Primed In Situ Labeling Technique for Subtelomeric Rearrangements in 70 Children with Idiopathic Mental Retardation / 华中科技大学学报（医学）（英德文版）

Subtelomeric rearrangements contribute to idiopathic mental retardation (MR),but most children with idiopathic MR do not show any chromosome abnormalities with standard cytogenetic analysis.The primed in situ labeling (PRINS) technique,using an oligonucleotide primer complementary to the telemetric repeat sequences (TTAGGG),can identify chromosome telomeric abnormality (deletion) in idiopathic MR children.In this study,seventy children with idiopathic MR were enrolled and subjected to PRINS.The results showed normal karyotype in all the children,subtelomeric rearrangements (1q del and 4q del) in 2 cases,which was confirmed by fluorescence in situ hybridization (FISH).It was concluded that PRINS is effective for the detection of subtelomeric rearrangements and may become a routine technique for cytogenetical abnormality screening.

A De Novo Centric Fission of Chromosome 11 in a Patient with Recurrent Miscarriages

We report on a de novo centric fission of chromosome 11 in a healthy female referred for chromosome analysis due to recurrent miscarriages. Both fission products were mitotically stable. This centric fission of chromosome 11 appears to have no clinical significance for this patient other than recurrent miscarriages.

Rapid Prenatal Diagnosis of Down Syndrome Using Quantitative Fluorescent PCR in Uncultured Amniocytes

Rapid prenatal diagnosis of common chromosome aneuploidies have been successful through quantitative fluoresent PCR (QF-PCR) assays and small tandem repeat (STR) markers. The purpose of our study was to investigate the clinical feasibility for rapid prenatal detection of Down syndrome using the quantitative fluorescent PCR in uncultured amniocytes. DNA was extracted from uncultured amniotic fluid of normal karyotype (n=200) and of Down syndrome (n=21). It was amplified using QF-PCR with four STR markers located on chromosome 21. Among normal samples, the ranges of diallelic peaks for at least one STR marker were 1.0-1.3 for D21S11, 1.0-1.4 for D21S1411 and 1.0-1.5 for D21S1270. Down syndrome samples showed trisomic triallelic patterns or trisomic diallelic patterns. The sensitivity, specificity, and efficiency of the assay for detecting Down syndrome were 95.4%, 100%, and 99.5%, respectively. Rapid prenatal diagnosis of Down syndrome using QF-PCR is a reliable technique that aids clinical management of pregnancy.