Clinical application of the HM-1000 image processing for HER2 fluorescence in situ hybridization signal quantification in breast cancer.

BACKGROUND: Accurate quantification of human epidermal growth factor receptor 2 (HER2) gene amplification is important for predicting treatment response and prognosis in patients with breast cancer. Fluorescence in situ hybridization (FISH) is the gold standard for the diagnosis of HER2 status, particularly in cases with equivocal status on immunohistochemistry (IHC) staining, but has some limitations of non-classical amplifications and such cases are diagnosed basing on additional IHC and FISH. This study investigated the clinical utility of a novel super-resolution fluorescence microscopy technique for the better FISH signal visualization and HER2 FISH classification. METHODS: Fourteen breast cancer tissue samples were retrospectively collected between September 2018 and February 2022, and FISH HER2 signal quantification was evaluated by determining the HER2/chromosome 17 centromere (CEP17) ratio and the number of HER2 signals per nucleus in super- versus conventional-resolution images. RESULTS: Super-resolution images maintained the same overall HER2 diagnosis from routine, but HER2 FISH amplification changed negative to monosomy in two cases. Two Letrozole non-response relapses coincided to monosomy samples. The median number of HER2 signals per nucleus was 7.5 in super-resolution images and 4.0 in conventional-resolution images in HER2-positive samples and 2.8 and 2.1 signals per nucleus, respectively, in HER2-negative samples. CONCLUSIONS: Super-resolution images improved signal visualization, including a significant difference in the number of countable HER2 and CEP17 signals in a single nucleus compared with conventional-resolution images. Increased accuracy of signal quantification by super-resolution microscopy may provide clinicians with more detailed information regarding HER2 FISH status that allows to better FISH classification such as HER2-low samples.

Natural killer cells drive 4-1BBL positive uveal melanoma towards EMT and metastatic disease.

BACKGROUND: Inflammation in the eye is often associated with aggravated ocular diseases such as uveal melanoma (UM). Poor prognosis of UM is generally associated with high potential of metastatic liver dissemination. A strong driver of metastatic dissemination is the activation of the epithelial-mesenchymal transition (EMT) regulating transcription factor ZEB1, and high expression of ZEB1 is associated with aggressiveness of UM. While ZEB1 expression can be also associated with immune tolerance, the underlying drivers of ZEB1 activation remain unclear. METHODS: Transcriptomic, in vitro, ex vivo, and in vivo analyses were used to investigate the impact on clinical prognosis of immune infiltration in the ocular tumor microenvironment. A metastatic liver dissemination model of was developed to address the role of natural killer (NK) cells in driving the migration of UM. RESULTS: In a pan-cancer TCGA analysis, natural killer (NK) cells were associated with worse overall survival in uveal melanoma and more abundant in high-risk monosomy 3 tumors. Furthermore, uveal melanoma expressed high levels of the tumor necrosis factor superfamily member 4-1BB ligand, particularly in tumors with monosomy 3 and BAP1 mutations. Tumors expressing 4-1BB ligand induced CD73 expression on NK cells accompanied with the ability to promote tumor dissemination. Through ligation of 4-1BB, NK cells induced the expression of the ZEB1 transcription factor, leading to the formation of liver metastasis of uveal melanoma. CONCLUSIONS: Taken together, the present study demonstrates a role of NK cells in the aggravation of uveal melanoma towards metastatic disease.

Detection of Copy-Number Variation in Circulating Cell-Free DNA in Patients With Uveal Melanoma.

PURPOSE: Somatic chromosomal alterations, particularly monosomy 3 and 8q gains, have been associated with metastatic risk in uveal melanoma (UM). Whole genome-scale evaluation of detectable alterations in cell-free DNA (cfDNA) in UM could provide valuable prognostic information. Our pilot study evaluates the correlation between genomic information using ultra-low-pass whole-genome sequencing (ULP-WGS) of cfDNA in UM and associated clinical outcomes. MATERIALS AND METHODS: ULP-WGS of cfDNA was performed on 29 plasma samples from 16 patients, 14 metastatic UM (mUM) and two non-metastatic, including pre- and post-treatment mUM samples from 10 patients treated with immunotherapy and one with liver-directed therapy. We estimated tumor fraction (TFx) and detected copy-number alterations (CNAs) using ichorCNA. Presence of 8q amplification was further analyzed using the likelihood ratio test (LRT). RESULTS: Eleven patients with mUM (17 samples) of 14 had detectable circulating tumor DNA (ctDNA). 8q gain was detected in all 17, whereas monosomy 3 was detectable in 10 of 17 samples. TFx generally correlated with disease status, showing an increase at the time of disease progression (PD). 8q gain detection sensitivity appeared greater with the LRT than with ichorCNA at lower TFxs. The only patient with mUM with partial response on treatment had a high pretreatment TFx and undetectable on-treatment ctDNA, correlating with her profound response and durable survival. CONCLUSION: ctDNA can be detected in mUM using ULP-WGS, and the TFx correlates with DS. 8q gain was consistently detectable in mUM, in line with previous studies indicating 8q gains early in primary UM and higher amplification with PD. Our work suggests that detection of CNAs by ULP-WGS, particularly focusing on 8q gain, could be a valuable blood biomarker to monitor PD in UM.

Spontaneous remission and loss of monosomy 7: a window of opportunity for young children with SAMD9L syndrome.

Monosomy 7 is the most common cytogenetic abnormality in pediatric myelodysplastic syndrome (MDS) and associated with a high risk of disease progression. However, in young children, spontaneous loss of monosomy 7 with concomitant hematologic recovery has been described, especially in the presence of germline mutations in SAMD9 and SAMD9L genes. Here, we report on our experience of close surveillance instead of upfront hematopoietic stem cell transplantation (HSCT) in seven patients diagnosed with SAMD9L syndrome and monosomy 7 at a median age of 0.6 years (range, 0.4-2.9). Within 14 months from diagnosis, three children experienced spontaneous hematological remission accompanied by a decrease in monosomy 7 clone size. Subclones with somatic SAMD9L mutations in cis were identified in five patients, three of whom attained hematological remission. Two patients acquired RUNX1 and EZH2 mutations during the observation period, of whom one progressed to myelodysplastic syndrome with excess of blasts (MDS-EB). Four patients underwent allogeneic HSCT at a median time of 26 months (range, 14-40) from diagnosis for MDSEB, necrotizing granulomatous lymphadenitis, persistent monosomy 7, and severe neutropenia. At last follow-up, six patients were alive, while one passed away due to transplant-related causes. These data confirm previous observations that monosomy 7 can be transient in young children with SAMD9L syndrome. However, they also indicate that delaying HSCT poses a substantial risk of severe infection and disease progression. Finally, surveillance of patients with SAMD9L syndrome and monosomy 7 is critical to define the evolving genetic landscape and to determine the appropriate timing of HSCT (clinicaltrials gov. Identifier: NCT00662090).

The Cancer Genome Atlas for uveal melanoma is predictive of patient outcomes.

Uveal melanoma (UM) is the most common primary eye malignancy. Despite excellent local tumor rates, UM is a life-threatening disease with moderate systemic metastatic rates. In the past, certain clinical features were shown to be predictive of patient prognosis, including tumor thickness, tumor diameter, ciliary body involvement, and histopathologic factors. Genetic markers have lately been used to predict patient outcomes. The Cancer Genome Atlas (TCGA) is a worldwide effort developed by the National Cancer Institute and the National Human Genome Research Institute to study numerous mutations in various cancer types. TCGA has explored chromosome copy number alterations in UM, messenger RNA, micro-RNA, and long noncoding RNA expression levels and established four prognostic classes: group A (chromosome 3 and 8 disomy), group B (chromosome 3 disomy and 8q gain), group C (chromosome 3 monosomy and/or 8q gain), and group D (chromosome 3 monosomy and multiple 8q gains). Multiple studies have validated TCGA classification and have reported that it has been highly predictive of UM metastasis and patient survival.

DELE1 haploinsufficiency causes resistance to mitochondrial stress-induced apoptosis in monosomy 5/del(5q) AML.

Monosomy 5 and deletions of the chromosome 5q (-5/del(5q)) are recurrent events in de novo adult acute myeloid leukemia (AML), reaching up to 40% of cases in secondary AML. These chromosome anomalies are associated with TP53 mutations and with very poor prognosis. Using the large Leucegene genomic and transcriptomic dataset composed of 48 -5/del(5q) patient specimens and 367 control AML, we identified DELE1 - located in the common deleted region - as the most consistently downregulated gene in these leukemias. DELE1 encodes a mitochondrial protein recently characterized as the relay of mitochondrial stress to the cytosol through a newly defined OMA1-DELE1-HRI pathway which ultimately leads to the activation of ATF4, the master transcription factor of the integrated stress response. Here, we showed that the partial loss of DELE1 expression observed in -5/del(5q) patients was sufficient to significantly reduce the sensitivity to mitochondrial stress in AML cells. Overall, our results suggest that DELE1 haploinsufficiency could represent a new driver mechanism in -5/del(5q) AML.

Tumor-Associated Retinal Pigmentation in Choroidal Melanoma.

PURPOSE: To report a previously unrecognized choroidal melanoma clinical feature termed tumor-associated retinal pigmentation (TARP) and determine any correlation with tumor biology. DESIGN: Imaging and histologic analysis of a retrospective cohort of patients. PARTICIPANTS: Patients with choroidal melanoma identified as having TARP on funduscopy at the Liverpool Ocular Oncology Centre (LOOC), United Kingdom, from January 2020 through January 2023. METHODS: Clinical and imaging characteristics of patients diagnosed with choroidal melanoma and exhibiting TARP on fundoscopy were documented. Details of these choroidal melanomas were collated and correlated with histopathology and molecular genetic reports. The chromosome 3 status of each tumor was assessed. In enucleated samples, immunostaining was undertaken to determine the nature of the TARP using specific markers (CD68 and MelanA). MAIN OUTCOME MEASURES: Features of TARP on widefield fundus color imaging, fundus autofluorescence (FAF), and OCT were described. Tumor chromosome 3 status and the immunoprofile of the TARP also were collated. RESULTS: Tumor-associated retinal pigmentation had a prevalence rate of 7.47 per 100 cases of choroidal melanoma at the LOOC. Twenty-three eyes with TARP were analyzed, with a mean age of 71.4 years (range, 51-88 years). The median largest basal diameter was 16.10 mm (range, 9.17-21.32 mm), and the mean tumor thickness was 8.04 mm (range, 1.40-13.80 mm). Tumor-associated retinal pigmentation was observed on widefield color fundus imaging, with hypofluorescence on FAF images and represented hyperreflective foci located in intraretinal and subretinal spaces on OCT scans. Seventeen patients (73.9%) underwent enucleation, and 6 patients (26.1%) underwent globe-sparing treatment. Molecular genetic analysis of 20 choroidal melanomas (after enucleation or radiotherapy biopsy) revealed monosomy 3 in 18 tumors (90%). Immunostaining of the TARP in enucleated eyes showed CD68+ melanophages in all 17 patients appearing as scattered cells and aggregates; MelanA findings were negative. CONCLUSIONS: Tumor-associated retinal pigmentation represents tumor-associated macrophages, not melanocytes, within intraretinal and subretinal spaces of larger choroidal melanomas. Radiation treatments need not involve this area in the treatment plan, minimizing radiation-related complications. This novel clinical sign seems to be linked to tumors of high metastatic-risk clinical and genetic characteristics, with a preponderance having monosomy 3 anomalies. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Prognostic impact of complex and/or monosomal karyotypes in post-transplant poor cytogenetic acute myeloid leukaemia: A quantitative approach.

To evaluate the prognostic impact of complex karyotype (CK) and/or monosomal karyotype (MK) in combination with various clinical factors on allogeneic stem cell transplantation (HSCT) outcomes of patients with acute myeloid leukaemia (AML), we analysed the registry database of adult AML patients who underwent allogeneic HSCT between 2000 and 2019 in Japan. Among 16 094 patients, those with poor cytogenetic risk (N = 3345) showed poor overall survival (OS) after HSCT (25.3% at 5 years). Multivariate analyses revealed that CK and/or MK (hazard ratio [HR], 1.31 for CK without MK; 1.27 for MK without CK; and 1.73 for both), age at HSCT ≥50 years (HR, 1.58), male sex (HR, 1.40), performance status ≥2 (HR, 1.89), HCT-CI score ≥3 (HR, 1.23), non-remission status at HSCT (HR, 2.49), and time from diagnosis to HSCT ≥3 months (HR, 1.24) independently reduced post-HSCT OS among patients with poor cytogenetic risk AML. A risk scoring system based on the multivariate analysis successfully stratified patients into five distinct groups for OS. This study confirms the negative effects of CK and MK on post-HSCT outcomes, and offers a powerful risk scoring system for predicting prognoses after HSCT among AML patients with unfavourable cytogenetics.

Factors predicting survival following alloSCT in patients with therapy-related AML and MDS: a multicenter study.

Therapy-related myeloid neoplasms (t-MN) are aggressive myeloid neoplasms. Factors predicting post-allogeneic stem cell transplant (alloSCT) survival are not well-known. We studied the prognostic utility of factors at: t-MN diagnosis, pre-alloSCT, and post-alloSCT. Primary endpoints were 3-year overall survival (OS), relapse incidence (RI), and non-relapse mortality (NRM). Post-alloSCT OS did not differ between t-MDS and t-AML (20.1 vs. 19.6 months, P = 1), though t-MDS had a significantly higher 3-year RI compared to t-AML (45.1% vs. 26.9%, P = 0.03). In t-MDS, the presence of monosomy 5 (HR 3.63, P = 0.006) or monosomy 17 (HR 11.81, P = 0.01) pre-alloSCT were associated with higher RI. Complex karyotype was the only factor adversely influencing survival at all the timepoints. The inclusion of genetic information yielded 2 risk-categories: high-risk defined by the presence of pathogenic variants (PV) in (TP53/BCOR/IDH1/GATA2/BCORL1) and standard-risk (remainder of the patients) with 3-year post-alloSCT OS of 0% and 64.6%, respectively (P = 0.001). We concluded that while alloSCT was curative in a subset of t-MN patients, outcomes remained poor, specifically in the high-risk category. t-MDS patients, especially those with persistent disease pre-alloSCT were at increased risk of relapse. Disease-related factors at t-MN diagnosis were the most prognostic of post-alloSCT survival; utility of factors available later in the course, was incremental.

Clinical, Histopathologic and Genetic Features of Rhabdoid Meningiomas.

Rhabdoid meningiomas (RM) shows heterogeneous histological findings, and a wide variety of chromosomal copy number alterations (CNA) are associated with an unpredictable course of the disease. In this study, we analyzed a series of 305 RM samples from patients previously reported in the literature and 33 samples from 23 patients studied in our laboratory. Monosomy 22-involving the minimal but most common recurrent region loss of the 22q11.23 chromosomal region was the most observed chromosomal alteration, followed by losses of chromosomes 14, 1, 6, and 19, polysomies of chromosomes 17, 1q, and 20, and gains of 13q14.2, 10p13, and 21q21.2 chromosomal regions. Based on their CNA profile, RM could be classified into two genetic subgroups with distinct clinicopathologic features characterized by the presence of (1) chromosomal losses only and (2) combined losses and gains of several chromosomes. The latter displays a higher frequency of WHO grade 3 tumors and poorer clinical outcomes.

Cytogenetic Abnormalities for Predicting the Risk of Metastases in Choroidal and Ciliary Body Melanoma.

Purpose: Choroidal melanoma (CM) and ciliary body melanoma (CBM) are the two most common subtypes of uveal melanoma. Starting from the observation that CBM tends to have a higher metastatic potential than CM, we hypothesized that specific cytogenetic abnormalities could be associated with tumor location - reflecting distinct genetic signatures that would drive the risk of distant spread. Methods: Chromosomal alterations were investigated by molecular cytogenetic techniques in 217 and 97 patients with CM and CBM, respectively. Cox proportional hazards regression analysis was used to identify the independent predictors of distant metastasis. Results: Patients with CBM had larger tumor sizes (P < 0.001), higher disease stages (P < 0.001), and more frequently showed distant metastasis (P = 0.002) than those with CM. On analyzing the entire study cohort, we found that specific chromosomal alterations - including chromosome 8p loss (P < 0.001), 1p loss (P < 0.001), and monosomy 3 (P < 0.005) - were independent predictors of distant metastasis. Based on a decision-tree learning algorithm, we identified three specific subgroups of patients with uveal melanoma at high risk of distant spread. Monosomy 3 occurred significantly more frequently in patients with T3 CBM tumors. Conclusions: Specific cytogenetic abnormalities - including chromosome 8p loss, 1p loss, and monosomy 3 - are independent risk factors for distant metastasis in uveal melanoma. Larger tumor size at presentation and monosomy 3 contribute to a higher metastatic risk in patients with CBM.

Clinical features of complex karyotype in newly diagnosed acute myeloid leukemia.

Complex karyotype acute myeloid leukemia (CK-AML) has been classified as an adverse-risk subtype. Although a few reports have further classified CK-AML as typical (including monosomy of chromosomes 5, 7 and 17 or deletion of 5q, 7q and/or 17p) or atypical, the clinical features of these subtypes in Japanese patients remain unclear. We retrospectively analyzed a total of 115 patients with CK-AML, including 77 with typical CK-AML and 38 with atypical CK-AML. Median overall survival (OS) was significantly shorter in patients with typical CK-AML than atypical CK-AML (143 days vs. 369 days, P = 0.009). Among patients with typical CK-AML, those with monosomy 17 or deletion of 17p had significantly shorter OS than patients without such abnormalities (105 days vs. 165 days, P = 0.033). TP53 mutations were more predominant in patients with typical CK-AML than in patients with atypical CK-AML (69.7% vs. 32.4%, P < 0.001). Patients with typical CK-AML had a poor prognosis regardless of TP53 mutation status. Among patients with atypical CK-AML, however, prognosis was worse for those with the TP53 mutation than those without the mutation. In conclusion, prognosis is extremely poor for both typical CK-AML and atypical CK-AML with TP53 mutation.

A prognostic classification system for uveal melanoma based on a combination of patient age and sex, the American Joint Committee on Cancer and the Cancer Genome Atlas models.

PURPOSE: To revisit the independent importance of ciliary body involvement (CBI), monosomy 3 (M3), tumour size, histological and clinical factors in uveal melanoma (UM) and to devise a new prognostic classification based on a combination of the American Joint Committee on Cancer (AJCC) and the Cancer Genome Atlas (TCGA) models. METHODS: Two cohorts with a total of 1796 patients were included. Clinicopathological factors were compared between patients with and without CBI and M3. Development of the prognostic classification was performed in a training cohort and was then tested in two independent validation cohorts. RESULTS: Tumours with CBI were more common in women, had greater apical thickness, greater basal tumour diameter, greater rates of vasculogenic mimicry and greater rates of M3, were more often asymptomatic at diagnosis and had poorer 5- and 10-year globe conservation rates (p < 0.023). In multivariate logistic regression, patient age at diagnosis, tumour diameter and CBI were independent predictors of M3 (p < 0.001). In multivariate Cox regression, male sex, age at diagnosis, tumour diameter, M3 and CBI were independent predictors of metastasis. The proposed prognostic classification combined patient age, sex, CBI, extraocular extension, M3, 8q (optional) and tumour size, and demonstrated greater prognostic acumen than both AJCC 4 T categories and TCGA groups A to D in validation cohorts. CONCLUSIONS: Tumour size does not confound the prognostic implication of CBI, M3, male sex and age at diagnosis in UM. These factors were included in a new prognostic classification that outperforms AJCC T category and TCGA groups.

The effects of estrogen induction therapy on pubertal presentations in turner syndrome patients.

OBJECTIVE: In this study, we investigated various pubertal presentations and progressions before and after estrogen induction therapy and the correlations with Turner syndrome karyotypes. MATERIALS AND METHODS: We reviewed the medical records of patients with Turner syndrome diagnosed before the age of 18 years between 2000 and 2019. Sixty-six patients were enrolled and distributed into 45,X monosomy group, X chromosome structural abnormalities group and X mosaicism group. The pubertal presentations were classified into spontaneous puberty, arrested puberty and no spontaneous puberty. All patients' karyotypes, pubertal progressions and laboratory data were collected and analyzed. RESULTS: The karyotypes were highly correlated with pubertal presentations. No spontaneous puberty was noticed in 58.3% 45,X monosomy patients, 50% patients with X chromosome structural abnormalities had arrested puberty, whereas 70% patients with X mosaicism had spontaneous puberty. Estrogen induction therapy in patients with no spontaneous puberty could induce puberty and the tempo of puberty may approximate to the spontaneous puberty group (median, 2.3 vs. 2.2 years, P = 0.95). In both interventional groups, the FSH level was distinguishable before treatment (median, 65.1 vs. 100.4 mIU/mL, P = 0.02). After long term estrogen therapy, the FSH could be suppressed to similar level in both interventional groups (median, 37.5 vs 34.5 mIU/mL, P = 0.84). Neither LH nor E2 level provided valuable information before and after treatment. CONCLUSION: The karyotypes were highly correlated with pubertal presentations at Turner syndrome patients. The integrity of 2nd X chromosome plays an important role. Low dose estrogen could mimic the tempo of puberty even delay induction age at Taiwan. The FSH data could provide predictive information of pubertal induction for both interventional groups.

Why Turner patients with 45, X monosomy should not be excluded from fertility preservation services.

In this case report, we highlight the practical dilemma, i.e. to perform ovarian tissue cryopreservation surgery in a 45, X Turner Syndrome patient or not, by reporting on the presence of follicles in a 13-year-old female diagnosed with 45, X monosomy and an unmeasurable anti-müllerian hormone serum level. We compare our results with previous research, highlight the challenges we faced in this case and provide recommendations for daily practice. Hereby, we demonstrate that excluding certain subgroups of Turner Syndrome patients (e.g. monosomy patients, and/or girls with an anti-müllerian hormone level below 2.0 ng/l) may be premature, especially based on the current state of published research data. This practical example of a challenging dilemma in the counselling of Turner Syndrome patients for fertility preservation is of interest for clinicians involved in fertility counselling and Turner Syndrome care.

Karyotyping of Lymphocytes and Epithelial Cells of Distinct Embryonic Origin Does Not Help to Predict the Turner Syndrome Features.

BACKGROUND: In Turner syndrome (TS), fluorescent in situ hybridization (FISH) karyotyping offers an alternative to classical karyotyping. OBJECTIVE: We tested the added value of FISH karyotyping from lymphocytes (mesodermal origin), buccal cells (ectodermal origin), and a rear-tongue smear (endodermal origin) to determine the 45,X cell line fraction and its impact on patient phenotype. DESIGN AND PATIENTS: Classical karyotyping and three FISH assays were done in 153 girls and women previously diagnosed with TS in four university hospitals. The 45,X cell line fraction was determined for each method and correlated with the major phenotypic signs. RESULTS: Classical karyotyping identified 45,X/46,XX mosaicism in 77/153 subjects (50%), 45,X monosomy in 52/153 (34%), and other karyotypes in 24/153 (16%). FISH from lymphocytes verified 45,X in 47/52 original cases, whereas 4/52 had 45,X/46,XX and 1/52 45,X/47,XYY mosaicism. The 45,X cell line fraction was higher in FISH from lymphocytes compared to classical karyotyping (median 86.4% vs. 70.0%; p < 0.001), while there was no difference for FISH from buccal or rear-tongue smear cells. The mean 45,X cell line fraction was more abundant in patients with several of the characteristic phenotypic signs compared to patients without them (p < 0.01), but the predictive power was insufficient. CONCLUSION: FISH analysis confirmed the findings of classical karyotyping; only a few 45,X monosomy cases were reclassified as mosaics. The 45,X cell line fraction did not show clinically meaningful prediction of the phenotype. FISH analysis of buccal or rear-tongue epithelial cells may be a non-inferior, less invasive alternative to classical karyotyping.

Variantes citogenéticas en pacientes con síndrome de Turner diagnosticadas en un hospital de tercer nivel de atención en Ecuador / Cytogenetic variants in patients with Turner syndrome diagnosed in a third level care hospital in Ecuador

Resumen Introducción: El Síndrome de Turner (ST) es una alteración cromosómica sexual causada por la ausencia parcial o completa del cromosoma X, además de mosaicismos y otras alteraciones estructurales del cromosoma X o Y; está presente en 1 de 2500 nacidas vivas. Objetivo: Describir las variantes citogenéticas de pacientes con síndrome de Turner y evaluar su asociación con el fenotipo de presentación y la edad del diagnóstico. Método: Estudio retrospectivo de corte transversal de una serie de 82 casos de síndrome de Turner. Los cariotipos fueron realizados utilizando el medio RPMI-1640; las preparaciones de cromosomas se obtuvieron utilizando técnicas estándar y se analizaron mediante bandas GTG con una resolución de 400-450 bandas, donde se contó con 20-50 metafases para reducir la probabilidad de no detección de mosaicismo. Resultados: 45 (55.6%) fueron diagnosticadas, con monosomía clásica del cromosoma X, mientras 29 (35,8%) mostraron anomalías estructurales del cromosoma X y 7 (8,6%) se asociaron a mosaicos numéricos del cromosoma X. Solo 21 (26%) pacientes fueron diagnosticadas por debajo de los 12 años, mientras el resto 60 (74%) se detectaron entre la adolescencia y la adultez. La baja estatura fue una característica universal en todos los grupos de estudio. Conclusiones: Las fórmulas cromosómicas en el síndrome de Turner pueden ser muy variadas y tener diversas implicaciones en el fenotipo; se destaca la baja talla como un criterio clínico relevante en la sospecha clínica.

Abstract Introduction: Turner Syndrome (TS) is a sexual chromosomal alteration caused by the partial or complete absence of the X chromosome, in addition to mosaicisms and other structural alterations of the X or Y chromosome; It is present in 1 in 2,500 live births. Objective: To describe the cytogenetic variants of Turner syndrome patients and to evaluate their association with the phenotype at presentation and age at diagnosis. Methods: Retrospective cross-sectional study of a series of 82 cases of Turner syndrome. Karyotypes were performed using RPMI-1640 medium; Chromosome preparations were obtained using standard techniques and analyzed by GTG banding with a resolution of 400-450 bands where 20-50 metaphases were counted to reduce the probability of missing mosaicism. Results: 45 (55.6%) were diagnosed with classic monosomy of the X chromosome, while 29 (35.8%) showed structural abnormalities of the X chromosome and 7 (8.6%) were associated with numerical mosaics of the X chromosome. Only 21 (26%) patients were diagnosed under 12 years of age, while the rest 60 (74%) were detected between adolescence and adulthood. Short stature was a universal characteristic in all study groups. Conclusions: The chromosomal formulas in Turner syndrome can be variable and have different implications in the phenotype; short stature stands out as a relevant clinical criterion in clinical suspicion.

The impact of monosomies, trisomies and segmental aneuploidies on chromosomal stability.

Aneuploidy and chromosomal instability are both commonly found in cancer. Chromosomal instability leads to karyotype heterogeneity in tumors and is associated with therapy resistance, metastasis and poor prognosis. It has been hypothesized that aneuploidy per se is sufficient to drive CIN, however due to limited models and heterogenous results, it has remained controversial which aspects of aneuploidy can drive CIN. In this study we systematically tested the impact of different types of aneuploidies on the induction of CIN. We generated a plethora of isogenic aneuploid clones harboring whole chromosome or segmental aneuploidies in human p53-deficient RPE-1 cells. We observed increased segregation errors in cells harboring trisomies that strongly correlated to the number of gained genes. Strikingly, we found that clones harboring only monosomies do not induce a CIN phenotype. Finally, we found that an initial chromosome breakage event and subsequent fusion can instigate breakage-fusion-bridge cycles. By investigating the impact of monosomies, trisomies and segmental aneuploidies on chromosomal instability we further deciphered the complex relationship between aneuploidy and CIN.

Trisomy 20p/monosomy 18p associated with congenital bilateral perisylvian syndrome.

We report the association, not previously described, between trisomy 20/ monosomy 18 and congenital bilateral perisylvian syndrome (CBPS), a condition featuring intellectual disability, epilepsy, oro-motor dysfunction and bilateral perisylvian polymicrogyria (BPP) in a 29-year-old individual. Detailed clinical evaluation, long-term EEG and EEG analysis by means of electrical source imaging (ESI), 3T MRI and array-CGH were performed. Clinical examination showed moderate/severe intellectual disability, dysmorphic features, oro-motor dysfunction, short stature, abnormal hands and feet, bradykinesia and abnormal posture. The patient had suffered from drug-resistant epilepsy since infancy. Brain MRI showed that BPP was consistent with CBPS. Additional imaging features revealed corpus callosum and cerebellar hypoplasia and fusion of the C1-C2 vertebrae. Ictal EEG and ESI documented tonic seizures originating from the right polymicrogyric cortex. Facial gestalt included dysmorphic features reported in patients with 18- and 20+ chromosomal rearrangements. Array-CGH showed an unbalanced translocation, arr(18p)x1(20p)x3. In conclusion, we provide a detailed electro-clinical and MRI description of a novel condition characterized by the association between trisomy 20p/monosomy 18p and CBPS, also illustrating its clinical evolution into adulthood. This information may help paediatricians, neurologists and geneticists to better counsel families about the developmental prognosis of this rare unbalanced chromosomal rearrangement.

Differential characteristics of TP53 alterations in pure erythroid leukemia arising after exposure to cytotoxic therapy.

Pure erythroid leukemia (PEL) is a rare acute leukemia with a dismal prognosis. TP53 mutations are a dominant feature of PEL, but the characteristics of TP53 alterations in PEL without prior exposure to cytotoxic therapy (d-PEL) or with such exposure (t-PEL) is unknown. We studied 25 patients with TP53-mutated PEL including 16 d-PEL and 9 t-PEL. Both groups had comparable clinical findings and overall survival. The TP53 mutation, commonly missense, was present in the dominant clone in all cases. In the d-PEL group, 10/16 (62.5%) had one TP53 mutation compared to 8/9 (89%) patients in the t-PEL group. In the d-PEL group, 9/16 (56.2%) patients had hotspot mutations compared to 2 (22.2%) patients in the t-PEL group. Notably, monosomy 17 or del(17p) were less common in the d-PEL group (26.6%) compared to the t-PEL group (71.4%), underscoring distinctive TP53 alterations in d-PEL versus t-PEL, possibly reflecting different fitness advantages.