What proportion of embryos should be considered for transfer following a mosaic diagnosis? A study of 115 clinics from a central diagnostic laboratory.

Purpose: The aim of this study is to identify what proportion of mosaic embryo diagnoses should be considered for transfer, and thereby assess the impact on patient cases.

Methods: We categorised mosaic embryos into 3 groups; high, medium and low priority for transfer based on the percentage of biopsy sample being aneuploid and the chromosomes involved. The categories were applied to those patients that had no euploid embryo diagnoses but 1 or more mosaic embryos identified as mosaic available after PGT-A.

Detailed investigation into the cytogenetic constitution and pregnancy outcome of replacing mosaic blastocysts detected with the use of high-resolution next-generation sequencing.

Objective: To determine the pregnancy outcome potential of mosaic embryos, detected by means of preimplantation genetic screening (PGS) with the use of next-generation sequencing (NGS).

Design: Retrospective study.

Setting: Genetics laboratories.

Rescue of the abnormal skeletal phenotype in Ts65Dn Down syndrome mice using genetic and therapeutic modulation of trisomic Dyrk1a.

Trisomy 21 causes skeletal alterations in individuals with Down syndrome (DS), but the causative trisomic gene and a therapeutic approach to rescue these abnormalities are unknown. Individuals with DS display skeletal alterations including reduced bone mineral density, modified bone structure and distinctive facial features. Due to peripheral skeletal anomalies and extended longevity, individuals with DS are increasingly more susceptible to bone fractures.

Abnormal mineralization of the Ts65Dn Down syndrome mouse appendicular skeleton begins during embryonic development in a Dyrk1a-independent manner.

The relationship between gene dosage imbalance and phenotypes associated with Trisomy 21, including the etiology of abnormal bone phenotypes linked to Down syndrome (DS), is not well understood. The Ts65Dn mouse model for DS exhibits appendicular skeletal defects during adolescence and adulthood but the developmental and genetic origin of these phenotypes remains unclear. It is hypothesized that the postnatal Ts65Dn skeletal phenotype originates during embryonic development and results from an increased Dyrk1a gene copy number, a gene hypothesized to play a critical role in many DS phenotypes.

Non-trisomic homeobox gene expression during craniofacial development in the Ts65Dn mouse model of Down syndrome.

Trisomy 21 in humans causes cognitive impairment, craniofacial dysmorphology, and heart defects collectively referred to as Down syndrome. Yet, the pathophysiology of these phenotypes is not well understood. Craniofacial alterations may lead to complications in breathing, eating, and communication.

Disruption of bone development and homeostasis by trisomy in Ts65Dn Down syndrome mice.

Down syndrome (DS) is a genetic disorder resulting from trisomy 21 that causes cognitive impairment, low muscle tone and craniofacial alterations. Morphometric studies of the craniofacial and appendicular skeleton in individuals with DS suggest that bone development and homeostasis are affected by trisomy. The Ts65Dn mouse model has three copies of approximately half the genes found on human chromosome 21 and exhibits craniofacial skeletal and size differences similar to those observed in humans with DS.

Embryonic and not maternal trisomy causes developmental attenuation in the Ts65Dn mouse model for Down syndrome.

Trisomy 21 results in Down syndrome (DS) and causes phenotypes that may result from alterations of developmental processes. The Ts65Dn mouse is the most widely used genetic and phenotypic model for DS. We used over 1,500 offspring from Ts65Dn and two nontrisomic genetically similar control strains to investigate the influence of trisomy on developmental alterations and number of offspring.