CARRIER DETERMINATION FOR X-LINKED AGAMMAGLOBULINEMIA USING X-INACTIVATION ANALYSIS OF PURIFIED B-CELLS

We report the development of a relatively quick and simple method for the assessment of X inactivation status for carrier determination in f amilies affected by X-linked agammaglobulinemia (XLA). This method uti lises an immunomagnetic separation technique for B cell purification a nd a polymerase chain reaction (PCR) based assay for the determination of methylation status at the androgen receptor (AR) gene locus to ass ess whether X inactivation is random or non-random at this locus. We r eport the results we have obtained using this assay to investigate fem ales known to be carriers of various X-linked immunodeficiency disorde rs. In addition, we investigated four females from different families affected by XLA, two of whom were of unknown carrier status, and we di scuss the results obtained with this and other X-inactivation assays. A similar assay has recently been described by Allen et al. (1992) and applied to members of one family affected by XLA.