XXXX : a review.

@entity154 @entity2007 @entity3152 @entity2650 @entity1757 @entity1692 @entity156 @entity5617 @entity1592 @entity600 @entity169 @entity8882 @entity2241
A review of all prenatal and postnatal diagnoses of trisomy 16 and trisomy 16 mosaicism was carried out in the context of the current understanding of confined placental mosaicism and @entity8882 ( @entity8882 ). The prenatal detection of trisomy 16 cells is associated with a high probability of @entity5617 , @entity3152 , @entity1592 , and @entity2241 . @entity600 were typical of those seen in nonmosaic partial duplications of chromosome 16. Surprisingly, anomalies were sometimes limited to a single organ and included some relatively common @entity154 such as a @entity1757 , @entity2650 , imperforate anus, @entity169 , and clubfoot. The risk for abnormality appeared to be higher in those pregnancies in which trisomy 16 cells were identified in amniotic fluid compared to the detection in chorionic villi samples. Contrary to nonmosaic trisomy 16 with an excess of males, @entity1692 shows an excess of female karyotypes. Following the prenatal detection of trisomy 16 cells, @entity2007 cells are almost never found in fetal or neonatal lymphocytes. Studies on fibroblasts also often fail to confirm the presence of the abnormal cell line even in cases in which @entity156 are present. It is likely that trisomy 16 cells are sometimes present in the early developing embryo even though subsequent cytogenetic studies on fetal or neonatal tissues may not detect any @entity2007 cells. @entity8882 can be excluded as a mechanism for those anomalies that are common to @entity1692 and nonmosaic partial duplications. The term "occult mosaicism" is suggested to describe the situation in which the presence of an abnormal cell line is suspected on the basis of clinical data but unproven by laboratory analysis.
