A 14/14 marker chromosome lymphocyte clone in ataxia telangiectasia.

A lymphocyte clone with a 45, XY karyotype with a 14/14 tandem translocation marker, the frequency of which is time-variable, has been observed in an ataxia telangiectasia patient. Cells with the marker chromotosome were not observed in fibroblasts cultures derived from a skin biopsy, nor was the marker observed in leukocyte cultures from the patient's two affected sibs.