I have a child with nf, she's spontanous, not me or my hubby have it, so if i do a cvs can we know if second child has nf too?

Neurofibromatosis : Type I (NF1) is caused by mutation in the neurofibromin gene on chromosome 17q11.2. A Chromosome Microarray Analysis done on CVS or Amniocentesis can detect it prenatally. Your OB, perinatologist or fetal-maternal medicine specialist will have to obtain a prior authorization for the lab to do a CMA rather than standard Chromosome Analysis. See http://www.ctf.org.

Neurofibromatosis: Yes. Prenatal testing with amniocentesis or chorionic villus sampling can detect Neurofibromatosis Type 1. NF-1 occurs as a gene mutation on chromosome 17. Half the cases are inherited as autosomal dominant and half of the cases can be spontaneous.

I'd advise it: One of you may be a mosaic and have many germ cells affected.