Detection of pericentric inversion of X chromosome in a male fetus.
Amniocentesis on a 32-year-old woman at risk for trisomy 21 by maternal serum triple screen showed a 46,Y,inv(X) (p22.1q24) karyotype in all cells analyzed. A blood sample was obtained from the mother for cytogenetic evaluation. Since she had the same inversion, DNA replication studies were performed to determine if the X inactivation pattern was random or not, since skewed inactivation of the inverted X might suggest that the breakpoints disrupted functional genes. DNA replication studies demonstrated that 68% of mother's cells with the inverted X were active, suggesting random X inactivation. The random X inactivation pattern suggested that the inversion is probably balanced and should not affect the fetus. A normal male was delivered at 40 weeks gestation.
Wenger
S L
SL
Department of Pathology, West Virginia University, Morgantown, West Virginia, USA. swenger@hsc.wvu.edu
Cutenese
C
C
Brancazio
L R
LR
D000328:Adult; D000649:Amniocentesis; D007446:Chromosome Inversion; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis; D014960:X Chromosome / Q000235:genetics*