Prenatal diagnosis of gonosomal anomalies: limitations of the FISH method and genetic counseling difficulties in 15 cases.

UNLABELLED: Prenatal diagnosis (PD) by FISH or cell culture is today an important tool for the prevention of chromosomal anomalies. A difficult issue is prenatal detection of gonosomal anomalies. Most gonosomal anomalies neither affect life expectancy nor cause psychomotor retardation, but sexualization disorders and the lack of reproductive potential are a constant finding. AIM: This study aimed at identifying the medical problems the specialists and the parental couple are faced with at the time of the diagnosis of fetal gonosomal anomalies. MATERIAL AND METHODS: This retrospective study (2004-2012) was conducted in the Prenatal Genetic Diagnosis Department of "CuzaVoda" Maternity by FISH technique in 1685 pregnancies. The AneuVysion probes were used for identifying and enumerating chromosomes 13, 18, 21, X, and Y via fluorescence in situ hybridization (FISH) in interphase nuclei obtained from amniotic fluid. RESULTS: Fifteen fetuses were selected in which we were faced with difficulties interpreting the number of gonosomes: monosomy X (5 cases), pseudomosaicism XX/XY (3), trisomy XXY (3 cases), trisomy XYY (1 case), 45,X/46.XX mosaicism (1 case) and triploidy XXX (2 cases). Later, by repeating the analysis, 2 cases with pseudomosaicism XX/XY were excluded. A case highlighting the limitations of the FISH test was that of a fetus in which the FISH test revealed trisomy XXY, while postnatal karyotyping showed a six cell line mosaicism (marker and ring X chromosomes). CONCLUSIONS: All parental couples received nondirective genetic counseling, respecting the individuals' dignity and rights of self-determination. Parents received information on the natural course of the disease, treatment options, and psychological support and were involved in their child's recovery.