Trisomy 18 and neural tube defects.
Rafael Fabiano Machado Rosa1, Patrícia Trevisan, Rosana Cardoso Manique Rosa
1Universidade Federal de Ciências da Saúde de Porto Alegre, RS, Brazil. rfmr@terra.com.br
Pediatric Neurology
|July 9, 2013
Summary
Neural tube defects occur in 6% of Edwards syndrome (trisomy 18) patients, including encephaloceles and myelomeningocele. These findings suggest neural tube defects are part of the trisomy 18 spectrum.
Area of Science:
- Genetics
- Developmental Biology
- Clinical Medicine
Background:
- Trisomy 18, or Edwards syndrome, is a chromosomal abnormality with significant clinical impact and limited survival.
- Over 130 distinct abnormalities are associated with trisomy 18, including neural tube defects.
Purpose of the Study:
- To determine the frequency and types of major neural tube defects in patients with trisomy 18.
- To assess if neural tube defects are a coincidental finding or part of the trisomy 18 spectrum.
Main Methods:
- Retrospective analysis of 50 consecutive patients with trisomy 18 evaluated between 1975 and 2008.
- Statistical comparison of frequencies using Fisher's exact test and chi-square test with Yates' correction.
Main Results:
- Three out of 50 patients (6%) with trisomy 18 had major neural tube defects.
- The defects observed were two encephaloceles (4%) and one myelomeningocele (2%), all in female patients.
- The predominant cytogenetic finding was full trisomy 18 in 90% of cases.
Conclusions:
- Neural tube defects are not coincidental in trisomy 18 but are part of its spectrum of abnormalities.
- The diagnosis of trisomy 18 should be considered in infants with major neural tube defects, particularly if other anomalies are present.
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