A PCR based X-chromosome inactivation assay for carrier detection in X-linked immunodeficiencies using differential methylation of the androgen receptor gene.
Carrier detection in X-linked immunodeficiencies (X-SCID, WAS, XLA) relies on the demonstration of non-random X inactivation patterns in blood cell lineages. Only a limited number of cells are available after cell separation methods. PCR-based techniques are therefore necessary to analyze active and inactive X chromosomes. Amplifying a polymorphic CAG repeat in the first exon of the androgen receptor gene after selective digestion of the active X chromosome with a methylation-sensitive restriction enzyme allows to distinguish between the paternal and maternal alleles and to identify their methylation status. DNA from B-, T-lymphocytes and total peripheral leukocytes of normal males, females and obligate carriers of X-linked immunodeficiencies were analyzed. The results of this PCR-based X inactivation assay are concordant with the standard methylation studies at the DXS255 locus using Southern blotting. This PCR assay provides a rapid and informative (heterozygosity > 90%) method in carrier detection of X-linked immunodeficiencies and other X-linked disorders, which show non-random X inactivation in cell lineages from the affected tissues.
Schmucker
B
B
Institut für Humangenetik, Universität Erlangen, Germany.
Meindl
A
A
Achatz
H
H
Mittermüller
J
J
Krüger
G
G
Hergersberg
M
M
Spiegel
R
R
Schinzel
A
A
Belohradsky
B H
BH
Murken
J
J
D004247:DNA / Q000032:analysis; D004303:Dosage Compensation, Genetic; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods*; D008040:Genetic Linkage / Q000235:genetics*; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics*; D008297:Male; D008745:Methylation; D016133:Polymerase Chain Reaction / Q000379:methods*; D011944:Receptors, Androgen / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*
D011944:Receptors, Androgen; D004247:DNA