Monitoring of hematopoietic chimerism by short tandem repeats, and the effect of CD selection on its sensitivity.

shared by subfamily members. The family described here is the second reported in which insertion of an Alu has caused BCHE deficiency; the first was described by Muratani et al. (8 ). Although the Alu sequence in the present study was classified as AluYb8 because of similarities with the AluYb8 reported by Muratani et al. (8 ), it also differed at several nucleotides. In the present study, if genetic analysis had been performed only on the proband, he would have been misdiagnosed as homozygous for the G365R mutation. Analysis of the family revealed a discrepancy in genotype segregation, which directed us to additional analyses and allowed us to reach the proper conclusion. Shorter PCR programs are convenient for mutation detection, but fragments that are longer than expected may not be amplified and would therefore be missed. We conclude from our present experience that PCR with short extension times may be a source of pitfalls in mutation detection.