjamini–Hochberg corrected p < 0.001), and the most downregulated lncRNA was Inc-C15orf57 (fold change, −0.7, Benjamini–Hochberg corrected p < 0.05). A gene set enrichment analysis reported the enrichment of genes involved in the KRAS and E2F signaling pathways, splicing regulation and cell cycle G2/M checkpoints. Our results suggest that NSD1 is involved in cell cycle regulation and that its mutation can induce the down-expression of genes involved in tumoral and neoplastic differentiation. The results contribute to defining the role of NSD1 in fibroblasts for the prevention, diagnosis and control of SoS.

Background Breast cancer (BC) is the most commonly diagnosed cancer and the second leading cause of cancer-related deaths among women in Africa after cervical cancer. Even if the epidemiological data are now aligned with those relating to industrialized countries, the knowledge concerning breast cancer in Africa, particularly in Western Africa, still lack clinical data, medical treatments, and the evaluation of genetic and non-genetic factors implicated in the etiology of the disease. The early onset and the aggressiveness of diagnosed breast cancers in patients of African ancestry strongly suggest that the genetic risk factor may be a key component, but so far, very few studies on the impact of germ line mutations in breast cancer in Africa have been conducted, with negative consequences on prevention, awareness and patient management. Through Next Generation sequencing (NGS), we analyzed all of the coding regions and the exon-intron junctions of BRCA1 and BRCA2 genes-the two most important genes in hereditary breast cancer-in fifty-one women from Burkina Faso with early onset of breast cancer with or without a family history. Results We identified six different pathogenic mutations (three in BRCA1, three in BRCA2), two of which were recurrent in eight unrelated women. Furthermore, we identified, in four other patients, two variants of uncertain clinical significance (VUS) and two variants never previously described in literature, although one of them is present in the dbSNP database. Conclusions This is the first study in which the entire coding sequence of BRCA genes has been analyzed through Next Generation Sequencing in Burkinabe young women with breast cancer. Our data support the importance of genetic risk factors in the etiology of breast cancer in this population and suggest the necessity to improve the genetic cancer risk assessment. Furthermore, the identification of the most frequent mutations of BRCA1 and BRCA2 in the population of Burkina Faso will allow the development of an inexpensive genetic test for the identification of subjects at high genetic cancer risk, which could be used to design personalized therapeutic protocols.

In the recent years the rapid scientific innovation in the evaluation of the individual’s genome have allowed the identification of variants associated with the onset, treatment and prognosis of various pathologies including cancer, and with a potential impact in the assessment of therapy responses. Despite the analysis and interpretation of genomic information is considered incomplete, in many cases the identification of specific genomic profile has allowed the stratification of subgroups of patients characterized by a better response to drug therapies. Individual genome analysis has changed profoundly the diagnostic and therapeutic approach of breast cancer in the last 15 years by identifying selective molecular lesions that drive the development of neoplasms, showing that each tumor has its own genomic signature, with some specific features and some features common to several sub-types. Several personalized therapies have been (and still are being) developed showing a remarkable efficacy in the treatment of breast cancer.