A novel competitive fluorescent multiplex STR polymorphism assay for rapid, reliable and single-tube screening of 22q11.2 copy-number aberrations.
ABSTRACT Copy-number aberrations of the 22q11.2 region can lead to varied resulting and complex phenotypes. Routine screening for these common constitutional chromosomal abnormalities requires powerful tools. A competitive fluorescent multiplex STR polymorphism assay (CFMSA) was built for detecting these aberrations. With the introduction of an internal reference and distinguishable STR polymorphism markers, this competitive fluorescent multiplex STR polymorphism assay provides complementary information about polymorphism and gene dosage in one tube simultaneously, thereby enhancing the assay sensitivity. It was first tested in 110 normal controls, and was proven to have highly polymorphic and reliable gene dosage information. Then, 476 subjects with congenital heart defect were screened according to the testing strategy of the American Heart Association, and 17 deletions and 1 duplication of 22q11.2 were correctly identified. It is expected that this assay will serve as a cost-effective alternative to existing assays for routine, large-scale screening in all at-risk individuals with either deletion or duplication in 22q11.2.
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ABSTRACT: Conotruncal heart defect (CTD) is a complex form of congenital heart disease and usually has a poor prognosis. ZFPM2/FOG2 encodes a transcription cofactor that interacts with GATA4 to regulate cardiac development. This regulation has been established in knockout mouse models that display a range of heart malformations, especially CTD. Although previous studies have identified several missense variants in ZFPM2/FOG2 that may cause CTD, it remains unclear whether they are involved in CTD pathogenesis because the study populations were limited and the functional status was unknown. In this report, we screened a larger CTD population, which comprised 145 tetralogy of Fallot (TOF), 37 double-outlet ventricle outflow (DORV), and 18 transposition of the great artery (TGA), to investigate exon mutations as well as copy number variations in ZFPM2/FOG2. Four variants (p.V339I in one DORV, p.A426T in one DORV, p.M703L in three TOF, p.T843M in one TOF) were found in six patients, of which two are reported here for the first time. No copy number variations of the gene were detected. GST pull-down assays demonstrated that all potentially deleterious variants, including those previously reported, did not impair the interaction with GATA4, except for variant p.M544I and p.K737E, which subtly impaired the binding. Thus, these missense variants may be involved in other mechanisms underlying CTD or may be unrelated to CTD occurrence.PLoS ONE 07/2014; 9(7):e102379. DOI:10.1371/journal.pone.0102379 · 3.53 Impact Factor
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ABSTRACT: One of the most common constitutional chromosomal abnormalities, 22q11.2 microdeletion (del22q11.2) syndrome has diverse medical complications, such as congenital heart defect, hypocalcaemia, and immune deficiency, which require coordinated multidisciplinary care. Until now, the natural history of hypocalcaemia in chromosome del22q11.2 syndrome had been only partly documented, but there has been limited recognition of the importance of calcium status during the postoperative period when altered calcium status may be associated with serious complications. The goals of our study were (1) to delineate the clinical characteristics of serum calcium in patients with del22q11.2 during the postoperative period and (2) to make recommendations for the investigation and management of del22q11.2 patients after cardiac correction. This study included 22 children diagnosed with del22q11.2 syndrome and 110 children without del22q11.2 syndrome from Nanjing Children's Hospital. Clinical examinations and blood ionized calcium testing were reviewed retrospectively. A comparative study of postoperative calcium levels and complications of del22q11.2 patients with nondeletion patients was performed. Association between postoperative hypocalcaemia and adverse incidents after cardiac correction was also examined. Postoperative hypocalcaemia was observed among 86.4% of del22q11.2 patients and among only 47.3% of nondeletion subjects. The difference was statistically significant (P = 0.0017). Patients with del22q11.2 syndrome also had a much sharper decrease in serum calcium levels during the first 6 h after surgery than nondeletion patients. Postoperative clinical analysis showed that del22q11.2 patients with hypocalcaemia experience more postoperative complications (18 of 19) and greater mortality (5 of 19) after cardiac correction than del22q11.2 patients without normal calcium levels and nondeletion patients. Del22q11.2 children have high susceptibility of hypocalcaemia during the postoperative period, and this low calcium status after cardiac correction may be associated with significant risk of postoperative complications and mortality in patients with del22q11.2.Pediatric Cardiology 06/2011; 32(7):904-9. DOI:10.1007/s00246-011-0012-y · 1.55 Impact Factor
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ABSTRACT: People carrying a 22q11.2 microduplication display a phenotype varying from normal to severely affected. We report a phenotypically normal female presented with a fetus having a severe congenital heart defect with ventricular septal defect, tricuspid atresia, patent ductus arteriosus and interrupted aortic arch. The pregnant woman had a history of overall three consecutive aberrant pregnancies with tetralogy of Fallot. Standard G-banding karyotype analysis of the parents and the actual pregnancy were normal, while array comparative genomic hybridization (arrayCGH) analysis revealed a 22q11.2 microduplication within the fetus' genome. Fluorescence in situ hybridization (FISH) and short tandem repeat polymorphism (STRP) tests indicated the affected fetus inherited the interstitial 22q11.2 microduplication from the mother. High-resolution oligonucleotide microarray analysis showed this microduplication is located in the common 3 Mb 22q11.2 deletion region between positions 17.298 Mb and 20.246 Mb with a length of 2.948 Mb. This report demonstrates the remarkable intrafamilial variability of a 22q11.2 microduplication phenotype. The 22q11.2 microduplication carried by one of the healthy parents has most likely contributed to the recurrent fetal heart defects.European journal of medical genetics 04/2011; 54(4):e433-6. DOI:10.1016/j.ejmg.2011.03.009 · 1.49 Impact Factor