High specificity PCR screening for 22q11.2 microdeletion in three different ethnic groups

Abstract

Congenital heart defects are the most common of all human birth defects. Numerous studies have shown that a deletion within chromosome 22q11 is associated with DiGeorge syndrome and certain forms of sporadic congenital cardiovascular disease. We have determined the value of a PCR assay using markers D22S941, D22S944 and D22S264 designed for the screening of 22q11.2 deletion through consecutive homozygosity in an ethnically admixed urban population. The study population comprised 149 unrelated men and women from three different ethnic groups (white, mulatto and black). Test specificity for the overall population was estimated at 98.3%. We found no significant difference when comparing heterozygosity indices and ethnicity (P value = 0.43 (D22S944), 0.22 (D22S264), and 0.58 (D22S941)). There was no significant difference regarding assay specificity between the three different ethnic groups studied. This assay could constitute a cost-effective way to screen a large number of patients at increased risk, since PCR techniques are easily available, are fast, can be automatized, and are significantly less expensive than fluorescence in situ hybridization. Correspondence

Gestational and family risk factors for carriers of congenital heart defects in southern Brazil

“…Despite the fact that CHD are considered the most frequent malformations, little is known about the causes 4,24–28 . The heart is the first organ formed in the embryo, and is vital for the provision of oxygen and nutrients to the fetus for the rest of the gestation 7 .…”

Doença de Graves e deficiência de IgA como manifestações da síndrome de deleção 22q11.2

“…A metodologia adotada para o diagnóstico da deleção 22q11.2 foi o teste PCR utilizando três marcadores altamente polimórficos que abrangem a deleção mais frequente de 3Mb na região crítica envolvida na SD22q11.2, conforme Pereira e cols. (18). Nesse mesmo trabalho, os autores evidenciaram uma especificidade de 98% do exame de PCR em detectar a hetero-zigosidade dos marcadores polimórficos na população geral.…”

Congenital heart disease in Southern Brazil: Potential impact and prevention

“…The frequency described in literature of CHDs considered severe such as those of our sample is 3-4 cases per 1000 live births [6,8]. If we applied this frequency to Rio Grande do Sul in 2005, when according to the Information Service of Live Births (SINASC) there were 147,199 births in the state, we would estimate that it may have occurred at the birth of about 515 patients with CHDs of this type.…”