Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison

We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body

Analysis of the CYP21A2 gene pathogenic variants in CAH patients from Surgut using next-generation sequencing (NGS)

Abstract Background 21-hydroxylase deficiency is present in 90–95% of cases of congenital adrenal hyperplasia (CAH). Eleven major pathogenic variants account for 93% of all identified variants in the CYP21A2 gene in various clinical forms of the disease. Each population has its own range of significant pathogenic variants. We aimed to study the frequency of pathogenic variants in the CYP21A2 gene using NGS technology and real-time PCR in Surgut patients with different clinical forms of CAH. NGS was performed on 70 patients with salt-wasting and non-classical clinical forms of 21-hydroxylase deficiency, verified by direct Sanger sequencing and PCR–RFLP analysis. Results Eleven different pathogenic variants were found in 68.57% (48/70) of patients. Among 92.86% (13/14) of patients with salt-wasting CAH, variants were found to be homozygous, with CYP21A2 gene deletion as the most frequent mutation (46.4% or 13/28 alleles). In the group with non-classical CAH, pathogenic variants were identified only in 60.71% (34/56) of patients. V282L was discovered to be the most common variant in heterozygous carriers (45.45%, 15/33). NGS method identified 2 variants that were not determined by the standard method for major mutations detection: p.C170* and p.W22X, accounting for 3% of all known pathogenic variants. Conclusion Our data make it possible to clarify the specific spectrum of CYP21A2 gene pathogenic variants in CAH patients from Surgut. The NGS method allows for the identification of rare pathogenic variants (3%) in the CYP21A2 gene that are not included in the conventional PCR–RFLP analysis

Establishment of a Pilot Newborn Screening Program for Spinal Muscular Atrophy in Saint Petersburg

Spinal muscular atrophy 5q (SMA) is one of the most common neuromuscular inherited diseases and is the most common genetic cause of infant mortality. SMA is associated with homozygous deletion of exon 7 in the SMN1 gene. Recently developed drugs can improve the motor functions of infants with SMA when they are treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using a real-time PCR assay with dried blood spots (DBS) was performed from January 2022 through November 2022 in Saint Petersburg, which is a representative Russian megapolis. Here, 36,140 newborns were screened by the GenomeX real-time PCR-based screening test, and three genotypes were identified: homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns), and wild-type individuals (35,364 newborns). The disease status of all four newborns that screened positive for the homozygous SMN1 deletion was confirmed by alternate methods. Two of the newborns had two copies of SMN2, and two of the newborns had three copies. We determined the incidence of spinal muscular atrophy in Saint Petersburg to be 1 in 9035 and the SMA carrier frequency to be 1 in 47. In conclusion, providing timely information regarding SMN1, confirmation of disease status, and SMN2 copy number as part of the SMA newborn-screening algorithm can significantly improve clinical follow-up, testing of family members, and treatment of patients with SMA