ABSTRACT
PURPOSE: To present the developed preimplantation genetic testing (PGT) for spinocerebellar ataxia type 1 (SCA1) and the outcomes of IVF with PGT. METHODS: PGT was performed for two unrelated couples from the Republic of Sakha (Yakutia) with the risk of SCA1 in one spouse. We have developed a system for PGT of a monogenic disease (PGT-M) for SCA1, which includes the analysis of a panel of 11 polymorphic STR markers linked to the ATXN1 gene and a pathogenic variant of the ATXN1 gene using nested PCR and fragment analysis. IVF/ICSI programs were performed according to standard protocols. Multiple displacement amplification (MDA) was used for whole genome amplification (WGA) and array comparative genomic hybridization (aCGH) for aneuploidy testing (PGT-A). RESULTS: Eight STRs were informative for the first couple and ten for the second. Similarity of the haplotypes carrying pathogenic variants of the ATXN1 gene was noted. In the first case, during IVF/ICSI-PGT, three embryos reached the blastocyst stage and were biopsied. One embryo was diagnosed as normal by maternal STR haplotype and the ATXN1 allele. PGT-A revealed euploidy. The embryo transfer resulted in a singleton pregnancy, and a healthy boy was born. Postnatal diagnosis confirmed normal ATXN1. In the second case, two blastocysts were biopsied. Both were diagnosed as normal by PGT-M, but PGT-A revealed aneuploidy. CONCLUSION: Birth of a healthy child after PGT for SCA1 was the first case of successful preimplantation prevention of SCA1 for the Yakut couple and the first case of successful PGT for SCA1 in Russia.
Subject(s)
Ataxin-1 , Microsatellite Repeats , Preimplantation Diagnosis , Spinocerebellar Ataxias , Humans , Spinocerebellar Ataxias/genetics , Spinocerebellar Ataxias/pathology , Spinocerebellar Ataxias/diagnosis , Female , Ataxin-1/genetics , Male , Adult , Pregnancy , Microsatellite Repeats/genetics , Genetic Testing , Comparative Genomic Hybridization , Aneuploidy , Fertilization in Vitro , Embryo TransferABSTRACT
Dysregulation of the oxidant-antioxidant system contributes to the pathogenesis of cerebral stroke (CS). Epigenetic changes of redox homeostasis genes, such as glutamate-cysteine ligase (GCLM), glutathione-S-transferase-P1 (GSTP1), thioredoxin reductase 1 (TXNRD1), and myeloperoxidase (MPO), may be biomarkers of CS. In this study, we assessed the association of DNA methylation levels of these genes with CS and clinical features of CS. We quantitatively analyzed DNA methylation patterns in the promoter or regulatory regions of 4 genes (GCLM, GSTP1, TXNRD1, and MPO) in peripheral blood leukocytes of 59 patients with CS in the acute phase and in 83 relatively healthy individuals (controls) without cardiovascular and cerebrovascular diseases. We found that in both groups, the methylation level of CpG sites in genes TXNRD1 and GSTP1 was ≤ 5%. Lower methylation levels were registered at a CpG site (chr1:94,374,293, GRCh37 [hg19]) in GCLM in patients with ischemic stroke compared with the control group (9% [7%; 11.6%] (median and interquartile range) versus 14.7% [10.4%; 23%], respectively, p < 0.05). In the leukocytes of patients with CS, the methylation level of CpG sites in the analyzed region of MPO (chr17:56,356,470, GRCh3 [hg19]) on average was significantly lower (23.5% [19.3%; 26.7%]) than that in the control group (35.6% [30.4%; 42.6%], p < 0.05). We also found increased methylation of MPO in smokers with CS (27.2% [23.5%; 31.1%]) compared with nonsmokers with CS (21.7% [18.1%; 24.8%]). Thus, hypomethylation of CpG sites in GCLM and MPO in blood leukocytes is associated with CS in the acute phase.
