Cyclopia: An epidemiologic study in a large dataset from the International Clearinghouse of Birth Defects Surveillance and Research
Cyclopia is characterized by the presence of a single eye, with varying degrees of doubling of the intrinsic ocular structures, located in the middle of the face. It is the severest facial expression of the holoprosencephaly (HPE) spectrum. This study describes the prevalence, associated malformations, and maternal characteristics among cases with cyclopia. Data originated in 20 Clearinghouse (ICBDSR) affiliated birth defect surveillance systems, reported according to a single pre-established protocol. A total of 257 infants with cyclopia were identified. Overall prevalence was 1 in 100,000 births (95%CI: 0.89-1.14), with only one program being out of range. Across sites, there was no correlation between cyclopia prevalence and number of births (r = 0.08; P = 0.75) or proportion of elective termination of pregnancy (r = -0.01; P = 0.97). The higher prevalence of cyclopia among older mothers (older than 34) was not statistically significant. The majority of cases were liveborn (122/200; 61%) and females predominated (male/total: 42%). A substantial proportion of cyclopias (31%) were caused by chromosomal anomalies, mainly trisomy 13. Another 31% of the cases of cyclopias were associated with defects not typically related to HPE, with more hydrocephalus, heterotaxia defects, neural tube defects, and preaxial reduction defects than the chromosomal group, suggesting the presence of ciliopathies or other unrecognized syndromes. Cyclopia is a very rare defect without much variability in prevalence by geographic location. The heterogeneous etiology with a high prevalence of chromosomal abnormalities, and female predominance in HPE, were confirmed, but no effect of increased maternal age or association with twinning was observed.
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Available from: Eva Bermejo-Sánchez
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ABSTRACT: The Spanish Collaborative Study of Congenital Malformations (ECEMC) annually undertakes the
preparation and updating of the report of epidemiological surveillance of congenital anomalies in Spain.
ECEMC is a research programme for congenital anomalies, based on an ongoing registry of births in Spain,
which is hospital-based and has a case-control design. It has surveyed about 2.8 million births (Table 1), and gathered data on 41,800 consecutive infants with congenital anomalies and a similar number of healthy controls. Present coverage of the registry is 19.8% of total births in Spain (Table 2). The basal frequency of infants with congenital defects in our country is 2.22% (registered in 1980-1985), and it fell up to 1.07% in 2010, mainly as a result of the impact of elective termination of pregnancy after the detection of foetal anomalies (ETOPFA). ETOPFA has been legal in Spain since the end of the year 1985. Such a statistically significant decrease of the global frequency can be observed (Table 3) in many of the participating hospitals and most Spanish Autonomic Regions (see Fig. 1). Some increases in six hospitals were studied in detail. The only Autonomic Region in which an increase was detected is Extremadura, but this finding is probably due to methodological reasons in the first years, and referrals of high-risk pregnancies to other regions in those years, with considerable further changes that allow a better detection and reporting of cases in this region. The corrected global frequency by hospital and Autonomic Region, taking ETOPFA into account, was also analysed.
The evolution of the frequency of a selected group of 33 defects with a relatively high base frequency
and/or bearing a high morbidity/mortality was studied (Table 4). Most of them diminished along the time,
the only increases being observed for heart/great vessels defects and unilateral renal agenesis, possibly as
a result of better diagnostic procedures. Down syndrome is the defect for which a more marked decrease
was measured (Graphs-1).
A group of 18 defects were selected for the temporal-spatial analyses of the frequency, and also many
statistically significant decreases were observed in most Spanish Autonomic Regions (Tables 5-10). The only increase was detected for anencephaly in the Balearic Islands, based on two births, and no clue on a local cause was obtained. Geographical heterogeneity could be detected in 2010 for anencephaly, spina bifida, anal/rectal atresia/stenosis, and hypospadias. For anencephaly, heterogeneity was attributable to the
previously mentioned relatively high frequency registered in the Balearic Islands. For spina bifida, it was
due to a high frequency observed in La Rioja, but based on the birth of just one case. For anal/rectal
atresia/stenosis it was due to the high frequency registered in the quite distant regions of the Balearic
Islands and La Rioja, and no common factor was identified as a possible cause. In all these cases it is
noticeable that in regions where a small number of births is surveyed, the birth of just one case can bring
the frequency to unusually high levels, and this can generate some geographical heterogeneity. For
hypospadias, it was due to the low frequency observed in 2010 in the Comunidad Valenciana, and the
relatively high frequency registered in Andalucia; all cases were balanic and isolated, and the higher
frequency was observed in three hospitals in the provinces of Córdoba, Jaén and Malaga. All these findings
will be subject to close scrutiny until the next surveillance report.
Due to the importance of immigration in Spain in the last years, the ethnic origin of cases and foreign
extraction of their parents were also analysed. The percentage of foreign parents has significantly increased
with time, and was higher among the cases than among the controls (Graph 4). All ethnic groups had a
higher risk for congenital anomalies than the native white group (Graph 6) and, except the oriental group,
have increased with time (Graph 5).
A reflection is included as a final comment, regarding the need of research on causes of birth defects,
as expressed by Olshan et al. [Am J Med Genet A. 2011;155:1794–1797]: ‘For future generations, it is essential that we identify causes so that effective public health and clinical prevention programs can be established’. ECEMC, and other programmes worldwide, collaborate with that aim. For that purpose, ECEMC has a considerable background and experience of more than 35 years, as well as enough flexibility to adapt itself to new challenges, working for the prevention of birth defects.
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ABSTRACT: The mandatory notification of patients ("cases") with different congenital abnormalities (CAs) diagnosed from birth until the end of the first postnatal year by medical doctors was ordered by the Ministry of Health in Hungary in 1962 and this CA-registry was continued as the Hungarian Congenital Abnormality Registry (HCAR) based on the international recommendation from 1970. The primary objective of the HCAR has been to determine the baseline birth prevalence rate of different CAs as reliably as possible, with three secondary objectives: (i) to detect temporal and/or spatial clusters of CAs; (ii) to evaluate increasing or decreasing time trends of CAs; and (iii) to assist in the planning of medical and social services for children and families affected by CA so that appropriate resources are allocated efficiently and effectively. This paper summarizes the activities and the evolution of the HCAR over the past 50 years (1962-2011) including the Hungarian Case-Control Surveillance of Congenital Abnormalities for postmarketing surveillance of drug teratogenicity and prevention of CAs; the special evaluation of unidentified multiple CAs; the Hungarian Surveillance of Germinal Mutations and several international collaborations. In conclusion, Hungary enjoyed optimal conditions for the HCAR due to a centralized state health system; all deliveries took place in inpatient clinics; the quality of pediatric care was high and pediatricians notified most CAs. Autopsy was mandatory in infant death, the staff of the HCAR did not consider this CA-registry only as a statistical system but the Hungarian Center for Congenital Anomaly Control and the Hungarian Case-Control Surveillance of Congenital Abnormalities based on the HCAR worked with close collaboration with the parents in order to promote the possible good quality of life of their affected children and to prevent their risk of recurrence.
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