CORRELACIÓN FENOTIPO-CARIOTIPO Y DETERMINACIÓN DEL RIESGO REPRODUCTIVO EN MUJERES CON MOSAICISMO DEL CROMOSOMA “X”

Abstract

Is calculated a frequency of 11% of cytogenetic abnormalities in patients with reproductive problems, in which are included the sexual chromosomal mosaics. In women this alterations with 2 or 3 cellular lines: 45, X/46, XX or 45, X/46, XX/47, XXX enrolled with physic phenotypes and variable reproductive, also the cellular lines 46,XX/47,XXX; 46,XX/47,XXX/48,XXXX or 47,XXX/48,XXXX that had not been correctly studied until this moment. All this variants can be named as Mosaics from the “X” chromosome. This one has been reported by some authors with abnormal sexual development, pregnancy loses, newborns with chromosomal diseases or sons with congenital defects. The objective of this research was to know in a sample of Mexican women the chromosome “X” mosaic frequency and correlation it with other reproductive alterations. At the same time was considered: 1) Determine which is the main cause for query in chromosome “X” mosaics. 2) Know which is the most frequent chromosome “X” mosaic. 3) Establish the correlation of GTG bands with FISH. 4) Discard the presence of “Y” chromosome by FISH. 5) Establish the phenotype-karyotype correlation in each case. 6) Establish a flowchart research for these patients. The couples with reproductive alterations who went to query in Genetics from the Instituto Nacional de Perinatología were attended, making their clinic genetic history, their family tree and physical examination having as selection criteria: 1) Primary or secondary amenorrhea. 2) Primary or secondary sterility. 3) Recurrent pregnancy loss. 4) Previous son(s) with congenital defects. 5) Previous son(s) with chromosomal disease. 6) Premature ovarian failure. The karyotype in peripheral blood with GTG Bands (with Trypsin and Giemsa) had been made in couples with the requirements, with the Moorhead modified technique, for numerical and structural analysis with a 450 band resolution. We analized 100 metaphase by GTG bands and 500 interfase cells by FISH (Fluorescence in situ hybridization) with cen X/cen Y probe, for patient. 87 women with the mosaic detected got into the research protocol, between 19 and 44 years old, finding as the most frequent causes for query: 1) Recurrent abortion(56). 2) Amenorrhea (12). 3) Sterility (7). 4) Son with pregnancy defects (7) and 5) Abortion and son(s) with pregnancy defects, finding that the most frequent chromosome “X” mosaic was: 45,X/46,XX/47,XXX(37); 45,X/46,XX(29) and 46,XX/47,XXX(19); 45,X/46,XX/47,XXX/48;XXXX(1) and 46,XX/47,XXX/48,XXXX(1). Sequences in the chromosome Y were not found in any of the analyzed samples. The results were given to the patients and under informed consent the integral protocol of research started. An evaluation from cardiology, ophthalmology, stomatology and psychology was made to the patients, as the making of a hormonal profile, pelvic and renal ultrasound and in case of being necessary an excretory urography and a hysterosalpingography. The results were: 1) This alteration has not been integrally studied, 2) The most frequent cause of query is the recurrent abort, 3) The mosaic with most appearance is 45,X/46,XX/47,XXX, 4) Sequences of Y were not found, 5) These women could present phenotypic alterations in a reproductive level, 6) The risk for the offspring is variable, 7) Is important the entry to a multidisciplinary and interdisciplinary research protocol of these patients, 8) In case of posterior pregnancy is of great importance the follow until its resolution, also the making of pregnancy diagnosis studies and follow of the newborn. In addition is proposed a flow scheme for the patients’ attention.