RecLOH is a term in genetics that is an abbreviation for "Recombinant Loss of Heterozygosity".
Recombination frequency even exceeds the frame shift mutation frequency (slipped strand mispairing) of (average fast) Y-STRs, however many recombination products may lead to infertile germ cells and "daughter out".
Recombination events (RecLOH) can be observed if YSTR databases are searched for twin alleles at 3 or more duplicated markers on the same palindrome (hairpin).
A high proportion of 9-9, 15-15-17-17, 36-36 combinations and similar twin allelic patterns will be found.
PCR typing technologies have been developed (e.g. DYS464X) that are able to verify that there are most frequently really two alleles of each, so we can be sure that there is no gene deletion.