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I Ribas

Publications and source records attributed to I Ribas.

4 recordsLinked to original sources
PubMed2002

Prenatal and postnatal characterization of Y chromosome structural anomalies by molecular cytogenetic analysis.

We describe three cases in which we used fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) and comparative genomic hybridization (CGH) to characterize Y chromosome structural anomalies, unidentifiable by conventional G-banding. Case 1 was a 46,X,+mar karyotype; FISH analysis revealed an entire marker chromosome highlighted after hybridization with the Y chromosome painting probe. The PCR study showed the presence of Y chromosome markers AMG and SY620 and the absence of SY143, SY254 and SY147. CGH results confirmed the loss of Yq11.2-qter. These results indicated the presence of a deletion: del(Y)(q11.2). Case 2 was a 45,X [14]/46,XY[86] karyotype with a very small Y chromosome. The PCR study showed the presence of Y chromosome markers SY620 and AMG, and the absence of SY143, SY254 and SY147. CGH results showed gain of Yq11.2-pter and loss of Yq11.2-q12. These results show the presence of a Yp isodicentric: idic(Y)(q11.2). Case 3 was a 45,X,inv(9)(p11q12)[30]/46,X,idic(Y)(p11.3?),inv(9)(p11q12)[70] karyotype. The FISH signal covered all the abnormal Y chromosome using a Y chromosome paint. The PCR study showed the presence of Y chromosome markers AMG, SY620, SY143, SY254 and SY147. CGH only showed gain of Yq11.2-qter. These results support the presence of an unbalanced (Y;Y) translocation. Our results show that the combined use of molecular and classical cytogenetic methods in clinical diagnosis may allow a better delineation of the chromosome regions implicated in specific clinical disorders.

Adolescent↗
PubMed2001

Identification of two de novo partial trisomies by comparative genomic hybridization.

We report the use of comparative genomic hybridization (CGH) to define the extra chromosome region present in two de novo partial trisomies 15q25-qter and Xp21-pter, which could not be clarified by conventional G-banding. Investigation with fluorescence in situ hybridization (FISH) revealed that the partial trisomy corresponded to an unbalanced translocation between Y and 15 chromosomes in 1 patient and an unbalanced X/X reorganization in the other patient. The combination of classical karyotyping, CGH, and FISH is useful for the identification and characterization of partial trisomies in clinical diagnostic laboratories, in order to delineate the chromosome regions implicated in specific clinical disorders.

Child↗
PubMed1997

Early detection of reversed diastolic umbilical flow: should we offer karyotyping?

In normal pregnancy, end-diastolic flow appears in the umbilical artery around the 13th week of gestation, with a velocity which increases progressively with advancing gestation. The detection of reversed flow in the umbilical artery, the highest expression of an increase in placental vascular resistance, is extremely uncommon in the first half of gestation and, in three of the four cases reported in the literature, there were chromosomal abnormalities. We report a new case of reversed end-diastolic flow in the umbilical artery in a 13-week fetus with increased nuchal translucency thickness, megacystis and tachycardia. Cytogenetic analysis of chorionic villi and amniocytes revealed trisomy 13. The findings provide further evidence for a possible association between reversed end-diastolic flow in the umbilical artery and chromosomal abnormalities. However, the effectiveness of this potential marker in an unselected population requires further evaluation.

Adult↗