A novel diagnostic strategy for trisomy 21 using short tandem repeats

Abstract

Molecular technique with STRs can rapidly diagnose aneuploidy. In order to improve its fidelity, we developed a novel STR-based strategy for fast diagnosis of trisomy 21 and constructed a multimarker diagnostic system according to it. The system is based on nine STRs, of which two were previously known and seven were newly identified from the genomic sequence of the long arm of chromosome 21. They were confirmed to be highly polymorphic in the Chinese population by PCR amplification and gel electrophoresis. The combination of nine STR markers, when applied to DNA from 102 Chinese individuals with normal karyotype, did not yield any false-positives, and clearly revealed three different alleles in DNA from 15 out of 18 trisomy 21 patients. The results show that our new strategy can provide an alternative molecular technique for the rapid detection of aneuploidy.

A case of an infertile male with a small supernumerary marker chromosome negative for M-FISH and containing only heterochromatin

“…The five STRP markers on chromosome 21 were selected for the copy number analysis with multiplex PCR (the primer sequences are shown in Table 1) [4]. PCR amplification was performed in 25 µL volumes for 30 cycles (PTC-200 peltier thermal cycler, Bio-RAD).…”