Case report: Detection of fetal trisomy 9 mosaicism by multiple genetic testing methods: Report of two cases

Non-Mosaic Trisomy 9: Further Delineation of the Clinical Phenotype

Non-mosaic trisomy 9 (NMTS9) is a rarely described chromosomal abnormality because most affected pregnancies result in first trimester spontaneous abortions, although survival to delivery is possible. In contrast, the phenotypic features of mosaic trisomy 9 have been well described in the literature as these individuals can survive to birth and beyond. Therefore, a better understanding of the phenotypic spectrum of NMTS9 is needed to provide appropriate perinatal counseling. The phenotype from three fetal and one neonatal case of NMTS9, as defined by chromosome analysis in multiple tissues, is consistent with the existing literature and includes narrow forehead, midface hypoplasia, microphthalmia, clouded corneas, blepharophimosis, rounded nasal tip, broad/prominent nasal bridge, low-set ears with and without malformations, short and broad neck, cerebellar abnormalities, a wide range of cardiac anomalies including ventricular and atrial septal defects as well as valve dysplasia, congenital diaphragmatic hernia, hydronephrosis, and hypoplastic genitalia, multiple contractures, multiple dislocations, and talipes equinovarus. We also report an expansion of the cardiac, genitourinary, and renal phenotypes. This combined phenotype based on prenatal imaging and fetal/postnatal autopsy further delineates the clinical phenotype of NMTS9.

Detection of trisomy 9 mosaicism in the second trimester screening by abnormal level of biochemical markers

Trisomy 9 is a rare chromosomal abnormality that occurs in both mosaic and non-mosaic states. The present study reports a case of mosaic trisomy 9 detected during pregnancy in a 41-year-old woman in the second trimester screening. Maternal serum screening results were used to diagnose a chromosomal abnormality in utero. The results were validated by karyotyping. High levels of alpha-fetoprotein and low levels of unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and inhibin A indicate a high risk for chromosomal abnormalities, including trisomy 18. Amniotic fluid karyotyping revealed 47, XX, +9 (30)/46, XX (20) in the fetus. Because a high level (60%) of mosaicism for trisomy 9 in the fetus can affect many parts of the body, the pregnancy was terminated. It seems that a significant reduction in the levels of hCG and uE3 is an informative marker for the detection of chromosomal abnormalities such as trisomy 9.

The Impact of Chromosomal Mosaicisms on Prenatal Diagnosis and Genetic Counseling-A Narrative Review

Genetic disorders represent a high-impact diagnosis for both patients and their families. Prenatal screening methods and, when recommended, genetic testing allow parents to make informed decisions about the course a pregnancy is going to take. Although offering certainty about the potential evolution and prognosis of the pregnancy, and then the newborn, is usually not possible, genetic counseling can offer valuable insights into genetic disorders. Chromosomal mosaicisms are genetic anomalies that affect only some cell lines in either the fetus or the placenta or both. They can affect autosomal or heterosomal chromosomes, and they can be either numerical or structural. The prognosis seems to be more severe if the genetic alterations are accompanied by malformations visible in ultrasounds. Several genetic techniques can be used to diagnose certain mosaicisms, depending on their nature. A novel approach in prenatal care is non-invasive prenatal screening (NIPS), also known as non-invasive prenatal testing (NIPT), which, although it does not always have diagnostic value, can provide valuable information about potential genetic anomalies, especially numerical, with high sensitivity (Se).

Molecular Characterization and Establishment of a Prognostic Model Based on Primary Immunodeficiency Features in Association with RNA Modifications in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Although immunotherapy is effective for some patients, most find it difficult to benefit from it. This study aims to explore the impact of specific immune pathways and their regulated molecular mechanisms in TNBC. The gene expression data of breast cancer patients were obtained from the TCGA and METABRIC databases. Gene set variation analysis (GSVA) revealed specific upregulation or abnormal expression of immunodeficiency pathways in TNBC patients. Multi-omics data showed significant differential expression of Primary Immunodeficiency Genes (PIDGs) in TNBC patients, who are prone to genomic-level variations. Consensus clustering was used in two datasets to classify patients into two distinct molecular subtypes based on PIDGs expression patterns, with each displaying different biological features and immune landscapes. To further explore the prognostic characteristics of PIDGs-regulated molecules, we constructed a four-gene prognostic PIDG score model and a nomogram using least absolute shrinkage and selection operator (LASSO) regression analysis in combination with clinicopathological parameters. The PIDG score was closely associated with the immune therapy and drug sensitivity of TNBC patients, providing potential guidance for clinical treatment. Particularly noteworthy is the close association of this scoring with RNA modifications; patients with different scores also exhibited different mutation landscapes. This study offers new insights for the clinical treatment of TNBC and for identifying novel prognostic markers and therapeutic targets in TNBC.

Case report: A case report and literature review of complete trisomy 9

Complete trisomy 9 is a rare and lethal chromosomal anomaly characterized by multisystem dysmorphism and central nervous system (CNS) malformations. This study presents a case of complete trisomy 9 with an unusual phenotypic association and investigates the genetic pathways involved in this chromosomal abnormality. Trisomy 9 leads to a wide range of organ abnormalities, and this research contributes to a better understanding of the phenotype associated with this rare aneuploidy. The literature on the phenotypes of fetuses with various systems affected by complete trisomy 9 was reviewed and summarized. Correct diagnosis and appropriate counseling based on the characteristics of previous reports of fetuses with trisomy 9 is essential in maternity care and clinical management. To provide guidance and help for clinical diagnosis, this study aimed to explore the clinical and genetic characteristics of trisomy 9 syndrome to improve clinicians' understanding of the disease.