We analyzed Spanish Collaborative Study of Congenital Malformations (ECEMC) data on a series of 1,124,654 consecutive births to study congenital eye malformations from an epidemiological standpoint. We studied their frequencies as well as some causal and clinical aspects. Four hundred fourteen infants had eye malformations, for an overall prevalence of 3.68/10,000 newborns. Most frequent were: anophthalmia/microphthalmia (21.34/100,000), congenital cataract (6.31), coloboma (4.89), corneal opacity (3.11), and congenital glaucoma (2.85). In our data, the tendency of eye malformations to be associated with other congenital abnormalities is evident (only 21.01% of cases were isolated). Eye defects are heterogeneous, since we have observed them in clinical patterns with all modes of inheritance or caused by different environmental agents. Chromosomal syndromes represent 60% of total syndromes, followed by syndromes of autosomal-recessive inheritance (15%), environmental syndromes (10%), autosomal-dominant syndromes (5.83%), and other types which have a lower frequency. Regarding defects associated with eye malformations, most frequent are limb anomalies (affecting 59.3% of multiply malformed cases), auricular/facial (47.1%), central nervous system (42.5%), osteomuscular excluding limbs (42.2%), genital defects (30.6%), oral clefts (29.4%), and the rest of the body systems, which are less frequent. Using the method outlined by Prieto and Martínez-Frías [1996: Am J Med Genet 62:61-67], it was demonstrated that the association of coloboma and anophthalmia/microphthalmia was specific, as was the combination of cataract and anophthalmia/microphthalmia, and that of anophthalmia/microphthalmia with holoprosencephaly. From these statistical associations some pathogenetic relationships in human embryos can be inferred, supporting several previously proposed mechanisms.

Exstrophy of the bladder (EB) and exstrophy of the cloaca (EC) are generally recognizable as distinct clinical entities. In patients with EB, the posterior bladder wall is exposed through a midline defect of the abdomen. The umbilicus is inferiorly displaced and located close to the superior margin of the exstrophic bladder. Genital abnormalities are common in boys and girls who may present epispadias and a small, split phallus or a split clitoris, a bifid uterus, and a duplicate or exstrophic vagina. In contrast to classic EB, EC is commonly associated with omphalocele, spinal defects, and incompletely formed external genitalia and is always associated with imperforate anus. Some authors state that EC and EB constitute two distinct disorders, but others consider them part of a "continuum," representing different levels of severity within the same spectrum. The use of the acronym OEIS to refer to the combination of omphalocele, exstrophy, imperforate anus, and spinal defects, in our opinion, has not helped to clarify the clinical definition, pathogenesis, or cause of this multiple congenital anomaly (MCA) pattern, mostly because the term makes no distinction between EC or EB. Here we present the epidemiological analysis of a group of characteristics in infants with EC and infants with EB to determine if they constitute two different entities. We also analyze if the different combinations of omphalocele, imperforate anus, and spinal defects are more frequent in infants with EC than in infants with MCA patterns other than EC and EB. The prevalence in our data for EC was 1:200,233 live births and 1:35,597 for EB. The clinical analysis indicated that the study defects (omphalocele, spine defects, spina bifida, and imperforate anus) tend to occur together in the same child with a higher frequency if the child has the EC defect than in infants with MCA patterns that did not include EC or EB. Our findings of low birth weight, twinning, single umbilical artery, and preferentially associated malformations suggest that EC is the result of damage occurring very early in development and that EC and EB are two different expressions of a primary polytopic developmental field defect.

BACKGROUND: EUROCAT is a network of population-based congenital anomaly registries providing standardized epidemiologic information on congenital anomalies in Europe. There are three types of EUROCAT membership: full, associate, or affiliate. Full member registries send individual records of all congenital anomalies covered by their region. Associate members transmit aggregate case counts for each EUROCAT anomaly subgroup by year and by type of birth. This article describes the organization and activities of each of the current 29 full member and 6 associate member registries of EUROCAT. METHODS: Each registry description provides information on the history and funding of the registry, population coverage including any changes in coverage over time, sources for ascertaining cases of congenital anomalies, and upper age limit for registering cases of congenital anomalies. It also details the legal requirements relating to termination of pregnancy for fetal anomalies, the definition of stillbirths and fetal deaths, and the prenatal screening policy within the registry. Information on availability of exposure information and denominators is provided. The registry description describes how each registry conforms to the laws and guidelines regarding ethics, consent, and confidentiality issues within their own jurisdiction. Finally, information on electronic and web-based data capture, recent registry activities, and publications relating to congenital anomalies, along with the contact details of the registry leader, are provided. CONCLUSIONS: The registry description gives a detailed account of the organizational and operational aspects of each registry and is an invaluable resource that aids interpretation and evaluation of registry prevalence data. Birth Defects Research (Part A) 91:S51-S100, 2011. Ó 2011 Wiley-Liss, Inc.Key words: congenital anomaly registries; population-based; ascertainment; organization; Europe AUSTRIA, STYRIA -FULL MEMBER History and FundingThe registry was set up in 1986 after the Chernobyl disaster. It registers fetuses/babies with congenital anomalies born after January 1, 1985. The registry has been a member of EUROCAT since 1995. It is funded by research grants provided by the Styrian Government on an annual basis. Population CoverageThe registry covers all births to residents of the province of Styria (population-based I 5 all mothers resident in defined geographic area), which amounts to a total of approximately 10,000 births annually. See Table 1 for coverage of European birth populations. Sources of AscertainmentPediatric cardiology centers supply systematic case lists and diagnostic details to the registry.There is one central cytogenetic laboratory in Styria that covers the whole population and provides a list of all abnormal prenatal and neonatal karyotypes annually. The registry has no direct electronic link to cytogenetics, but has close contact almost every day. So the local cytogenetic database can be used easily, although indirectly.The registry operates as a research program w...

The association between maternal diabetes mellitus and congenital defects has been well documented. However, few data exist on the potential teratogenic effect of gestational diabetes (GD). We analyzed 19,577 consecutive infants with malformations of unknown cause and compared the offspring of mothers with GD with those of nondiabetic mothers. The children with each of 20 types of selected anomalies among the two groups were used to calculate the odds ratio (OR). Because we used as a reference group for each congenital defect the rest of malformed infants, the value of the OR gives us the specificity between the association of GD and each congenital defect. Our analysis strongly supports the suggestion that GD is a significant risk for holoprosencephaly, upper/lower spine/rib, and renal and urinary system anomalies. GD is a heterogeneous disorder, which includes previously unrecognized and newly diagnosed nongestational diabetes mellitus (DM). Thus, it is possible that the teratogenic effect is related to latent DM. However, because it is not possible at this time to differentiate between these situations, pregnancies complicated by GD should be considered at risk for congenital anomalies. Prenatal ultrasound examination should be aimed particularly at the detection of abnormalities of the central nervous system, the renal and urinary system, and the spine/rib developmental field.

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This study was aimed at analyzing the effect of mutations in three non-synonymous SNP genes (677C > T and 1298A > C of the methylenetetrahydrofolate reductase (MTHFR) gene, and 66A > G in the MTRR gene) on total plasmatic homocysteine (Hcy), in 91 mothers of Down syndrome (DS) infants and 90 control mothers. The comparison of both groups of mothers is a new way to determine if those mutations and their interactions increase the risk for DS. Material came from the case-control network of the Spanish Collaborative Study of Congenital Malformations (ECEMC). Using a general lineal model in a backwards step, we performed the analyses including the different mutations, maternal age, the fact that each mother had a DS or a control infant, and all possible interactions of these variables, in the models, being maternal Hcy the continuous dependent variable. In another model, maternal folic acid intake during the third trimester of pregnancy was added. The results from both models were essentially the same: Hcy levels variability differs from case mothers to control ones, the presence of the MTHFR1298A > C polymorphism also affects significantly the Hcy variance, as it does the statistical interaction between the mutations MTRR66A > G and MTHFR1298A > C in the mother. In this sense, the interaction between different polymorphisms may totally modify their individual effects, and some of those effects are different in mothers of DS children and in controls' mothers. For instance, only two mutations in MTRR66 (GGAA) in mothers of control infants increase the reference maternal Hcy level in 4.66 units, and the individual effect of the genotype with only two mutations in the MTHFR1298 gene (AACC) increases the reference Hcy level in 12.74 units. However, the presence of the four mutations (GGCC) interacts giving a statistically significant decrease in 6.00 units in the level of Hcy in control mothers. On the contrary, in mothers of DS infants, the sole presence of two mutations in one of these two genes decreases the levels of Hcy (-2.31 units for GGAA genotype, and -3.43 units for AACC genotype), while the presence of the four mutations (GGCC) increases Hcy in 9.53 units. Taking into consideration that in the one-carbon metabolism cystathionine beta-synthase (CBS) catalyzes Hcy in an irreversible way, and that CBS gene is located in chromosome 21, fetuses and infants with DS have functional folate deficiency due to overexpression of CBS. This fact, as well as others influencing Hcy levels (such as nutrients interactions and lifestyle), together with the fetal genotype, suggest that their relationship with DS could be through an effect on fetal survival up to birth. Three possible mechanisms are considered by evaluating the results in the light of the present knowledge on cytology and molecular biology.

Field theory provides a rational basis for birth defects terminology. During blastogenesis in higher metazoa, pattern formation in the primary field leads to the establishment of upstream expression domains of growth and transcription factors, which, in various permutations and at specific sites and times, lay down the pattern of progenitor fields. Further spatially coordinated, temporally synchronized, and epimorphically hierarchical morphogenetic events, mostly during organogenesis, lead to the attainment of final form in the secondary, epimorphic fields. Because of shared molecular determinants, spatial contiguity, and close timing of morphogenetic events during blastogenesis, most malformations arising during blastogenesis are polytopic, i.e., involving two or more progenitor fields, e.g., acrorenal, cardiomelic, gastromelic, or splenomelic anomalies. Defects of organogenesis tend to be monotopic malformations, e.g., cleft palate or postaxial polydactyly. We suggest that what were called "associations" (e.g., VATER, schisis) be designated primary polytopic developmental field defects, or simply polytopic field defects, and that the term "association" be reserved for the original definition of a statistical combination of anomalies (mostly of organogenesis) [Spranger et al. (1982): J Pediatr 100:160-165]. If genetically caused or predisposed, all structures involved in a polytopic or monotopic malformation are genetically abnormal, whereas the parts secondarily affected as a consequence of a malformation sequence (e.g., spina bifida) are genetically normal. Polytopic field anomalies, per se, must be distinguished from pleiotropy, although such anomalies may constitute a part of pleiotropy (e.g., in trisomy 18). Because they are downstream from pattern-forming events in the primary field, multiple anomalies of organogenesis more likely represent syndromal pleiotropy.

Opitz [BD:OAS XXIX(1):3-37, 1993] has postulated that during early blastogenesis the entire embryo represents a single morphogenetic unit, the primary field. During this period, beginning gastrulation, the most important events are the formation of the midline and the mesoderm. Consequently, one could expect that dysmorphogenetic reactions of the primary field are likely to disturb more than one of the essential events of blastogenesis, such as fusion, lateralization, decussation, segmentation, morphogenetic movements, asymmetry formation, etc. I have used the 20,891 liveborn malformed infants identified by the Spanish Collaborative Study of Congenital Malformations (ECEMC) to analyze the concept of the primary field defect (DFD). The malformed children were separated into 4,679 children with only midline defects, 1,592 children with midline plus other non-midline anomalies, and 14,620 babies without midline defects. Sex, twinning, neonatal death, parental consanguinity, and other malformed first degree relatives in the family were analyzed in each group. Different defects were selected as indicators of specific morphogenetic events of blastogenesis. Cardiac and neural tube defect were selected as indicators of fusion anomalies; agenesis/hypoplasia of the corpus callosum were included as example of decussation defect; cyclopia as representation of the alteration of lateralization; vertebral defects as indicators of anomalies of segmentation; intestinal malrotation and omphalocele as representatives of the alteration of the morphogenetic movement; and, finally, infants with asplenia, polysplenia, dextrocardias, transposition of great vessels, visceral transposition, and situs inversus totalis were grouped to allow an analysis of alteration of the normal body asymmetry.(ABSTRACT TRUNCATED AT 250 WORDS)