RESUMO
Numeric sex chromosome abnormalities are commonly associated with an increased cancer risk. Here, we report a 14-year-old boy with a rare mosaic 45, X/48, XYYY karyotype presenting with subtle dysmorphic features and relative height deficiency, requiring growth hormone therapy. As only 12 postnatal cases have been described so far with very limited follow-up data, to assess the proband's long-term prognosis, including cancer risk, we performed high-throughput single-cell RNA sequencing (scRNA-seq) analysis. Although comprehensive cytogenetic analysis showed seemingly near perfect balance between 45, X and 48, XYYY cell populations, scRNA-seq revealed widespread differences in genotype distribution among immune cell fractions, specifically in monocytes, B- and T-cells. These results were confirmed at DNA level by digital-droplet PCR on flow-sorted immune cell types. Furthermore, deregulation of predominantly autosomal genes was observed, including TCL1A overexpression in 45, X B-lymphocytes and other known genes associated with hematological malignancies. Together with the standard hematological results, showing increased fractions of monocytes and CD4+/CD8+T lymphocytes ratio, long-term personalized hemato-oncological surveillance was recommended in the reported patient.
Assuntos
Neoplasias , Masculino , Humanos , Adolescente , Cariotipagem , Cariótipo , Medição de Risco , Análise de Sequência de RNARESUMO
Cytogenetic analysis of 75 clear cell renal cell carcinomas (RCC) from adult patients revealed abnormal karyotypes in 59 (79%) tumors. Among structural abnormalities, the most frequent were deletions and unbalanced translocations leading to loss of 3p (found in 68% of karyotypically abnormal tumors), followed by rearrangements of chromosomes 5 (in 37%) and 1 (in 20%). Fifteen unbalanced interchromosomal rearrangements and one reciprocal translocation have not been hitherto reported in clear cell RCC. The most common numerical aberrations were trisomy 7, seen in 44% of tumors, and loss of chromosome Y, detected in 48% of RCCs diagnosed in male patients. In 25 tumors, loss of heterozygosity (LOH) analysis was performed using five polymorphic markers spanning region 3p13-p25. LOH was identified in 10 RCCs with 3p loss detected cytogenetically and 4 karyotypically aberrant tumors without cytogenetic rearrangements of 3p; no LOH was found in 3 tumors with 3p loss seen at the cytogenetic level. Overall, 3p loss was detected by cytogenetic and/or LOH analyses in 75% of RCCs with abnormal karyotype studied. The presence or absence of 3p loss did not correlate with tumor size, nodal involvement, tumor grade or its ability to metastasize. However, karyotypes of metastasizing tumors contained more aberrations than those of non-metastasizing RCCs (5.5 versus 2.9 aberrations per tumor, respectively), and -14/14q-, -17 and -10 were significantly more frequent in metastasizing tumors, suggesting that these aberrations might contribute to the progression of RCC. One patient had t(X;1)(p11.2;p34) as a sole abnormality in the stemline. This is the sixth case with this translocation reported to date. Together with our case, all but 1 RCC with t(X;1)(p11.2;p34) had morphology with a clear cell component, which contrasts these RCCs from tumors harboring t(X;1)(p11.2;q21) that largely had papillary morphology.