Postnatal Identification of Trisomy 21: An Overview of 7,133 Postnatal Trisomy 21 Cases Identified in a Diagnostic Reference Laboratory in China.

ABSTRACT: This study describes the cytogenetic characteristics of 7,133 trisomy 21 (Tri21) identified from 247,818 consecutive postnatal cases karyotyped in a single reference laboratory in China for a period of 4 years. The average detection rate of Tri21 is 2.88% ranging from 3.39% in 2011 to 2.52% in 2014. The decreased detection rates over the years might reflect a possible impact of noninvasive prenatal testing applied rapidly in China and elective termination of affected pregnancies. 95.32% of the Tri21 karyotypes are standard Tri21, 4.53% are Robertsonian Tri21, and less than 1% are other Tri21 forms. There are more mosaic Tri21 in older children and adults, consistent with previous observations that clinical features in individuals with mosaic Tri21 are generally milder and easily missed dur

SUBMITTER: Zhao W 

PROVIDER: S-EPMC4503670 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature