Cytogenetic Analysis of Sporadic First-Trimester Miscarriage Specimens Using Karyotyping and QF-PCR: A Retrospective Romanian Cohort Study

It is well known that first-trimester miscarriages are associated with chromosome abnormalities, with numerical chromosome abnormalities being the ones most commonly detected. Conventional karyotyping is still considered the gold standard in the analysis of products of conception, despite the extended use of molecular genetic techniques. However, conventional karyotyping is a laborious and time-consuming method, with a limited resolution of 5-10 Mb and hampered by maternal cell contamination and culture failure. The aim of our study was to assess the type and frequency of chromosomal abnormalities detected by conventional karyotyping in specimens of sporadic first-trimester miscarriages in a Romanian cohort, using QF-PCR to exclude maternal cell contamination. Long-term cultures were established and standard protocols were applied for cell harvesting, slide preparation, and GTG banding. All samples with 46,XX karyotype were tested for maternal cell contamination by QF-PCR, comparing multiple microsatellite markers in maternal blood with cell culture and tissue samples. Out of the initial 311 specimens collected from patients with sporadic first-trimester miscarriages, a total of 230 samples were successfully analyzed after the exclusion of 81 specimens based on unsuitable sampling, culture failure, or QF-PCR-proven maternal cell contamination. Chromosome abnormalities were detected in 135 cases (58.7%), with the most common type being single autosomal trisomy (71/135-52.6%), followed by monosomy (monosomy X being the only one detected, 24/135-17.8%), and polyploidy (23/135-17.0%). The subgroup analysis based on maternal age showed a statistically significant higher rate of single trisomy for women aged 35 years or older (40.3%) compared to the young maternal age group (26.1%) (p = 0.029). In conclusion, the combination of conventional karyotyping and QF-PCR can lead to an increased chromosome abnormality detection rate in first-trimester miscarriages. Our study provides reliable information for the genetic counseling of patients with first-trimester miscarriages, and further large-scale studies using different genetic techniques are required.

The Phenotypic Spectrum of 15q13.3 Region Duplications: Report of 5 Patients

Chromosome 15q13.3 microduplications are associated with a wide spectrum of clinical presentations ranging from normal to different neuropsychiatric conditions, such as developmental delay (DD), intellectual disability (ID), epilepsy, hypotonia, autism spectrum disorders (ASD), attention-deficit hyperactivity disorder, and schizophrenia. The smallest region of overlap for 15q13.3 duplications encompasses the Cholinergic Receptor Nicotinic Alpha 7 Subunit (CHRNA7) gene, a strong candidate for the behavioral abnormalities. We report on a series of five patients with 15q13.3 duplications detected by chromosomal microarray. The size of the duplications ranged from 378 to 537 kb, and involved the CHRNA7 gene in all patients. The most common clinical features, present in all patients, were speech delay, autistic behavior, and muscle hypotonia; DD/ID was present in three patients. One patient presented epileptic seizures; EEG anomalies were observed in three patients. No consistent dysmorphic features were noted. Neuroimaging studies revealed anomalies in two patients: Dandy-Walker malformation and a right temporal cyst. 15q13.3 duplications are associated with various neuropsychiatric features, including speech delay, hypotonia, ASD, and ID, also present in our patient group. Our study brings detailed clinical and molecular data from five ASD patients with 15q13.3 microduplications involving the CHRNA7 gene, contributing to the existing knowledge about the association of 15q13.3 duplications with neuropsychiatric phenotypes.

The psychiatric phenotype of 15q11.2-q13.3 duplications

Introduction

15q11.2-q13.3 region is prone to genomic rearrangements leading to both deletions and duplications. A wide spectrum of neuropsychiatric conditions, such as developmental delay/intellectual disability (DD/ID), autism, attention-deficit hyperactivity disorder, schizophrenia, epilepsy was reported in association with genomic imbalances of this region.

Objectives

In this paper we report on 9 children carrying 15q11.2-q13.3 duplications.

Methods

Seven boys and two girls, aged 15 months to 15 years, were included in the study. Genomic investigations were carried out by array-based comparative genomic hybridization (Agilent Technologies). In all patients the psychomotor development, dysmorphic features, neuroimaging and EEG anomalies were assessed. Psychologic and psychiatric evaluation was performed with specific tests.

Results

The size of the duplications ranged from 9.65 Mb to 0.38 Mb. All patients presented speech delay. Autistic behavior and muscular hypotonia were detected in 8 out of 9 patients, DD/ID in 6. Two children presented epileptic seizures, in addition 4 other children had EEG anomalies. Facial dysmorphic features were observed in 5 patients. Neuroimaging studies showed anomalies in 4 children. The smallest region of overlap in our patient group harbors CHRNA7 gene, a candidate for the behavioral abnormalities.

Conclusions

15q duplications encompassing CHRNA7 gene were associated with different neuropsychiatric features in our patients. Our results further support the association of 15q duplications with neuropsychiatric phenotypes, with clinical heterogeneity and variable severity, which is yet to be explained. Acknowledgment: The research leading to these results has received funding from the EEA RO NO Grant 2014-2021, the project contract No 6/2019.

Disclosure

No significant relationships.

The influence of orthodontic bracket base diameter and mesh size on bond strength

Previous studies have shown that the size of the foil mesh and surface area of the bracket base correlated to bond strength to tooth enamel. The purpose of this study was to investigate the in vitro shear bond strength (SBS) of orthodontic brackets with 80 and 100 gauge mesh bases as well as mini and standard size bases. Eighty extracted human premolar teeth were randomly allocated into four groups of twenty teeth each. Premolar brackets of different mesh and bracket base area sizes were bonded to the enamel with a conventional 'two paste' orthodontic bonding agent. The SBS was determined and the bond failure sites were assessed using light-optical microscope and SEM. Bond failure occurred in all groups primarily at the bracket/adhesive interface. Mean values for SBS were 9.97 +/- 2.94 MPa and 10.72 +/- 2.54 MPa for 80 gauge mini and standard size respectively, and 10.45 +/- 3.27 MPa and 11.39 +/- 3.32 MPa for 100 gauge mini and standard size. A one-way ANOVA and an unpaired t-test revealed no significant difference in mean SBS (P > 0.05) between 80 and 100 gauge mini and standard size brackets, and no significant difference in mean SBS between brackets of the same surface area with a different gauge mesh size. The clinical relevance of this finding is that the clinician can select smaller brackets with no reduction in effectiveness of the treatment procedure.

Tissue response to hafnium

The aim of the present experimental study was to evaluate the tissue response to hafnium (Hf) a reactive metal closely related to titanium (Ti) and zirconium (Zr). Hf has not been previously evaluated as implant material in a biologic environment. In a first experiment, 21 machined Hf non-threaded implants (test) and 21 similar Ti implants (control) were inserted in the abdominal wall of 21 rats. Animals were sacrificed after 8 days (6 rats), 6 (7 rats) and 12 weeks (8 rats). In a second experiment, 18 rabbits received 18 Hf and 18 Ti threaded implants in their tibiae, one implant in each tibia. The rabbits were sacrificed after 6, 12 and 24 weeks (6 animals/time interval). The bulk metal of the abdominal wall implants, embedded together with the surrounding tissue, was electrolytically dissolved and semithin (1 microm) sections of the intact tissue-implant interface were evaluated by light microscopy (morphometry). Bone-implant contact and bone area within threads were evaluated in ground sections. In soft tissues, a fluid space containing predominantly monocytes/macrophages surrounded the abdominal implants at 8 days. At 6 and 12 weeks, a fibrous capsule, consisting of layers of macrophages and fibroblasts, surrounded the implants. Macrophages, including multinuclear giant cells, always formed the innermost layer in contact with the implant surface. No quantitative or qualitative difference in the tissue organization was detected between Ti and Hf implants. In rabbits, 6 weeks after insertion, the proximal two threads located within the cortical bone were filled with bone in contact with Hf and Ti. The distal threads contained bone marrow. After 12 and 24 weeks, mature bone was present in the proximal 3-4 implant threads. No statistically significant difference was found between Hf and Ti implants at any time periods. It is concluded that Hf is an interesting metal for biomedical applications in bone and soft tissue.

Morbus odontologicus studenticus

Several case reports are described of the disease called "Morbus Odontologicus Studenticus". A widely spread disease often seen amongst young people after they have graduated from high school. It is a combination of predisposed psychological and physiological factors which can lead to severe brain-damage (boredom, bewilderment).