Prevalence of karyotype alterations in couples with recurrent pregnancy loss in a tertiary center in Brazil

Abstract Objective To assess the prevalence and type of chromosomal abnormalities in Brazilian couples with recurrent pregnancy loss (RPL) and compare the clinical characteristics of couples with and without chromosome abnormalities. Methods We assessed the medical records of 127 couples with a history of two or more miscarriages, referred to a tertiary academic hospital in Belo Horizonte, Brazil, from January 2014 to May 2023. Karyotype was generated from peripheral blood lymphocyte cultures, and cytogenetic analysis was performed according to standard protocols by heat-denatured Giemsa (RHG) banding. Results Abnormal karyotypes were detected in 10 couples (7.8%). The prevalence of chromosomal abnormalities was higher among females (6.3%) compared to males (2.0%), but this difference was not statistically significant (p=0.192). The mean number of miscarriages was. 3.3 ± 1.1 in couples with chromosome abnormalities and 3.1 ± 1.5 in couples without chromosome abnormalities (p=0.681). Numerical chromosomal anomalies (6 cases) were more frequent than structural anomalies. Four women presented low-grade Turner mosaicism. No differences were found between couples with and without karyotype alterations, except for maternal age, which was higher in the group with chromosome alterations. Conclusion The prevalence of parental chromosomal alterations in our study was higher than in most series described in the literature and was associated with increased maternal age. These findings suggest that karyotyping should be part of the investigation for Brazilian couples with RPL, as identifying the genetic etiology may have implications for subsequent pregnancies.

Clinical characteristics of 11 patients with chronic lymphocytic leukemia with t (14;19) (q32;q13) / 中华血液学杂志

Objective: To analyze the clinicopathological characteristics of 11 cases of chronic lymphocytic leukemia (CLL) with t (14;19) (q32;q13) . Methods: The case data of 11 patients with CLL with t (14;19) (q32;q13) in the chromosome karyotype analysis results of the Blood Diseases Hospital, Chinese Academy of Medical Sciences from January 1, 2018, to July 30, 2022, were retrospectively analyzed. Results: In all 11 patients, t (14;19) (q32;q13) involved IGH::BCL3 gene rearrangement, and most of them were accompanied by +12 or complex karyotype. An immunophenotypic score of 4-5 was found in 7 patients and 3 in 4 cases. We demonstrated that CLLs with t (14;19) (q32;q13) had a mutational pattern with recurrent mutations in NOTCH1 (3/7), FBXW7 (3/7), and KMT2D (2/7). The very-high-risk, high-risk, intermediate-risk, and low-risk groups consisted of 1, 1, 6, and 3 cases, respectively. Two patients died, 8 survived, and 2 were lost in follow-up. Four patients had disease progression or relapse during treatment. The median time to the first therapy was 1 month. Conclusion: t (14;19) (q32;q13), involving IGH::BCL3 gene rearrangement, is a rare recurrent cytogenetic abnormality in CLL, which is associated with a poor prognosis.

Clinicopathological features of gastric carcinomas with NTRK-rearrangement/amplification: report of four cases / 中华病理学杂志

Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of gastric carcinoma with NTRK-rearrangement/amplification. Methods: The clinicopathological data of gastric carcinoma cases with NTRK-rearrangement/amplification diagnosed from January 2011 to September 2020 at the Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, China, were collected. The clinicopathological, immunophenotypic and molecular pathological features were analyzed. The relevant literature was reviewed. Results: There were 4 cases of gastric carcinoma with NTRK-rearrangement/amplification. All 4 patients were male, aged 57-67 years (average, 63 years). Tumor sizes ranged from 3.5 to 5.2 cm (average, 4.8 cm). All tumors were in the antrum. All 4 patients underwent radical gastrectomy and were followed up after the surgery. Morphologically, all tumors showed histological features with enteroblastic-differentiated gastric carcinoma. Tumor cells showed predominantly tubular/papillary architecture, with conspicuous vesicular nuclei and pale staining or transparent cytoplasm. Immunohistochemistry showed pan-TRK expression in all cases, with various degrees of positivity in the cytoplasm. All cases were subject to NTRK1/2/3 detection using fluorescence in situ hybridization. There were NTRK translocations in 2 cases and NTRK amplifications in 2 cases. These cases were further verified by RNAseq next generation sequencing which confirmed that NTRK1 gene translocation (TPM3-NTRK1) and NTRK2 gene translocation (NTRK2-SMCHD1) occurred in two cases, respectively. Conclusions: NTRK mutation occurs less frequently in gastric cancer. In this study, the cases mainly occur in the antrum. The morphology has the characteristics of enteroblastic differentiation. The tumors have unique histological, immunophenotypic and molecular characteristics, which require much attention from pathologists to effectively guide clinicians to choose the best treatment.

Analysis of a fetus with unbalanced translocation derived from a balanced t(6;14) maternal translocation / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a fetus with a high risk by maternal serum screening during the second trimester.@*METHODS@#Genetic counseling was provided to the pregnant woman on March 22, 2020 at Henan Provincial People's Hospital. G-banded chromosomal karyotyping and array comparative genomic hybridization (aCGH) were carried out on the amniotic fluid sample and peripheral blood samples from the couple.@*RESULTS@#The fetus and the pregnant woman were respectively found to have a 46,XX,der(6)t(6;14)(q27;q31.2) and 46,XX,t(6;14)(q27;q31.2) karyotype, whilst the husband was found to have a normal karyotype. aCGH analysis has identified a 6.64 Mb deletion at 6q26q27 and a 19.98 Mb duplication at 14q31.3q32.33 in the fetus, both of which were predicted to be pathogenic copy number variations. No copy number variation was found in the couple.@*CONCLUSION@#The unbalanced chromosome abnormalities in the fetus have probably derived from the balanced translocation carried by the pregnant woman. aCGH can help to determine the types of fetal chromosome abnormalities and site of chromosomal breakage, which may facilitate the prediction of fetal outcome and choice for subsequent pregnancies.

Genetic analysis of a case of B-acute lymphoblastic leukaemia with double Philadelphia chromosomes and double derivative chromosome 9s / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a rare case of acute B-lymphocytic leukemia (B-ALL) with double Philadelphia chromosomes (Ph) and double derivative chromosome 9s [der(9)].@*METHODS@#A patient with double Ph and double der(9) B-ALL who presented at Shanghai Zhaxin Intergrated Traditional Chinese and Western Medicine Hospital in June 2020 was selected as the subject. Bone marrow morphology, flow cytometry, G-banding karyotyping, fluorescence in situ hybridization (FISH), genetic testing and chromosomal microarray analysis (CMA) were used to analyze bone marrow samples from the patient at various stages.@*RESULTS@#At initial diagnosis, the patient's bone marrow morphology and flow immunotyping have both supported the diagnosis of B-ALL. G-banded karyotyping of the patient indicated double Ph, in addition with hyperdiploid chromosomes involving translocations between chromosomes 9 and 22. BCR-ABL1 fusion gene was positive. Genetic testing at the time of recurrence revealed presence of a heterozyous c.944C>T variant in the kinase region of the ABL1 gene. FISH showed a signal for ABL1-BCR fusion on both chromosome 9s. CMA showed that the mosaicism homozygosity ratio of chromosome 9 was about 40%, and the mosaicism duplication ratio of chromosome 22 was about 43%.@*CONCLUSION@#Since both der(9) homologs were seen in 40% of cells, the possible mechanism for the double der(9) in this patient may be similar to that of double Ph, which might have resulted from non-disjunction during mitosis in the Ph chromosome-positive cell clone.

Tools for large-scale genetic manipulation of yeast genome / 生物工程学报

Large-scale genetic manipulation of the genome refers to the genetic modification of large fragments of DNA using knockout, integration and translocation. Compared to small-scale gene editing, large-scale genetic manipulation of the genome allows for the simultaneous modification of more genetic information, which is important for understanding the complex mechanisms such as multigene interactions. At the same time, large-scale genetic manipulation of the genome allows for larger-scale design and reconstruction of the genome, and even the creation of entirely new genomes, with great potential in reconstructing complex functions. Yeast is an important eukaryotic model organism that is widely used because of its safety and easiness of manipulation. This paper systematically summarizes the toolkit for large-scale genetic manipulation of the yeast genome, including recombinase-mediated large-scale manipulation, nuclease-mediated large-scale manipulation, de novo synthesis of large DNA fragments and other large-scale manipulation tools, and introduces their basic working principles and typical application cases. Finally, the challenges and developments in large-scale genetic manipulation are presented.

Genetic analysis of a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11) / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal genetic testing for a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11).@*METHODS@#A pregnant woman who had visited the Birth Health Clinic of Lianyungang Maternal and Child Health Care Hospital on May 22, 2021 was selected as the study subject. Clinical data of the woman was collected. Peripheral blood samples of the woman and her husband and umbilical cord blood of the fetus were collected and subjected to conventional G-banded chromosomal karyotyping analysis. Fetal DNA was also extracted from amniotic fluid sample and subjected to chromosomal microarray analysis (CMA).@*RESULTS@#For the pregnant women, ultrasonography at 25th gestational week had revealed permanent left superior vena cava and mild mitral and tricuspid regurgitation. G-banded karyotyping analysis showed that the pter-q11 segment of the fetal Y chromosome was connected to the Xq26 of the X chromosome, suggesting a Xq-Yq reciprocal translocation. No obvious chromosomal abnormality was found in the pregnant woman and her husband. The CMA results showed that there was approximately 21 Mb loss of heterozygosity at the end of the long arm of the fetal X chromosome [arr [hg19] Xq26.3q28(133912218_154941869)×1], and 42 Mb duplication at the end of the long arm of the Y chromosome [arr [hg19] Yq11.221qter(17405918_59032809)×1]. Combined with the search results of DGV, OMIM, DECIPHER, ClinGen and PubMed databases, and based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the deletion of arr[hg19] Xq26.3q28(133912218_154941869)×1 region was rated as pathogenic, and the duplication of arr[hg19] Yq11.221qter(17405918_59032809)×1 region was rated as variant of uncertain significance.@*CONCLUSION@#The Xq-Yq reciprocal translocation probably underlay the ultrasonographic anomalies in this fetus, and may lead to premature ovarian insufficiency and developmental delay after birth. Combined G-banded karyotyping analysis and CMA can determine the type and origin of fetal chromosomal structural abnormalities as well as distinguish balanced and unbalanced translocations, which has important reference value for the ongoing pregnancy.

Clinical significance of PDGFRβ gene testing in hematological tumors / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical and laboratory characteristics of hematological tumors with different types of abnormalities in platelet derived growth factor β (PDGFRβ) gene.@*METHODS@#A retrospective analysis was carried out on 141 patients with abnormal long arm of chromosome 5 (5q) and comprehensive medical history data from Changhai Hospital Affiliated to Naval Medical University from 2009 to 2020, and their clinical data were collected. R-banding technique was used for chromosomal karyotyping analysis for the patient's bone marrow, and fluorescence in situ hybridization (FISH) was used to detect the PDGFRβ gene. The results of detection were divided into the amplification group, deletion group, and translocation group based on FISH signals. The three sets of data column crosstabs were statistically analyzed, and if the sample size was n >= 40 and the expected frequency T for each cell was >= 5, a Pearson test was used to compare the three groups of data. If N < 40 and any of the expected frequency T for each cell was < 5, a Fisher's exact test is used. Should there be a difference in the comparison results between the three sets of data, a Bonferroni method was further used to compare the data.@*RESULTS@#In total 98 patients were detected to have PDGFRβ gene abnormalities with the PDGFRβ probe, which yielded a detection rate of 69.50% (98/141). Among these, 38 cases (38.78%) had PDGFRβ gene amplifications, 57 cases (58.16%) had deletions, and 3 (3.06%) had translocations. Among the 98 cases, 93 were found to have complex karyotypes, including 37 cases from the amplification group (97.37%, 37/38), 55 cases from the deletion group (96.49%, 55/57), and 1 case from the translocation group (33.33%, 1/3). Analysis of three sets of clinical data showed no significant gender preponderance in the groups (P > 0.05). The PDGFRβ deletion group was mainly associated with myeloid tumors, such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) (P < 0.001). The PDGFRβ amplification group was more common in lymphoid tumors, such as multiple myeloma (MM) (P < 0.001). The PDGFRβ translocation group was also more common in myelodysplastic/myeloproliferative tumors (MDS/MPN).@*CONCLUSION@#Tumors with PDGFRβ gene rearrangement may exhibit excessive proliferation of myeloproliferative tumors (MPN) and pathological hematopoietic changes in the MDS, and have typical clinical and hematological characteristics. As a relatively rare type of hematological tumor, in addition to previously described myeloid tumors such as MPN or MDS/MPN, it may also cover lymphoid/plasma cell tumors such as multiple myeloma and non-Hodgkin's lymphoma.

Genetic analysis of two cases with MYC "negative" Burkitt lymphoma / 中华医学遗传学杂志

OBJECTIVE@#To carry out combined genetic analysis on two patients suspected for Burkitt lymphoma to facilitate their diagnosis and treatment.@*METHODS@#G banded karyotyping and interphase and metaphase fluorescence in situ hybridization (FISH) were used to detect the specific sites of chromosomes by using separate and fusion probes.@*RESULTS@#The separate probe showed no presence of MYC gene abnormality, while fusion probe confirmed the IGH::MYC translocation in the samples. Combined with the clinical features and pathological characteristics, the two patients were finally diagnosed with Burkitt lymphoma, which was confirmed by targeted capture next generation sequencing.@*CONCLUSION@#The separate probe for the MYC gene has some shortcomings and should be used together with dual fusion probe to improve the accuracy of diagnosis.

Chromosomal microarray analysis of 17 patients with unbalanced reciprocal translocations / 中华医学遗传学杂志

OBJECTIVE@#To retrospectively analyze the results of chromosomal microarray analysis (CMA) and parental origins of unbalanced translocations among 17 patients, so as to provide reference for their genetic counseling.@*METHODS@#The results of CMA for 7 001 samples tested in Chengdu Women and Children's Central Hospital from January 2019 to January 2022 were retrospectively reviewed. Unbalanced reciprocal translocation was defined as two non-homologous chromosomes with lost and gained segments respectively or both with gained segments, and their parental origins were identified by parental chromosomal karyotyping and/or fluorescence in situ hybridization (FISH).@*RESULTS@#In total 17 unbalanced translocations were identified. In three cases, two non-homologous chromosomes both had gained segments, which constituted a derivative chromosome, with the total number of chromosomes being 47. In the remaining 14 cases, there was a terminal deletion on one chromosome and a terminal duplication on the other, 10 of which were confirmed by karyotyping, with the total number of chromosomes being 46. In the derivative chromosome, the lost segment was replaced by a gained segment from another chromosome. Among 15 cases undergoing parental origin analysis, 12 had paternal or maternal chromosomal abnormalities, including 11 balanced translocations and 1 unbalanced translocation. The unbalanced gametes therefore may form through meiosis. In 3 cases, the parental chromosomes were normal, indicating a de novo origin.@*CONCLUSION@#Discovery of terminal duplication and deletion or gained segments on two non-homologous chromosomes by CMA is suggestive of parental balanced translocation, which can facilitate genetic counseling and assessment the recurrence risk for subsequent pregnancies.

Analysis of the characteristics of primary acute myeloid leukemia with 11q23/KMT2A rearrangements in ninety patients / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical and prognostic characteristics of primary acute myeloid leukemia (AML) with 11q23/KMT2A rearrangements.@*METHODS@#Clinical data of 90 patients with primary AML and 11q23/KMT2A rearrangements were analyzed retrospectively.@*RESULTS@#By karyotyping analysis, 80 of the 90 patients had translocations involving 11q23/KMT2A, with t(9;11)(p22;q23), t(6;11)(q27;q23), t(10;11)(p12;q23) and t(11;19)(q23;p13) being the most common ones, while 10 cases were found to have non-translocation abnormalities. The overall complete remission (CR) rate was 75.6%, and patients with t(6;11) had lower CR rate compared with non-t(6;11) patients (47.1% vs. 82.2%, P = 0.005). After a median follow-up of 24.5 months, the patients receiving allo-hematopoietic stem cell transplantation (allo-HSCT) had significantly higher 3-year overall survival (OS) (80.3% vs. 16.6%, P < 0.001) and 3-year event-free survival (EFS) (73.5% vs. 16.3%, P < 0.001) compared with non-transplant patients. Patients with t(6;11) had the lowest 3-year OS (11.8% vs. 56.0%, P < 0.001) and 3-year EFS (5.9% vs. 53.8%, P < 0.001) compared with other type of abnormalities. No significant difference was noted in the survival between patients with t(9;11) and non-t(9;11) regardless whether they had received HSCT.@*CONCLUSION@#The clinical characteristics of primary AML with 11q23/KMT2A rearrangements are heterogeneous. Patients did not receive HSCT had poorer survival, particularly with the presence of t(6;11). Allo-HSCT could significantly improve the survival of such patients.

GID complex regulates the differentiation of neural stem cells by destabilizing TET2 / 医学前沿

Brain development requires a delicate balance between self-renewal and differentiation in neural stem cells (NSC), which rely on the precise regulation of gene expression. Ten-eleven translocation 2 (TET2) modulates gene expression by the hydroxymethylation of 5-methylcytosine in DNA as an important epigenetic factor and participates in the neuronal differentiation. Yet, the regulation of TET2 in the process of neuronal differentiation remains unknown. Here, the protein level of TET2 was reduced by the ubiquitin-proteasome pathway during NSC differentiation, in contrast to mRNA level. We identified that TET2 physically interacts with the core subunits of the glucose-induced degradation-deficient (GID) ubiquitin ligase complex, an evolutionarily conserved ubiquitin ligase complex and is ubiquitinated by itself. The protein levels of GID complex subunits increased reciprocally with TET2 level upon NSC differentiation. The silencing of the core subunits of the GID complex, including WDR26 and ARMC8, attenuated the ubiquitination and degradation of TET2, increased the global 5-hydroxymethylcytosine levels, and promoted the differentiation of the NSC. TET2 level increased in the brain of the Wdr26+/- mice. Our results illustrated that the GID complex negatively regulates TET2 protein stability, further modulates NSC differentiation, and represents a novel regulatory mechanism involved in brain development.

Investigation of the genetic etiology in male infertility with apparently balanced chromosomal structural rearrangements by genome sequencing / 亚洲男科学杂志(英文版)

Apparently balanced chromosomal structural rearrangements are known to cause male infertility and account for approximately 1% of azoospermia or severe oligospermia. However, the underlying mechanisms of pathogenesis and etiologies are still largely unknown. Herein, we investigated apparently balanced interchromosomal structural rearrangements in six cases with azoospermia/severe oligospermia to comprehensively identify and delineate cryptic structural rearrangements and the related copy number variants. In addition, high read-depth genome sequencing (GS) (30-fold) was performed to investigate point mutations causative of male infertility. Mate-pair GS (4-fold) revealed additional structural rearrangements and/or copy number changes in 5 of 6 cases and detected a total of 48 rearrangements. Overall, the breakpoints caused truncations of 30 RefSeq genes, five of which were associated with spermatogenesis. Furthermore, the breakpoints disrupted 43 topological-associated domains. Direct disruptions or potential dysregulations of genes, which play potential roles in male germ cell development, apoptosis, and spermatogenesis, were found in all cases (n = 6). In addition, high read-depth GS detected dual molecular findings in case MI6, involving a complex rearrangement and two point mutations in the gene DNAH1. Overall, our study provided the molecular characteristics of apparently balanced interchromosomal structural rearrangements in patients with male infertility. We demonstrated the complexity of chromosomal structural rearrangements, potential gene disruptions/dysregulation and single-gene mutations could be the contributing mechanisms underlie male infertility.

Genetic variation of YWHAE gene-"Switch" of disease control / 中南大学学报(医学版)

YWHAE gene is located on chromosome 17p13.3, and its product 14-3-3epsilon protein belongs to 14-3-3 protein family. As a molecular scaffold, YWHAE participates in biological processes such as cell adhesion, cell cycle regulation, signal transduction and malignant transformation, and is closely related to many diseases. Overexpression of YWHAE in breast cancer can increase the ability of proliferation, migration and invasion of breast cancer cells. In gastric cancer, YWHAE acts as a negative regulator of MYC and CDC25B, which reduces their expression and inhibits the proliferation, migration, and invasion of gastric cancer cells, and enhances YWHAE-mediated transactivation of NF-κB through CagA. In colorectal cancer, YWHAE lncRNA, as a sponge molecule of miR-323a-3p and miR-532-5p, can compete for endogenous RNA through direct interaction with miR-323a-3p and miR-532-5p, thus up-regulating K-RAS/ERK/1/2 and PI3K-AKT signaling pathways and promoting the cell cycle progression of the colorectal cancer. YWHAE not only mediates tumorigenesis as a competitive endogenous RNA, but also affects gene expression through chromosome variation. For example, the FAM22B-YWHAE fusion gene caused by t(10; 17) (q22; p13) may be associated with the development of endometrial stromal sarcoma. At the same time, the fusion transcript of YWHAE and NUTM2B/E may also lead to the occurrence of endometrial stromal sarcoma. To understand the relationship between YWHAE, NUTM2A, and NUTM2B gene rearrangement/fusion and malignant tumor, YWHAE-FAM22 fusion gene/translocation and tumor, YWHAE gene polymorphism and mental illness, as well as the relationship between 17p13.3 region change and disease occurrence. It provides new idea and basis for understanding the effect of YWHAE gene molecular mechanism and genetic variation on the disease progression, and for the targeted for the diseases.

Efficacy and initial clinical evaluation of optical genome mapping in the diagnosis of structural variations / 中华预防医学杂志

To investigate the efficacy and value of optical genome mapping (OGM) in detecting chromosomal structural variations. In a clinical study about high-precision analysis of genomic structural variation for complex genetic diseases, a retrospective study was performed on the cases with karyotyping at the department of Obstetrics and Gynecology, and Endocrinology of Peking Union Medical College Hospital from January to December 2021. Ten cases with abnormal karyotype was detected by OGM. Partial cases were verified by fluorescence in situ hybridization (FISH), SNP array or CNV-seq. Results of ten cases, nine were detected with abnormality by OGM, including unbalanced chromosomal rearrangements (n=3), translocation (n=5) and paracentric inversion (n=1), and the results were in concordance with other standard assays. However, one case with breakpoint and reconnected at centromere has not been detected. In conclusion, ten samples were comprehensively analyzed by karyotyping, FISH, SNP array or CNV-seq, and OGM, and results demonstrated that optical genome mapping as a new technology can not only detect unbalanced rearrangements such as copy number variants as well as balanced translocations and inversions, but more importantly, it can refine breakpoints and orientation of duplicated segments or insertions. So it can contribute to the diagnosis of genetic diseases and prevent birth defect. However, the current technology is not yet capable of detecting breakpoints of balanced structural variations lying within unmapped regions.

Application of CNV-seq and chromosomal karyotyping in the prenatal diagnosis for carriers of balanced translocations / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of copy number variation sequencing (CNV-seq) and karyotyping in the prenatal diagnosis for carriers of balanced translocations.@*METHODS@#Clinical records of 135 amniocentesis samples of balanced translocation carriers undergoing simultaneous CNV-seq and karyotyping were analyzed. Chromosomal aberrations were defined as those can definitely lead to birth defects definitely, which included chromosomal numerical abnormality, large deletion/duplication and pathogenic copy number variations (pCNVs).@*RESULTS@#The detection rates for karyotyping and CNV-seq were 4.44% (6/135) and 5.93% (8/135) respectively, and the latter had a detection rate of 1.48(2/135) higher than the former. A total of 68 fetal chromosomal translocations were detected by karyotying analysis.@*CONCLUSION@#For couples carrying a balanced translocation, simultaneous CNV-seq and karyotyping is conducive to the detection of fetal chromosomal abnormalities and genetic counseling.

Clinical genetic analysis of an infant with 1q21.3-qter duplication and Xpter-p11 deletion caused by maternal balanced chromosomal translocation / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical phenotype and genetic diagnosis of an infant featuring multiple hair and hyperbilirubinemia.@*METHODS@#Conventional G-banding analysis, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) for the patient were conducted, G-banding analyses of peripheral blood for the infant's parents were also performed.@*RESULTS@#We investigated an infant who carries a unbalanced, maternally inherited karyotype 46, X, der (X) t (X;1) (p11.22; q21.3) in which CMA and FISH analyses disclosed a 1q21.3q44 duplication of 93.03 Mb and Xp22.33p11.22 deletion of 54.53 Mb.@*CONCLUSION@#The phenotypes of this infant can probably be attributed to the 1q21.3q44 duplication and Xp22.33p11.22 deletion, which were maternally inherited.

Identificação de regiões candidatas a mapeamento fenotípico anormal a partir de rearranjos cromossômicos estruturais considerados balanceados / Identification of candidate regions for abnormal phenotypic mapping from structural chromosome rearrangements considered to be balanced

A maioria dos casos de portadores de translocações balanceadas são clinicamente normais, porém, cerca de 7% delas estão associadas a alterações fenotípicas, que incluem malformações congênitas e/ou retardo mental. Investigações detalhadas das regiões dos sítios de quebra desses rearranjos estruturais aparentemente balanceados, têm sido utilizadas como estratégia na busca de novos genes candidatos a esses fenótipos clínicos. Este projeto visa caracterizar casos de anomalias cromossômicas estruturais, especialmente os casos de translocações aparentemente balanceadas, em nível da citogenética clássica, pelas técnicas de bandeamento de cromossomos metafásicos e citogenética molecular, pela metodologia de Hibridização in Situ por Fluorescência (FISH) e técnicas de biologia molecular, como: Hibridização Genômica Comparativa baseada em microarranjos (a-CGH) e Sequenciamento de "mate-pair" delimitando regiões de busca para genes candidatos. E portanto, contribuir para o entendimento dos mecanismos que podem levar à um desfecho de alteração fenotípica em pacientes com translocações aparentemente balanceadas. Foram incluídos no projeto 5 casos de pacientes do Centro de Genética Médica que eram portadores de translocações aparentemente balanceadas de novo associados a fenótipo alterados. Caso 1 apresentou uma translocação recíproca entre o braço longo cromossomo 1 e braço longo do cromossomo 8 [46, XY, t(1;8)(p31;q13)], as análises realizadas sugeriram o gene PLPP3 como o provável candidato para correlação com o fenótipo e uma quebra intragência no gene SLCOA5, que está associado a síndrome Mesomelia-Sinostose. O caso 2 possuí uma translocação recíproca entre o braço longo do cromossomo 1 e braço longo do cromossomo 18 [46, XX, t(1;18)(q43;q11.1)], apresentando quadro clínico compatível com a síndrome de Mayer-Rokitansky-Kuster-Hauser (MRKH), o gene GREB1L, localizado na região de quebra 18q11, foi considerado como o principal candidato de interesse a mapeamento fenotípico associado a esta síndrome. O caso 3 é portador de uma translocação envolvendo o braço curto do cromossomo X e o braço longo de um cromossomo autossômico [46, XX, t(X;18)( p21.2;q22.3)], o sequenciamento de mate-pair demosntrou uma quebra gênica em DMD, sendo crucial para o diagnóstico clínico da paciente. O caso 4 apresenta uma translocação entre o braço longo do cromossomo 18 e braço longo do cromossomo 21 [46, XY t (18;21)(q23;q22.1)], foi observado uma microdeleção na região 18q23 por array-CGH que incluía o gene TSHZ1, deleções ou mutações neste gene estão associadas a fenótipos que se relacionam com o quadro clínico do paciente. O caso 5 é portador de uma translocação entre o braço curto do cromossomo 12 e cromossomo 22 [45, XX, -22(p13;q11)] com suspeita clínica de Síndrome de Edwards, foram identificadas duas perdas patogênicas na paciente, uma no cromossomo 13 e outra no cromossomo 22. Devido a presença de alterações adicionais a translocação não foi possível sugerir um gene ou região candidata a relação genótipo-fenótipo da paciente.

Most cases of patients with balanced translocations are clinically normal, and about 7% of them are associated with phenotypic changes, which include congenital malformations and/or mental retardation. Related investigations of the break site regions of these apparently balanced rearrangements have been used as a strategy in the search for new candidate genes for these abnormal clinical phenotypes. This project aims to characterize cases of chromosomal anomalies present, especially cases of apparently balanced translocations, at the level of classical cytogenetics, by metaphase chromosome banding techniques, molecular cytogenetics, by Fluorescence in Situ Hybridization (FISH) methodology and sequencing techniques of Deoxyribonucleic Acid (DNA), Comparative Genomic Hybridization based on microarrays (a-CGH) and "mate-pair" sequencing delimiting search regions for genes and candidates for the understanding of individuals that can lead to an outcome of phenotypic change in patients with apparently balanced translocations. The project included 5 cases of patients from the Medical Genetics Center who were carriers of apparently de novo balanced translocations associated with altered phenotype. Case 1 showed a reciprocal translocation between the long arm of chromosome 1 and the long arm of chromosome 8 [46, XY, t(1;8)(p31;q13)], the analyses performed suggested the PLPP3 gene as the likely candidate for correlation with the phenotype and an intragenic break in the SLCOA5 gene, which is associated with Mesomelia-Synostosis syndrome. Case 2 carries a reciprocal translocation between the long arm of chromosome 1 and the long arm of chromosome 18 [46, XX, t(1;18)(q43;q11.1)], presenting a clinical picture compatible with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome, the GREB1L gene, located in the 18q11 break region, was considered as the main candidate of interest for phenotype mapping associated with this syndrome. Case 3 has a translocation involving the short arm of the X chromosome and the long arm of an autosomal chromosome [46, XX, t(X;18)( p21.2;q22.3)], mate-pair sequencing demonstrated a gene break in DMD, being crucial for the clinical diagnosis of the patient. Case 4 has a translocation between the long arm of chromosome 18 and long arm of chromosome 21 [46, XY t (18;21)(q23;q22.1)], a microdeletion was observed in the 18q23 region by array-CGH that included the TSHZ1 gene, deletions or mutations in this gene are associated with phenotypes that relate to the patient's clinical picture. Case 5 carries a translocation between the short arm of chromosome 12 and chromosome 22 [45, XX, -22(p13;q11)] with clinical suspicion of Edwards Syndrome, two pathogenic losses were identified in the patient, one on chromosome 13 and one on chromosome 22. Due to the presence of additional alterations to the translocation it was not possible to suggest a candidate gene or region for the patient's genotype-phenotype correlations.

Carcinoma papilífero de tireoide pediátrico associado à fusão gênica RET-PTC6: relato de caso / Pediatric papillary thyroid carcinoma associated with RET-PTC6 gene fusion: a case report

Introdução: o carcinoma papilífero de tireoide é a neoplasia maligna que mais acomete o sistema endócrino, correspondendo a cerca de 90% dos casos. Diante de sua frequência, nas últimas décadas, foi registrado um aumento do número de casos na população pediátrica e, devido a isso, o número de crianças e adolescentes submetidos à tireoidectomia se tornou cada vez maior. Enquanto as alterações gênicas mais encontradas em adultos com carcinoma papilífero concentram-se em mutações pontuais, na população pediátrica as fusões gênicas são mais frequentes, com destaque para os rearranjos RET/PTC. Objetivo: relatar aspectos clínico-patológicos do carcinoma papilífero de tireoide, associado à fusão do gene RET, em criança submetida à tireoidectomia e radioiodoterapia adjuvante. Em seguida, discute-se a importância do diagnóstico molecular na escolha de terapias relevantes no tratamento do CPT. Caso Clínico: trata-se de uma paciente do sexo feminino, 11 anos de idade, submetida a tireoidectomia total e esvaziamento cervical após diagnóstico do referido carcinoma. O estudo anatomopatológico revelou um carcinoma metastático em linfonodos regionais. Utilizou-se uma amostra de tecido em bloco de parafina para a realização de um sequenciamento de nova geração, que apontou a existência da fusão gênica TRIM24-RET. Conclusão: os dados deste relato de caso evidenciam que a mutação RET/PTC6 está muito associada à população pediátrica e que testes moleculares, como o NGS, são de extremo valor na identificação dessas alterações gênicas e, consequentemente, na terapia a ser adotada para cada paciente.

Introduction: thyroid papillary carcinoma is the malignant neoplasm that most affects the endocrine system, corresponding to about 90% of cases. Given its frequency, in recent decades, there has been an increase in the number of cases in the pediatric population and, as a result, the number of children and adolescents undergoing thyroidectomy has become increasingly larger. While the most common gene alterations found in adults with papillary carcinoma are concentrated in point mutations, in the pediatric population gene fusions are more frequent, with emphasis on the RET/PTC rearrangements. Objective: to report clinical and pathological aspects of papillary thyroid carcinoma associated with RET gene fusion in a child undergoing thyroidectomy and adjuvant radioiodine therapy. Then, the importance of molecular diagnosis in choosing relevant therapies in the treatment of PTC is discussed. Clinical Case: this is an 11-year-old female patient who underwent total thyroidectomy and neck dissection after diagnosis of the aforementioned carcinoma. The anatomopathological study revealed a metastatic carcinoma in regional lymph nodes. A tissue sample in paraffin block was used to perform a new generation sequencing, which showed the existence of the TRIM24-RET gene fusion. Conclusion: the data in this case report show that the RET/PTC6 mutation is closely associated with the pediatric population and that molecular tests, such as the NGS, are extremely valuable in identifying these genetic alterations and, consequently, in the therapy to be adopted for each patient.