Direct karyotyping of unstimulated newborn blood: a rapid diagnostic method for the clinical management of critically ill newborns.
Using spontaneously dividing nucleated erythrocytes present in newborn cord and peripheral blood, we performed direct karyotype analysis on a cohort of 162 infants suspected of chromosome abnormalities. A cytogenetic diagnosis was obtained in 149 cases (91.9%). In all cases conventional phytohaemagglutinin- (PHA)-stimulated cultures were used for comparison. Concordance between direct and stimulated karyotypes was seen in all but 5 cases. In these 5 cases, abnormalities were seen in the direct harvest while PHA-stimulated cultures showed normal results. Skin fibroblasts from 2 of these cases, available for follow-up, showed the abnormalities in a mosaic state. Our experience confirms that direct karyotyping of fetal and newborn blood is feasible, fast, and efficient and can provide accurate diagnosis of major chromosome abnormalities within 18-24 hours after obtaining the blood.
Tharapel
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SA
Department of Pediatrics, University of Tennessee, Memphis 38163, USA.
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D002869:Chromosome Aberrations; D015331:Cohort Studies; D003422:Critical Care; D005312:Fetal Blood; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping / Q000379:methods*; D008677:Metaphase; D011446:Prospective Studies