What causes duplicate 15 xx in newborn with chd?

Question unclear: What is 15 xx and assume you mean congenital heart disease but not sure. Rephrase the question and perhaps it can be responded to more specifically.

Rare with CHD: I assume that you are speaking of chrom 15 duplication syndrome, a very rare problem. Most of the known problems are developmental delay and seizures. Heart disease has been reported (rarely) but there is no specific association with a particular defect.

Unsure: I'm sorry, but i'm not sure of the details. When we refer to a chromosome number, we generally then describe either a p or q (which represent the short and long segments of the chromosome). I have never heard of duplicate 15xx. You can have duplicate 15p or 15q (and this will sometimes be followed by a period with numbers such as 15p.23). Or you can have xo. Please clarify (or educate me!).