title: Molecular screening for 22Q11.2 deletion syndrome in patients with congenital heart disease.
abstract: Few studies have investigated the prevalence of 22q11.2 deletion syndrome (22q11.2DS) among patients with isolated heart defects or nonconotruncal heart defects. Polymerase chain reaction (PCR) followed by length polymorphism restriction fragment analysis (RFLP) is useful for low-cost molecular diagnosis and screening. This cross-sectional study included 392 patients with congenital heart disease, described clinical features, and performed PCR-RFLP for analysis of polymorphism in three loci with a high heterozygosity rate located in the typically deleted region of 1.5 megabases. Heterozygosity excluded 22q11.2DS. Patients with homozygosity for the three markers underwent multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) for the final diagnosis, estimating the prevalence of 22q11.2DS. The use of PCR-RFLP excluded 22q11.2DS in 81.6 % (n = 320) of 392 patients. Of the remaining 72 patients, 65 underwent MLPA, showing 22q11.2DS in five cases (prevalence, 1.27 %). Four of these five patients underwent FISH, confirming the MLPA results. All five patients with the deletion had heart diseases commonly found with 22q11.2DS (interrupted aortic arch, persistent truncus arteriosus, tetralogy of Fallot, and ventricular septal defect plus atrial septal defect). Two patients had congenital extracardiac anomaly (one with arched palate and micrognathia and one with hypertelorism). Three patients reported recurrent respiratory infections, and one patient reported hypocalcemia. All were underweight or short in stature for their age. This study contributed to showing the prevalence of 22q11.2DS in patients with any congenital heart disease, with or without other features of the syndrome. Patients with 22q11.2DS may not have all the major features of the syndrome, and those that are found may be due to the heart defect.
authors.affiliation: Unidade de Pesquisa, Instituto de Cardiologia/Fundação Universitária de Cardiologia, Avenida Princesa Isabel, 370, Santana, Porto Alegre, RS, 90620-000, Brazil.
authors.forename: Janaína
authors.initials: J
authors.lastname: Huber
authors.forename: Vivian Catarino
authors.initials: VC
authors.lastname: Peres
authors.forename: Alexandre Luz
authors.initials: AL
authors.lastname: de Castro
authors.forename: Tiago Jeronimo
authors.initials: TJ
authors.lastname: dos Santos
authors.forename: Lauro
authors.initials: L
authors.lastname: da Fontoura Beltrão
authors.forename: Angélica Cerveira
authors.initials: AC
authors.lastname: de Baumont
authors.forename: Silvia Liliana
authors.initials: SL
authors.lastname: Cossio
authors.forename: Tiago Pires
authors.initials: TP
authors.lastname: Dalberto
authors.forename: Mariluce
authors.initials: M
authors.lastname: Riegel
authors.forename: Andrés Delgado
authors.initials: AD
authors.lastname: Cañedo
authors.forename: Beatriz D'Agord
authors.initials: BD
authors.lastname: Schaan
authors.forename: Lucia Campos
authors.initials: LC
authors.lastname: Pellanda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D003430:Cross-Sectional Studies; D004062:DiGeorge Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D055815:Young Adult