| Summary: | Fertility disorders affect numerous individuals, with an estimated 10-20% of couples worldwide experiencing difficulties in conceiving. In this context, genetic factors and chromosomal abnormalities stand out as one of the main causes, given that 1 in every 500 live newborns has chromosomopathies, 1 in every 1000, 1 in every 1000 individuals carries some balanced translocation, and at least 50% of spontaneous abortions are attributed to chromosomal abnormalities. Furthermore, couples who present reproductive difficulties, recurrent miscarriages, fetal deaths, or prior children with malformations have a high incidence of chromosomal alterations and chromosomal heteromorphisms, which suggests a significant association. In our study, which covered the period 2011-2021, peripheral blood samples were collected from patients with reproductive problems from the Dr. Ramón Madariaga Hospital and other healthcare institutions in the province of Misiones. Cell processing and culture were performed to obtain lymphocyte metaphases, and banding techniques like GTG, CBG, and NOR were employed to establish the karyotype and identify chromosomal abnormalities and heteromorphisms. The cytogenetic results from a total of 652 samples revealed 54% women (352 cases) and 46% men (300 cases), with 78% having normal karyotypes (509 cases), 22% showing some chromosomal abnormality (143 cases), 49% of chromosomal heteromorphisms (70 cases), 16% of numerical chromosomal alterations (23 cases), 20% of structural chromosomal alterations (28 cases), 14% of chromosomal mosaicisms (20 cases), and 1% of other variants (2 cases). Among the most common chromosomal abnormalities were X monosomy, XXY trisomy, XYY trisomy, and mosaicism involving the sex chromosomes. Regarding structural chromosomal abnormalities, the presence of inversions in chromosomes 9 and 13, isochromosomes of the long arm of the X chromosome, reciprocal and Robertsonian autosomal translocations, rings, and marker chromosomes were detected. Meanwhile, observed chromosomal heteromorphisms included increases or decreases in heterochromatic regions (1qh, 9qh, 16qh, Yqh) and increases, decreases, or tandem duplications in satellite regions of acrocentric chromosomes (13, 14, 15, 21, and 22). Finally, only two cases of women with a 46,XY karyotype were detected, corresponding to gonadal dysgenesis, disorders of sexual differentiation or Swyer syndrome. Despite the availability of molecular diagnostic tools, karyotype establishment remains the first line of detection for chromosomal alterations and heteromorphisms. This approach enables the identification of chromosomal abnormalities, genotype-phenotype correlations and prognosis, all essential for providing rational, precise and efficient care to every patient and couple looking to plan their family.
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33-Year Contribution of the Cytogenetics and Human Genetics Laboratory (LACyGH) – UNaM – IPS Agreement