Trisomy 21 with Maternally Inherited Balanced Translocation (15q;22q) in a Female Fetus: A Rare Case of Probable Interchromosomal Effect.

Chromosomal rearrangements can interfere with the disjunction and segregation of other chromosome pairs not involved in the rearrangements, promoting the occurrence of numerical abnormalities in resulting gametes and predisposition to trisomy in offspring. This phenomenon of interference is known as the interchromosomal effect (ICE). Here we report a prenatal case potentially generated by ICE. The first-trimester screening ultrasound of the pregnant woman was normal, but the NIPT indicated a high risk for three copies of chromosome 21, thus suspecting trisomy 21 (T21). After a comprehensive clinical evaluation and genetic counseling, the couple decided to undergo amniocentesis. The prenatal karyotype confirmed T21 but also showed a balanced translocation between the long arm of chromosome 15 (q22) and the long arm of chromosome 22. The parents' karyotypes also showed that the mother had the 15;22 translocation. We reviewed T21 screening methods, and we performed a literature review on ICE, a generally overlooked phenomenon. We observed that ours is the first report of a prenatal case potentially due to ICE derived from the mother. The recurrence risk of aneuploidy in the offspring of translocated individuals is likely slightly increased, but it is not possible to estimate to what extent. In addition to supporting observations, there are still open questions such as, how frequent is ICE? How much is the aneuploidy risk altered by ICE?

Clinical exome-based panel testing for medically actionable secondary findings in a cohort of 383 Italian participants.

Background: Next-generation sequencing-based genetic testing represents a great opportunity to identify hereditary predispositions to specific pathological conditions and to promptly implement health surveillance or therapeutic protocols in case of disease. The term secondary finding refers to the active search for causative variants in genes associated with medically actionable conditions. Methods: We evaluated 59 medically actionable ACMG genes using a targeted in silico analysis of clinical exome sequencing performed in 383 consecutive individuals referred to our Medical Genetics Unit. A three-tier classification system of SFs for assessing their clinical impact and supporting a decision-making process for reporting was established. Results: We identified SFs with high/moderate evidence of pathogenicity in 7.0% (27/383) of analyzed subjects. Among these, 12/27 (44.4%) were carriers of a high-risk recessive disease allele. The most represented disease domains were cancer predisposition (33.3%), cardiac disorders (16.7%), and familial hypercholesterolemia (12.5%). Conclusion: Although still debated, ensuring during NGS-based genetic testing an opportunistic screening might be valuable for personal and familial early management and surveillance of medically actionable disorders, the individual's reproductive choices, and the prevalence assessment of underestimated hereditary genetic diseases.

Complex Modes of Inheritance in Hereditary Red Blood Cell Disorders: A Case Series Study of 155 Patients.

Hereditary erythrocytes disorders include a large group of conditions with heterogeneous molecular bases and phenotypes. We analyzed here a case series of 155 consecutive patients with clinical suspicion of hereditary erythrocyte defects referred to the Medical Genetics Unit from 2018 to 2020. All of the cases followed a diagnostic workflow based on a targeted next-generation sequencing panel of 86 genes causative of hereditary red blood cell defects. We obtained an overall diagnostic yield of 84% of the tested patients. Monogenic inheritance was seen for 69% (107/155), and multi-locus inheritance for 15% (23/155). PIEZO1 and SPTA1 were the most mutated loci. Accordingly, 16/23 patients with multi-locus inheritance showed dual molecular diagnosis of dehydrated hereditary stomatocytosis/xerocytosis and hereditary spherocytosis. These dual inheritance cases were fully characterized and were clinically indistinguishable from patients with hereditary spherocytosis. Additionally, their ektacytometry curves highlighted alterations of dual inheritance patients compared to both dehydrated hereditary stomatocytosis and hereditary spherocytosis. Our findings expand the genotypic spectrum of red blood cell disorders and indicate that multi-locus inheritance should be considered for analysis and counseling of these patients. Of note, the genetic testing was crucial for diagnosis of patients with a complex mode of inheritance.

Impact of Chamber Dilatation on the Prognostic Value of Left Ventricular Geometry in Hypertension.

BACKGROUND: The different geometric patterns of the left ventricle may or may not coexist with chamber dilatation. The prognostic impact of such a combination is unclear. METHODS AND RESULTS: We studied a cohort of 2635 initially untreated patients with hypertension, mean age 50 years. At entry, 24-hour ambulatory blood pressure progressively increased across the patterns of normal geometry, concentric left ventricular (LV) remodeling, eccentric nondilated LV hypertrophy (LVH), eccentric dilated LVH, concentric nondilated LVH, and concentric dilated LVH. During a mean follow-up of 9.7 years, 360 patients developed a first major cardiovascular event at a rate (×100 patient-years) of 1.41. The event rate was 0.93 in the group with normal LV geometry, 1.10 in the group with LV concentric remodeling, 1.40 in the group with nondilated eccentric LVH, 2.10 in the group with eccentric dilated LVH, 2.34 in the group with nondilated concentric LVH, and 4.67 in the group with dilated concentric LVH (log-rank test: P<0.001). In a Cox model, after adjustment for several independent covariables (age, sex, diabetes mellitus, current smoking, total cholesterol, estimated glomerular filtration rate, and average 24-hour systolic blood pressure), concentric dilated LVH was associated with a 98% excess risk of cardiovascular events (P=0.0037). However, LV geometric pattern lost statistical significance when LV mass was entered into the model. CONCLUSIONS: In initially untreated patients with hypertension, LV dilatation adds an adverse prognostic burden to the patterns of eccentric and concentric LVH. This phenomenon is explained by the greater LV mass associated with LV chamber dilatation.

Safety of dabigatran in an elderly population: single center experience in Italy.

In clinical practice, adherence to drugs and their safety may differ from randomised controlled trial settings. This study was undertaken to investigate the adherence to dabigatran, a direct thrombin inhibitor, and its safety in a real-world setting. We studied a prospective cohort of 114 elderly consecutive patients with non valvular atrial fibrillation (AF) who were treated with dabigatran 150 mg twice-daily (N=39) or 110 mg twice-daily (N=76). These patients were studied at baseline and after an average of 6 months. Mean age was 80 years and 53% were women. At entry, the average CHA2DS2VASc score was 4 and the HAS-BLED score was 2. AF was permanent in 49% of patients, persistent in 30%, paroxysmal in 12% and new-onset in 24%. In the follow-up clinical visit we ascertained vital status, adherence to treatment according to refill prescription orders, and side effects. Adherence was ≥80% in 76.5% of patients. Heartburn, the most frequent adverse effect, was reported by 25 patients (22%). Major and minor bleedings were experienced by 2 (1.8%) and 9 (7.9%) patients, respectively. Permanent discontinuation occurred in 18 patients (16%). The most frequent cause of permanent discontinuation was heartburn (10 patients). This real-life study suggests that safety of dabigatran and adherence to this drug in an elderly cohort of AF patients at high or very high risk of thromboembolism are generally good. Heartburn is the main cause of treatment discontinuation.