BACKGROUND: Chromosomal aneuploidies are a common cause of congenital disorders associated with cognitive impairment and multiple dysmorphic features. Pre-natal diagnosis of aneuploidies is most commonly performed by the karyotyping of fetal cells obtained by amniocentesis or chorionic villus sampling, but this method is labour intensive and requires about 14 days to complete. METHODS: We have developed a PCR based method for the detection of targeted chromosome number abnormalities termed paralogous sequence quantification (PSQ), based on the use of paralogous genes. Paralogous sequences have a high degree of sequence identity, but accumulate nucleotide substitutions in a locus specific manner. These sequence differences, which we term paralogous sequence mismatches (PSMs), can be quantified using pyrosequencing technology, to estimate the relative dosage between different chromosomes. We designed 10 assays for the detection of trisomies of chromosomes 13, 18, and 21 and sex chromosome aneuploidies. RESULTS: We evaluated the performance of this method on 175 DNAs, highly enriched for abnormal samples. A correct and unambiguous diagnosis was given for 119 out of 120 aneuploid samples as well as for all the controls. One sample which gave an intermediate value for the chromosome 13 assays could not be diagnosed. CONCLUSIONS: Our data suggests that PSQ is a robust, easy to interpret, and easy to set up method for the diagnosis of common aneuploidies, and can be performed in less than 48 h, representing a competitive alternative for widespread use in diagnostic laboratories.
BACKGROUND: Chromosomal aneuploidies are a common cause of congenital disorders associated with cognitive impairment and multiple dysmorphic features. Pre-natal diagnosis of aneuploidies is most commonly performed by the karyotyping of fetal cells obtained by amniocentesis or chorionic villus sampling, but this method is labour intensive and requires about 14 days to complete. METHODS: We have developed a PCR based method for the detection of targeted chromosome number abnormalities termed paralogous sequence quantification (PSQ), based on the use of paralogous genes. Paralogous sequences have a high degree of sequence identity, but accumulate nucleotide substitutions in a locus specific manner. These sequence differences, which we term paralogous sequence mismatches (PSMs), can be quantified using pyrosequencing technology, to estimate the relative dosage between different chromosomes. We designed 10 assays for the detection of trisomies of chromosomes 13, 18, and 21 and sex chromosome aneuploidies. RESULTS: We evaluated the performance of this method on 175 DNAs, highly enriched for abnormal samples. A correct and unambiguous diagnosis was given for 119 out of 120 aneuploid samples as well as for all the controls. One sample which gave an intermediate value for the chromosome 13 assays could not be diagnosed. CONCLUSIONS: Our data suggests that PSQ is a robust, easy to interpret, and easy to set up method for the diagnosis of common aneuploidies, and can be performed in less than 48 h, representing a competitive alternative for widespread use in diagnostic laboratories.
Authors: Samuel Deutsch; Alexandra Rideau; Marie-Luce Bochaton-Piallat; Giuseppe Merla; Antoine Geinoz; Giulio Gabbiani; Torsten Schwede; Thomas Matthes; Stylianos E Antonarakis; Photis Beris Journal: Blood Date: 2003-03-20 Impact factor: 22.113
Authors: Ephraim P Hochberg; David B Miklos; Donna Neuberg; Daniel A Eichner; Stephen F McLaughlin; Alex Mattes-Ritz; Edwin P Alyea; Joseph H Antin; Robert J Soiffer; Jerome Ritz Journal: Blood Date: 2002-08-29 Impact factor: 22.113
Authors: Y M Dennis Lo; Fiona M F Lun; K C Allen Chan; Nancy B Y Tsui; Ka C Chong; Tze K Lau; Tak Y Leung; Benny C Y Zee; Charles R Cantor; Rossa W K Chiu Journal: Proc Natl Acad Sci U S A Date: 2007-07-30 Impact factor: 11.205
Authors: C Howald; G Merla; M C Digilio; S Amenta; R Lyle; S Deutsch; U Choudhury; A Bottani; S E Antonarakis; H Fryssira; B Dallapiccola; A Reymond Journal: J Med Genet Date: 2005-07-01 Impact factor: 6.318
Authors: Stefan Taudien; Gabor Gäbel; Oliver Kuss; Marco Groth; Robert Grützmann; Klaus Huse; Alexander Kluttig; Andreas Wolf; Michael Nothnagel; Philip Rosenstiel; Karin Halina Greiser; Karl Werdan; Michael Krawczak; Christian Pilarsky; Matthias Platzer Journal: BMC Res Notes Date: 2012-11-13
Authors: John A L Armour; Raquel Palla; Patrick L J M Zeeuwen; Martin den Heijer; Joost Schalkwijk; Edward J Hollox Journal: Nucleic Acids Res Date: 2006-12-14 Impact factor: 16.971