Pediatric Neurology 49 (2013) 203e204
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Pediatric Neurology
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Clinical Observations
Trisomy 18 and Neural Tube Defects
Rafael Fabiano Machado Rosa PhD a, b, c, *, Patrícia Trevisan MD a, Rosana Cardoso Manique Rosa MD a,
Marina Boff Lorenzen MD d, Paulo Ricardo Gazzola Zen PhD a, d, Ceres Andréia Oliveira MD e,
Carla Graziadio MD a, d, Giorgio Adriano Paskulin PhD a, d
a
Graduate Program in Pathology, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre, RS, Brazil
Clinical Genetics, Hospital Materno Infantil Presidente Vargas (HMIPV), Porto Alegre, RS, Brazil
c
Clinical Genetics, UFCSPA, and Complexo Hospitalar Santa Casa de Porto Alegre, Porto Alegre, RS, Brazil
d
Graduation in Medicine, UFCSPA, Porto Alegre, RS, Brazil
e
Institute of Education and Research, Hospital Moinhos de Vento, Porto Alegre, RS, Brazil
b
article information
abstract
Article history:
Received 22 February 2013
Accepted 24 March 2013
BACKGROUND: Trisomy 18 or Edwards syndrome is a chromosomal abnormality charac-
terized by a broad clinical picture and a limited survival. More than 130 different
abnormalities have been described in these patientsdamong them are neural tube
defects. METHODS: We verified the frequency and types of major neural tube defects
observed among patients with trisomy 18. Our sample consisted of consecutive patients
evaluated by a clinical genetics service of a referral hospital in southern Brazil between
1975 and 2008. Fisher’s exact test (two-tailed) and chi-square test with Yates’ correction
were used to compare frequencies (P < 0.05 values were considered as significant).
RESULTS: During the period of evaluation, we identified 50 patients with trisomy 18; 33
(66%) were female and age at the first evaluation ranged from 1 day to 16 years (median
14 days). One cell line with full trisomy 18 was the predominant cytogenetic finding (90%).
Three patients (6%) had major neural tube defects, all females. These were two patients
(4%) with encephaloceles and one (2%) with myelomeningocele. This last patient undergo
to correction surgery on her first day of life. CONCLUSIONS: Our data, in accordance with the
literature, support the idea that the presence of neural tube defects among patients with
trisomy 18 is not coincidental (i.e., these defects are actually part of the spectrum of
abnormalities presented in trisomy 18). Thus, the diagnosis of trisomy 18 should be
considered in children with major neural tube defects, especially in the presence of other
abnormalities or dysmorphisms.
Ó 2013 Elsevier Inc. All rights reserved.
Introduction
Trisomy 18 or Edwards syndrome is a chromosomal
abnormality characterized by a broad clinical picture and
a limited survival. More than 130 different abnormalities
have been described in these patients, and among them are
neural tube defects [1].
* Communications should be addressed to: Dr. Rosa; Genética Clínica e
UFCSPA/CHSCPA; Rua Sarmento Leite, 245/403; CEP: 90050-170 Porto
Alegre; RS, Brazil.
E-mail address: [email protected]
0887-8994/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.pediatrneurol.2013.03.010
We verified the frequency and types of major neural tube
defects observed among patients with trisomy 18.
Materials and Methods
Our sample consisted of consecutive patients evaluated by a clinical
genetics service of a referral hospital in southern Brazil between 1975
and 2008. The results of cytogenetic analysis and clinical data were
collected from medical records of patients, with emphasis on findings
related to neural tube defects. Fisher’s exact test (two-tailed) and chisquare test with Yates’ correction were used to compare frequencies
(P < 0.05 values were considered as significant). This study was approved
by the Research Ethics Committee of the Universidade Federal de
Ciências da Saúde de Porto Alegre.
204
R.F.M. Rosa et al. / Pediatric Neurology 49 (2013) 203e204
Results
During the period of evaluation, we identified 50
patients with trisomy 18; 33 (66%) were female, and age
at the first evaluation ranged from 1 day to 16 years
(median 14 days). In relation to the cytogenetic findings,
the presence of one cell line with full trisomy 18 was
predominant (90%). Three patients (6%) had major neural
tube defectsdall femalesdthese were two patients (4%)
with encephaloceles and one (2%) with myelomeningocele. The patient with myelomeningocele was one of the
two individuals in the sample who had chromosomal
constitution with double aneuploidy: trisomy 18 associated with triple X. The patient with myelomeningocele
underwent corrective surgery on her first day of life. This
surgical procedure was performed before the diagnosis of
trisomy 18.
have also been described in the literature among individuals
born with trisomy 18 [4].
Conclusion
Our data, in accordance with the literature, support the
idea that the presence of neural tube defects among
patients with trisomy 18 is not coincidental (i.e., these
defects are actually part of the spectrum of abnormalities
presented in trisomy 18). Thus, the diagnosis of trisomy 18
should be considered in children with major neural tube
defects, especially in the presence of other abnormalities or
dysmorphisms. This may have important implications on
the management, prognosis, and genetic counseling of
patients.
We would like to thank Programa de Iniciação Científica-Universidade Federal de
Ciências da Saúde de Porto Alegre and Coordenação de Aperfeiçoamento de Pessoal
de Nível Superior for the scholarships received.
Discussion
Despite central nervous system abnormalities being
common among patients with trisomy 18, neural tube
defects have been considered an uncommon finding [2-4].
Despite this, when we compare the frequency of neural tube
defects found in our sample with that observed in the
general population [5], we observe a significant relationship
(P < 0.0001).
The frequency of neural tube defects found in our sample
(6%) was similar to that described in other studies of trisomy
18 patients (6% to 12%) [2-4]. Myelomeningocele has been
considered the defect most often reported [2-4]. Encephalocele is a rare finding among postnatal patients with
trisomy 18. Interestingly, this defect was the neural tube
defect most observed in our sample. Although not verified in
our study, examples of anencephaly and craniorachischisis
References
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