Implication of Genetic Testing and Pregnancy Outcome in a Woman with Unbalanced Translocation t(1;6)

Case series

Patients:—

Final Diagnosis: 1p36 deletion • duplication 1p36.31 (0.22 Mb) and deletion 6q27 (1.2 Mb) • duplication 1p36.33p36.31 (5.4Mb) and deletion 6q27 (1.2 Mb) • unbalanced translocation t(1;6)

Symptoms: Multiple adverse pregnancy outcome

Medication: —

Clinical Procedure: —

Specialty: Genetics • Obstetrics and Gynecology

A novel EDA variant causing X-linked hypohidrotic ectodermal dysplasia: Case report

Hereditary ectodermal dysplasias are a complex group of inherited disorders characterised by abnormalities in two or more ectodermal derivatives (skin, nails, sweat glands, etc.). There are two main types of these disorders – hidrotic and hypohidrotic/anhidrotic ectodermal dysplasias. Hypohidrotic ectodermal dysplasia (HED) or Christ-Siemens-Touraine syndrome (OMIM: 305100) occurs in 1 out of 5000–10,000 births [19] and has an X-linked recessive inheritance pattern (X-linked hypohydrotic ectodermal dysplasia – XLHED) [2].

The main cause of XLHED is a broad range of pathogenic variants in the EDA gene (HGNC:3157, Xq12-13) which encodes the transmembrane protein ectodysplasin-A [4]. We report here the case of a patient with a novel inherited allelic variant in the EDA gene – NM_001399.5:c.337C>T (p.Gln113*) – in the heterozygous state. Targeted family member screening was conducted and other carriers of this EDA gene pathogenic variant were identified and phenotypically characterised. The patient subsequently underwent in vitro fertilisation with preimplantation genetic testing for monogenic diseases (PGT-M).

The outcomes after transfers of embryos with chromosomal mosaicism: a single reproductive medicine center experience at iVF Riga clinic

Aim: The aim of this study is to summarize the outcomes of transfers of mosaic embryos, which were classified according to guidelines and in strong collaboration of reproductologists, clinical geneticists and patients approved as suitable for transfer. Material and Methods: Retrospective data were collected from 70 patients from a private IVF center to whom embryos with mosaic changes in chromosomal material were transferred from 2015 to 2019. Results and Conclusion: Implantation outcomes and continuing pregnancies showed slight differences, when compared to fully normal embryos. Artifacts have to be differentiated from undeniable aberrations, and correct interpretation of results must be done with following patient counselling and prenatal testing if necessary.

The application of PGT-A for carriers of balanced structural chromosomal rearrangements

The aim of this study was to analyze differences in chromosomal aberrations and euploidy in embryos of each translocation type and gender of carrier in the case series of 10 couples with balanced translocations who underwent IVF with embryos trophectoderm (TE) biopsy and PGT-A to detect chromosomal aberrations. This is a Case Series (Retrospective study). In each case, controlled ovarian hyperstimulation, oocyte insemination with intracytoplasmic sperm injection (ICSI) and cultivation gave multiple blastocysts, that underwent trophectoderm (TE) biopsy with PGT-A analysis using aCGH and NGS. Number of total unbalanced translocations compared to the number of sporadic aneuploid embryos was 39.6% to 39.6% (50% to 50% of all 37 aneuploid embryos). The highest euploidy rate was in male carrier group - 26.7% and the lowest in the Robertsonian translocation carrier group - 18.2%. Sporadic aneuploidy - 68.2% was highest in Robertsonian translocation carrier group and lowest in female group - 11.1%. Chromosomal aberrations related to translocation were highest in female carrier group - 77.8% and lowest in Robertsonian translocation carrier group - 13.6%. Our study showed that expectancy of total embryo aneuploidy rates will be higher in carriers, than in people with normal karyotype. The prevalence of chromosomal aberrations related to translocation was 4.5 times higher in Reciprocal carrier group than in Robertsonian translocation carrier group. Among maternal and paternal carrier groups, the embryos from female carriers had the lowest euploidy rate, unbalanced translocation rate 4.7 times higher than in the male carrier group and higher total aneuploidy rates.