PMC6880252_01
PMC6880252_02
The phenotypic and genotypic characteristics of the adult female patient with unbalanced karyotype 45,XX,der(8;18)t(8;18)(p23;p11.3). (A) The patient's appearance at the age of 31 years. (B) The karyogram of QFH/AcD stained chromosomes from the patient's PHA-stimulated lymphocyte. (C) Metaphase chromosomes from the patient's PHA-stimulated lymphocyte after fluorescence in situ hybridization with DNA probes specific to chromosomes 8 and 18: Vysis CEP 8 (D8Z2) (green), CEP 18 (aqua) (Abbott Molecular), whole chromosome 8 painting probe (orange), whole chromosome 18 painting probe (green) (Applied Spectral Imaging). (D) aCGH results for chromosomes 8 and 18; deleted regions are marked with blue, duplicated regions are marked with red.
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f1
She had a bit shortened arm length, a slight valgus deformity, and disproportionately large feet (Figure 1A). The aberrant chromosome was a product of chromosomes 8 and 18 fusion with apparent loss of their short arm terminal regions (Figure 1B). Morphologically, only the centromere of chromosome 8 formed a constriction, indicating that the aberrant chromosome was a pseudodicentric with one active centromere:that of chromosome 8 (Figure 1C). DNA was extracted from peripheral blood lymphocytes. aCGH revealed a 6.718 Mb deletion in 8p23.1-p23.3, a 3.693 Mb deletion in 18p11.31-p11.32 and, in addition to karyotyping and FISH results, a 4.937 Mb duplication in 8p22 and a 0.060 Mb duplication in 18q23 classified as a copy number variation (CNV) (Figure 1D).
The cytogenetic picture of preimplantation embryos from the patient with unbalanced karyotype 45,XX,der(8;18)t(8;18)(p23;p11.3). The shown chromosome combinations are based on the revealed FISH signal patterns during PGT-SR with DNA probes specific to p and q subtelomeric regions and centromeric regions of chromosomes 8 and 18: TelVysion 8p, TelVysion 18p, TelVysion 8q, TelVysion 18q, Vysis CEP 8 (D8Z2), CEP 18 (Abbott Molecular). In all cases, the inheritance of normal chromosome 8 and normal chromosome 18 from the karyotypically normal farther is assumed. N indicates the number of embryos with detected variant of chromosome combination.
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The most probable chromosome combinations based on the revealed FISH signal patterns are shown on Figure 2. This advocates for a variety of chromosome disjunction patterns with no obvious prevalence of either variant (Figure 2).
Genetic outcomes of the natural pregnancies in the patient with unbalanced karyotype 45,XX,der(8;18)t(8;18)(p23;p11.3). (A) The karyogram of QFH/AcD banded chromosomes from chorionic villi of the miscarriage specimen at 5/6 weeks of gestation, karyotype 45,XX,der(8;18)t(8;18)(p23;p11.3)mat. (B) Summary of non-invasive prenatal testing (NIPT) results in progressing pregnancy at 9/10 weeks of gestation. Z scores for the corresponding chromosomes are present on the y-axis. The dash-lines represent the upper and lower limits of the z score for euploidy. The 18 chromosome score is classified as trisomy. (C) The karyogram of QFH/AcD banded chromosomes from chorionic villi in progressing pregnancy with trisomy 18 detected by NIPT. The karyotype is 46,KHKH,der(8;18)t(8;18)(p23;p11.3)mat,+18.
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An unbalanced karyotype with structurally rearranged chromosome was revealed: 45,KHKH,der(8;18)t(8;18)(p23;p11.3) (Figure 3A). The NIPT of the patient's sample revealed additional material of chromosome 18 (Figure 3B). An abnormal karyotype was detected, as there was only one normal chromosome 8, two normal chromosomes 18, and an aberrant chromosome der(8;18) (Figure 3C).