Abstract
To the Editor: I read with interest the letter by Vekemans et al.1 on chromosomal mosaicism on amniocentesis as a possible indication for fetoscopy. It is misleading to imply that fetoscopy can confirm "pseudomosaicism." According to the criteria of Boué et al.,2 it is the finding of a similar chromosomal abnormality in a minimum of two independently cultured vessels that defines true chromosomal mosaicism.In true chromosomal mosaicism it has been repeatedly demonstrated that the degree of chromosomal mosaicism varies from one tissue to another. In a case of trisomy 8 mosaicism,3 trisomy 8 was found in 10 per cent . . .