Implementation and Evaluation of Preimplantation Genetic Testing at Vilnius University Hospital Santaros Klinikos.

Background and Objectives: The most effective treatment of infertility is in vitro fertilization (IVF). IVF with Preimplantation Genetic Testing (PGT) allows to identify embryos with a genetic abnormality associated with a specific medical disorder and to select the most optimal embryos for the transfer. PGT is divided into structural rearrangement testing (PGT-SR), monogenetic disorder testing (PGT-M), and aneuploidy testing (PGT-A). This study mostly analyzes PGT-SR, also describes a few cases of PGT-M. The aim of this study was to implement PGT procedure at Vilnius University Hospital Santaros Klinikos (VUHSK) Santaros Fertility Centre (SFC) and to perform retrospective analysis of PGT procedures after the implementation. Materials and Methods: A single-center retrospective analysis was carried out. The study population included infertile couples who underwent PGT at SFC, VUHSK from January 01st, 2017 to December 31st, 2020. Ion PGM platform (Life Technologies, USA) and Ion ReproSeq PGS View Kit (Life Technologies, USA) were used for the whole genome amplification. Results were assessed using descriptive statistics. Results: PGT was successfully implemented in VUHSK in 2017. During the analyzed time period, thirty-four PGT procedures were performed for 26 couples. Two procedures were performed in 2017, 7 procedures - in 2018, 13 - in 2019, and 12 - in 2020. In comparison with all IVF procedures, 2.5% procedures were IVF with PGT, a highest percentage was in 2020 (3.8% of all procedures). The main indication for PGT was balanced chromosomal rearrangements (in 85.3% cases). In all 34 cases 515 oocytes were aspirated in total, 309 oocytes were fertilized, oocytes fertilization rate exceeded 60%. A normal diploid karyotype was found in 46 (16.8%) biopsied embryos. Out of all PGT procedures, 9 (26.5%) resulted in a clinical pregnancy. Six (66.7%) pregnancies were confirmed in 2019, and 3 (33.3%) - in 2020. Three (33.3%) pregnancies resulted in spontaneous abortion, 6 (66.7%) - in delivery. Conclusions: The implementation of PGT in VUHSK was successful. The most common indication for PGT was a reciprocal translocation. Oocytes fertilization rate exceeded 60%, a normal karyotype was found less than in one-fifth of biopsied embryos. A highest clinical pregnancy rate was achieved in 2019 when almost half of women conceived, which is probably related to the experience gained by the multidisciplinary team. This is the first study analyzing IVF with PGT in Lithuania, however, the results should be interpreted with caution due to a low number of total procedures performed.

The First Live Birth in Lithuania After Application of Preimplantation Genetic Testing.

SUMMARY BACKGROUND: Preimplantation genetic testing (PGT) is a genetic testing procedure that is performed before the implantation of embryos for the identification of genetic abnormalities. It is commonly performed when one or both expecting parents have such abnormalities and are at a high risk of passing them to their offspring. The aim of this case report is to describe the first successful IVF/ICSI/PGT procedure in Lithuania. CASE REPORT: A 27-year-old woman and a 31-year-old man, a married couple, were referred to VUHSK Santaros Fertility Center after trying to conceive for 4 years. In a previous relationship, the woman got pregnant spontaneously and decided to terminate the pregnancy. The husband does not have any children. During the medical examination, the transvaginal ultrasound revealed a low antral follicle count and low anti-Müllerian hormone level for the woman. Semen analysis for the male patient showed severe oligoastenospermia, which confirmed the previous abnormal spermogram results. Chromosome analysis revealed normal karyotype for the woman (46,XX) and Robertsonian translocation for the husband (45,XY,der(13;14)(q10;q10)). After the interdisciplinary medical team counselling, an ICSI with PGT-SR was suggested for the couple. The woman underwent controlled ovarian hyperstimulation with GnRH antagonist protocol for 11 days. Only one embryo with no unbalanced rearrangements was identified and transferred to the woman. On the 14th day post oocyte retrieval, the first serum ß-hCG result was received - 39.5 mIU/ml, and the normal gestational sac at 5 weeks and 3 days was confirmed by ultrasound examination. CONCLUSION: the first successful pregnancy was achieved in Lithuania and the first IVF/ICSI/PGT-SR newborn in Lithuania was born in 2019 - a vaginal birth of a healthy girl with gestational age of 38 weeks and 4 days and a weight of 2820 g; the Apgar score was 10/10. The IVF/ICSI/PGT procedure was successfully implemented by the multidisciplinary team in VUHSK.

Analysis of Lithuanian CYP2D6 polymorphism and its relevance to psychiatric care of the local population.

BACKGROUND: CYP450 system gene CYP2D6 polymorphisms have been associated with an altered response to psychotropic drugs. While there exists interindividual and interethnic differences of clinical significance, there is no data concerning the Lithuanian population. AIMS: To determine the distribution of CYP2D6 alleles and predicted phenotype in the Lithuanian population, compare it to other Europeans and find the differences between patients with affective disorders and the healthy population. METHODS: Our study sample consisted of 179 subjects that included 104 healthy volunteers and 75 patients with clinical diagnosis of affective disorders according to ICD-10AM classification, treated in hospital settings. DNA samples were taken from the blood and alleles of the CYP2D6 gene were determined for each participant. Frequencies were compared to other Europeans. RESULTS: The frequency of the most common alleles *1 and *2 was 45.0% and 28.8% accordingly. Dysfunctional *5 (1 vs. 30, p < .002) allele was less frequent in Lithuania inhabitants than previously established in other Europeans. There were no polymorphisms of the CYP2D6 gene that could be associated with changes in drug metabolism in the patients. The functional CYP2D6 *2 allele was more prevalent in the control group, while the non functional CYP2D6 *4 allele was more prevalent in the patient group (p < .05 for both cases). CONCLUSION: The genetic makeup of Lithuanians was generally comparable to other Europeans, but fewer Lithuanians had non-functional *5 allele. More patients had non-functional alleles. Study findings contradict previous results from other countries, where CYP2D6 gene polymorphism was associated with treatment outcomes.

Complete mtDNA sequencing reveals mutations m.9185T>C and m.13513G>A in three patients with Leigh syndrome.

The most common mitochondrial disorder in children is Leigh syndrome, which is a progressive and genetically heterogeneous neurodegenerative disorder caused by mutations in nuclear genes or mitochondrial DNA (mtDNA). In the present study, a novel and robust method of complete mtDNA sequencing, which allows amplification of the whole mitochondrial genome, was tested. Complete mtDNA sequencing was performed in a cohort of patients with suspected mitochondrial mutations. Patients from Latvia and Lithuania (n = 92 and n = 57, respectively) referred by clinical geneticists were included. The de novo point mutations m.9185T>C and m.13513G>A, respectively, were detected in two patients with lactic acidosis and neurodegenerative lesions. In one patient with neurodegenerative lesions, the mutation m.9185T>C was identified. These mutations are associated with Leigh syndrome. The present data suggest that full-length mtDNA sequencing is recommended as a supplement to nuclear gene testing and enzymatic assays to enhance mitochondrial disease diagnostics.

Clinical, cytogenetic and molecular study of a case of ring chromosome 10.

Ring chromosome 10 is a rare cytogenetic finding. Only a few cases with molecular cytogenetic definition have been reported. We report here on a child with a ring chromosome 10, which is associated with prenatal and postnatal growth retardation, microcephaly, dysmorphic features, hypotonia, heart defect, severe pes equinovarus, and bronchial asthma. The chromosomal aberration was defined by chromosome microarray analysis, which revealed two deletions at 10pter (3.68 Mb) and 10qter (4.26 Mb). The clinical features are very similar to those reported in other clinical cases with ring chromosome 10, excluding bronchial asthma, which has not been previously reported in individuals with ring chromosome 10.