Mosaicism, missing "y" in 15% of cells on amniocentesis at 15wks' & postnatal test. male, now 16. what does this mean?worried grandma.

He's rare: It sounds like you are saying that 85% of his cells are "normal" with 26 chromosomes including 1 x and 1 y (sex chromosomes that make him a boy) but that 15% of his cells have 25, with an x but no y. Is that right? If so, he should be seen regularly by a pediatric endocrinologist. He needs his hormone levels checked and replaced if necessary. Ask the pediatric endocrine doc for more info......

Sounds fine to me: I understand that junior was found to have 15% of cells missing y chromosomes and is now grown into a 16 year old teen with a couple of developmental issues that many other kids share. From my reading, there's no particular syndrome that you're likely to see with this constellation of findings, and everybody's best served by regarding junior as exactly what he is -- a wonderful boy.