False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13

Table 1

Summary of tissue specific trisomy 13 mosaicism.

Tissue type	# of nuclei with disomy 13	# of nuclei with trisomy 13	# of total nuclei	% of nuclei with trisomy 13
Umbilical cord	21	29	50	58%
Amnion	18	24	42	57%
Intermediate trophoblast	26	46	72	64%
Villous trophoblast	28	13	41	32%
Villous stroma	23	20	43	46%