RESUMO
OBJECTIVE: To assess the likelihood of finding an etiopathogenic cause in an ultrasonographic prenatal diagnosis of holoprosencephaly. MATERIALS AND METHODS: From January 1996 to June 2010, 13 883 prenatal diagnoses through chorionic villus sampling or amniocentesis were made. Every fetus with holoprosencephaly at ultrasound was evaluated. Gestational age, additional ultrasound findings, and fetal karyotype were recorded. Molecular diagnosis and parental karyotype were studied, if relevant. RESULTS: Twenty-eight fetuses were diagnosed with holoprosencephaly (0.20%). All cases had additional ultrasound findings (100%). A definitive etiology was found in 23 cases (82.14%): karyotype was abnormal in 19 (67.9%) and normal in 8 (28.5%) cases. In the normal karyotype group, although molecular testing was performed in a few cases, one mutation of gene SIX 3 was diagnosed, one diagnosis of dysgnathia complex was made, and two fetuses presented Smith-Lemli-Opitz syndrome. No etiopathogenic diagnosis was made in five fetuses. CONCLUSIONS: Our results showed that a definitive etiology can be established in most cases of prenatal holoprosencephaly. Chromosomal anomalies were the most frequent finding. However, in euploid fetuses, molecular diagnosis is worthwhile, as different genes with different inheritance patterns may be responsible for this malformation. Thorough evaluation proved beneficial for assessing more accurate prognosis and recurrence risks.
Assuntos
Holoprosencefalia/diagnóstico por imagem , Holoprosencefalia/etiologia , Ultrassonografia Pré-Natal , Adulto , Aberrações Cromossômicas , Estudos de Coortes , DNA/análise , Meio Ambiente , Feminino , Aconselhamento Genético , Predisposição Genética para Doença , Idade Gestacional , Holoprosencefalia/genética , Humanos , Cariótipo , Gravidez , Prognóstico , Recidiva , Estudos Retrospectivos , Síndrome de Smith-Lemli-Opitz/genéticaRESUMO
OBJECTIVE: To analyze variables affecting couples' decision making about prenatal cytogenetic diagnosis in patients with no access to legal termination of pregnancy (TOP). METHODS: Patients undergoing invasive prenatal diagnosis were anonymously surveyed after counseling and before the procedure. The questionnaire enquired about sociodemographic features, medical history, knowledge of and attitudes toward genetic testing and TOP. RESULTS: Two genetic units distributed 372 questionnaires. Mean maternal age was 36 +/- 4 years. Access to prenatal genetic counseling was mainly patient's own initiative, or 'self-referral'. Most self-referred patients (87%) considered that 'receiving accurate information' was the main issue. Eighty-one per cent of all couples knew that TOP because of fetal anomalies was not legal. In case of a serious anomaly, 68.2% of patients would contemplate TOP, in spite of the risk of being exposed to an unsafe abortion. CONCLUSIONS: In many countries, prenatal genetic testing is offered, but TOP is not available. In the present study, although most of the couples who decided to undergo prenatal genetic testing were aware of this, they still chose to perform prenatal diagnosis. The main reason given was to obtain reliable information about fetal condition. Finally, if a fetal chromosomal abnormality were detected, most of them would consider TOP.