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C Escallon

Publications and source records attributed to C Escallon.

4 recordsLinked to original sources
PubMed1998

Region-specific FISH probes used to identify and characterize an interstitial paracentric inv(21)(q22.1q22.3).

Region-specific probes developed for the diagnosis of specific syndrome, can be adapted to elucidate the exact nature of certain chromosomal structural anomalies. We describe the use of FISH probes in characterizing a prenatally diagnosed chromosome rearrangement. An abnormal chromosome 21 was detected during amniocentesis for maternal age indication, and a similar appearing chromosome 21 was found in the mother. The exact nature of the rearrangement was not immediately evident from G-banded karyotypes. FISH was performed using a whole chromosome painting probe, as well as the region-specific probes D21S65 (21q21-22.1), D21S55 (21q22.3) and D21S1219/D21S1220 (21q22.3-qter) (Oncor). Results showed an interstitial paracentric inversion, with breakpoints in bands 21q22.1 and 21q22.3, which was identical in the mother and the fetus: 46,XX,?inv(21)(q).ish inv(21)(q22.1q22.3)(wcp+.D21S65 mv, D21S55 mv, D21S1219/D21S1220 st). In this case, FISH using region-specific probes was helpful in characterizing the inversion and aided in the genetic counselling of risk assessment for the family.

Adult↗
PubMed1995

An accessory marker derived from chromosome 20 and its co-existence with a mosaic trisomy 20 cell line.

We report a 16-month-old boy with delayed psychomotor development, dysmorphic features, and failure to thrive. He had a mosaic karyotype detected prenatally: mos 46,XY/47,XY, +r(20)/47,XY, +20. After birth, the abnormal cell lines were confirmed in a number of tissues. The small ring chromosome was identified using fluorescence in situ hybridization as derived from chromosome 20. We compared our patient with previously reported cases of mosaic trisomy 20 detected prenatally and associated with an abnormal phenotype. In an attempt to characterize an r(20) syndrome, we also compared our case with two similar reports in the literature.

Cell Line↗
PubMed1992

Chorionic villus sampling for fetal Rh typing: clinical implications.

OBJECTIVE: The prenatal Rh typing of red blood cells obtained by chorionic villus sampling was performed with an immune rosette technique. STUDY DESIGN: Ten Rh-negative pregnant women undergoing chorionic villus sampling at 9 to 11 weeks' gestation were studied at a large referral hospital. RESULTS: Accurate Rh phenotyping may be done on red blood cells obtained from chorionic villi weighing 2 to 8 mg. The preparations were shown to be greater than 90% fetal in origin as demonstrated by radial immunodiffusion quantitation of fetal hemoglobin-containing cells. Of the 10 fetuses typed in the first trimester nine of the pregnancies were carried to term. In all cases typing of red blood cells confirmed the antenatal fetal red cell typing. CONCLUSIONS: This study shows that antenatal Rh phenotyping may be performed as early as 9 to 11 weeks' gestation. This technique may be used in the management of pregnancies complicated by Rh incompatibility.

Blood Grouping and Crossmatching↗