Copy number variation in Williams-Beuren syndrome: suitable diagnostic strategy for developing countries.

BACKGROUND: Williams-Beuren syndrome (WBS; OMIM 194050) is caused by a hemizygous contiguous gene microdeletion at 7q11.23. Supravalvular aortic stenosis (SVAS), mental retardation, and overfriendliness comprise typical symptoms of WBS. Although fluorescence in situ hybridization (FISH) is considered the gold standard technique, the microsatellite DNA markers and multiplex ligation-dependent probe amplification (MLPA) could be used for to confirm the diagnosis of WBS. RESULTS: We have evaluated a total cohort of 88 patients with a suspicion clinical diagnosis of WBS using a collection of five markers (D7S1870, D7S489, D7S613, D7S2476, and D7S489_A) and a commercial MLPA kit (P029). The microdeletion was present in 64 (72.7%) patients and absent in 24 (27.3%) patients. The parental origin of deletion was maternal in 36 of 64 patients (56.3%) paternal in 28 of 64 patients (43.7%). The deletion size was 1.55 Mb in 57 of 64 patients (89.1%) and 1.84 Mb in 7 of 64 patients (10.9%). The results were concordant using both techniques, except for four patients whose microsatellite markers were uninformative. There were no clinical differences in relation to either the size or parental origin of the deletion. CONCLUSION: MLPA was considered a faster and more economical method in a single assay, whereas the microsatellite markers could determine both the size and parental origin of the deletion in WBS. The microsatellite marker and MLPA techniques are effective in deletion detection in WBS, and both methods provide a useful diagnostic strategy mainly for developing countries.

Increased levels of air pollution and a decrease in the human and mouse male-to-female ratio in São Paulo, Brazil.

A significant negative association (R(2) = 0.7642; P=.013) between particulate matter and secondary sex ratio was found when evaluating people in the city of São Paulo, Brazil. An animal model with male mice raised in nonfiltered open-top chambers showed a significant reduction in the secondary sex ratio (P=.041), suggesting that ambient air pollution may interfere with sex distribution by altering the X:Y sperm proportion in pollution-exposed males.

Amostra de vilo corial: 1290 casos / Chorionic villus sampling: 1290 cases

Os autores estudaram 1.290 gestantes que se submeteram ao diagnóstico pré-natal precoce (primeiro trimestre de gestaçao) para detectar possíveis anormalidades cromossômicas no feto.O método utilizado foi a amostra de vilo corial coletada por via transcervical (AVC-TC) ou por via transabdominal (AVC-TA), dependendo das condiçoes anatômicas e da idade gestacional das pacientes. Entre as gestantes estudadas, 68,5 por cento tinham como principal indicaçao para o exame a idade avançada (igual ou superior a 35 anos); seguida de ansiedade, 11,24 por cento; filho anterior com outras anomalias cromossômicas, 10,2 por cento; filho anterior malformado, 2,9 por cento; rearranjo cromossômico nos pais, 2,6 por cento; determinaçao de sexo (nos casos de doenças ligadas ao cromossomo X), 2,5 por cento; outras indicaçoes, 2,2 por cento. Sao discutidos, neste trabalho, a importância da realizaçao da amostra de vilo corial (AVC) no primeiro trimestre da gestaçao para o diagnóstico pré-natal de alteraçoes cromossômicas no feto.