Genetic Jargon

Yesterday was a day of peace for us.  Dr. Bialer, our Geneticist, called with the results on the "Lee Family genes."  Dr. Bialer was able to confirm that Rachel did in fact have Uni-parental Disomy, paternal, 14 (pat UPD 14).  What does this mean?  It means that Rachel received 2 #14 chromosomes for Ping and none from me.  Research suggests that what initially happens is that a trisomy occurs (2 chromosomes of Ping's and one of mine), the embryo tries to correct itself, but ends up getting rid of the wrong chromosome, thus ending up with both of Ping's and none of mine.  Pat UPD 14 is extremely rare, there are only about a dozen recorded cases in the world.  Most of these cases are translocation or mosaic UPD14.  This means that the broken chromosome has reattached to another chromosome such as #13 or #15.  We know that Rachel did not have translocation or mosaic as her chromosome count was normal.  This makes her case even more rare.  We were told that UPD14 does have a high miscarriage rate. However, Dr. Bialer cannot confirm that this was the cause of my preterm labor.  We have to take into account that her heart muscles were week and her kidneys stopped working.  Why?  We will never know the answer to that.  The good news....the recurrence rate for UPD 14 is extremely low.  Our chances of conceiving another child with this genetic disorder is slim to none.  This statistic doesn't put my heart at ease though.  The rare happened to us, and that makes the rare a reality.