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Introducción. Con frecuencia el síndrome de Turner se presenta durante el embarazo con hidrops e higroma quístico, signos de mal pronóstico y alta mortalidad. En algunos pocos casos, los signos ecográficos remiten y el feto llega a nacer vivo e incluso sobrevive la etapa perinatal. Material y métodos. Estudio descriptivo a propósito de un caso. Resultados. Presentamos un embarazo con diagnóstico ecográfico a las 25 semanas de edad gestacional de hidrops e higroma quístico severo, con cariotipo 45,X en líquido amniótico y ecocardiograma fetal normal. En los controles ecográficos ulteriores, tanto el hidrops como el higroma, remitieron casi totalmente. El embarazo llegó hasta las 36 semanas de gestación y nació una niña con signos clínicos de síndrome de Turner: edema generalizado, predominante en miembros, dorso de manos y pies, y genitales externos; piel sobrante en nuca y cuello alado. Posnatalmente se diagnosticó una coartación de aorta, patología de difícil diagnóstico por ecocardiograma fetal, por lo que frecuentemente es subdiagnosticada, y la niña fue derivada para cirugía y falleció a la edad de un mes y cinco días por una complicación posquirúrgica. Conclusiones. La evolución observada en el presente caso, así como algunos otros pocos casos descriptos en la bibliografía, nos muestran que, aún en presencia de signos ecográficos prenatales severos, no puede predecirse el pronóstico de sobrevida en fetos con síndrome de Turner, por lo que conviene ser cautos en la comunicación con los padres.

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The present knowledge of epidemiological methods, applied to assess the correlation between industrial contaminants and rates of congenital anomalies is reviewed. The concept of congenital anomalies may be extended to include other adverse reproductive outcomes, such as malformations, infant mortality, stillbirths, spontaneous abortions, intrauterine growth retardation, ectopic pregnancies, multiple births, altered secondary sex ratio, and parental sub-fertility. The review of occupational exposures associated with congenital anomalies indicated: (1) inconsistency of the reported associations; (2) more positive than negative associations; (3) solvents are the best studied, and the most frequently reported teratogenic chemicals; (4) common congenital anomalies are the most frequently studied diagnostic categories, while other defects are grouped into larger categories, with little biological meaning. The review of environmental exposures indicated that: (1) single-site studies outnumber multi-site ones; (2) results are heterogeneous; (3) congenital anomalies are, in general, unspecific, and grouped into large categories, such as those defined by anatomic systems. Recent developments in molecular biology anticipate the possibility to measure exposures directly, instead of by different "proxies", as well as to analyze the genetic predisposition for the teratogenic response to given environmental agents. The strategy of building up large banks of biological materials has already started in several birth defects registries. The following procedural guidelines to assess the teratogenicity of a pollutant are recommended: (1) strength of the association; (2) consistency of findings in different studies; (3) specificity of the association; (4) time-exposure relationship; (5) existence of a dose-response gradient between exposure and disease occurrence; (6) biological plausibility; (7) coherence of the evidence with natural history of the disease; (8) experimental (or quasi-experimental) evidence and (9) reasoning by analogy.

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A rare case of a female patient with a 47,XYY karyotype is described. She had normal female external genitalia, bilateral testes, rudimentary Fallopian tubes and no uterus. Molecular analysis revealed a normal SRY encoding sequence. The possible events in the etiology of this sex reversal entity are discussed.

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Parental consanguinity, as a recognized risk factor for congenital anomalies, has mainly been studied with a focus on the types of parental relationships and their effects on genetic syndromes or birth defects in general. The present work analyzed the association between parental consanguinity and congenital anomalies, split, when possible, into clinical subtypes, in an attempt to obtain some insight into their recognized etiological heterogeneity. The material consisted of 34,102 newborn infants, affected by one of 47 selected congenital anomaly types, ascertained by the Latin-American Collaborative Study of Congenital Malformations (ECLAMC) during the period from 1967 to 1997. The consanguinity rate for each congenital anomaly type was compared with that of the population under study (0.96%), and the potentially confounding effect of six selected variables was controlled through a conditional logistic regression analysis for those congenital anomalies significantly associated with consanguinity. Pre-occurrence rates for the same congenital anomaly in sibships of consanguineous and non-consanguineous cases were compared. A significant association with parental consanguinity was observed for three congenital anomaly types: hydrocephalus, postaxial hand polydactyly, and bilateral cleft lip +/- cleft palate, while three additional anomalies, namely, cephalocele, microcephaly, and hand + foot postaxial polydactyly, showed a positive association, but statistical significance disappeared after adjustment for confounders, probably owing to sample size reduction. The association between consanguinity and Down syndrome was mainly due to the confounding effect of maternal age, while for hydrops fetalis and 2-3 toe syndactyly, the observed positive association could not be tested for confounders due to sample size reduction.

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A sample of 53,552 nonmalformed liveborn infants was ascertained by the Latin-American Collaborative Study of Congenital Malformations between 1967 and 1996. The mean consanguinity rate was 0.96%, with significantly higher values in Brazil and Venezuela, and lower in Argentina. Low paternal education and occupation levels were positively associated with consanguinity. First-cousin matings represented almost half of all consanguineous couples. The consanguinity was mainly of more closely related types in Brazil, while in Venezuela more remote types predominated. This could reflect differences in migration patterns and rates between these two countries.

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BACKGROUND/PURPOSE: Congenital diaphragmatic hernia (CDH) is one of the most frequent causes of neonatal death because of lung hypoplasia (LH). The literature mentions a relationship between renal and pulmonary development, with higher kidney weight in presence of LH. The aims of this study were to evaluate the relationship between lung and kidney weight and to test the hypothesis of renal enlargement in fetuses and newborns with CDH. METHODS: Body weight (BW), combined kidney weight (KW), and lung weight (LW) of 52 CDH cases were established; 52 morphologically normal fetuses or newborns, matched by BW, served as a control population. Comparisons were done by covariance analysis, and a P value of less than .05 was considered as significant. RESULTS: Excluding renal abnormalities, adjusted mean kidney weights were 22.0 g (+/-1.8 SE) in CDH cases and 20.5 g (+/-1.5 SE) in controls (F = 1.05; P = .308). KW to BW ratio was lower in CDH cases than in controls (P = .023). LW was significantly lower in CDH cases than in controls. CONCLUSIONS: No significant difference between KW of CDH cases and controls could be observed. The current study provides enough evidence to reject the hypothesis of renal enlargement in cases of LH and CDH.

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Se presenta el programa de seguimiento para niños con síndrome de Down (Atención integral en niños Down: At.i.en.Do.) del Hospital "Ramón Sardá" (HMIRS). (AU)

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Se presenta el programa de seguimiento para niños con síndrome de Down (Atención integral en niños Down: At.i.en.Do.) del Hospital "Ramón Sardá" (HMIRS).

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The first step of all healthcare actions aimed at promoting an appropriate quality of life for infants affected by Down syndrome (DS) is to ensure their survival. This investigation was aimed at estimating the infant mortality rate of infants affected with DS in urban populations of South America. Thirty-three hospitals included in the Latin American Collaborative Study of Congenital Malformations (ECLAMC) distributed in 23 cities of 5 South American countries followed 360 liveborn DS cases born during the 1988-1992 period. Families were recontacted after the infant should have reached the age of one year. The collected data included information about health status; i.e., frequency and dates of diagnosed illnesses and hospital admissions, and, in case of death, information on date, place and cause of death, and illness immediately before death. Information about the interviews included place, date, and name of the interviewer. A closed questionnaire was employed by the interviewers, mostly physicians, nurses, and social workers. Life table analysis up to the age of one year was performed by the actuarial survival method. The overall mean survival at age one year was 0.736 (SE=0.023). Thirty-three (9.2%) of the 360 cases died neonatally, and 62 (17.2%) within the remaining 2-to-12-month interval. The probability of survival at one year of age did not differ between public (209 cases; mean 0.718; SE=0.031) and private (151 cases; mean: 0.762; SE=0.035) (chi2:0.87; df:1; P >0.05) health systems. The 150 DS cases with a congenital heart defect (CHD) had a significantly lower P robability of survival at the age of one year (mean: 0.660; SE: 0.039) than did the 210 cases without CHD (mean: 0.790; SE: 0.028) (chi2:6.67; df:1; P <0.01). The death rate in the first year of life for DS cases without a detected cardiac defect (21%) is significantly higher than that reported in developed countries; namely, 16% from Italy, 11% from Canada, 10% from England, and 7% from Denmark.

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This work analyzed the incidence of risk factors in 138 cases presenting two or more of five components defining VATERL, with no other recognized unrelated anomalies: vertebral anomalies, anal atresia, esophageal atresia with or without tracheoesophageal fistula, renal anomalies, and preaxial defects of the upper limbs, including polydactyly of the thumb. The 138 infants were ascertained among 1,811,461 births examined in the 1967-1994 period by the Latin-American Collaborative Study of Congenital Malformations: ECLAMC. One healthy and one malformed control newborn infant were matched to each VATERL case. The birth prevalence rates (per 100,000 births) for VATERL were significantly lower in Venezuela (3.1) than in the other eight countries (8.8) (P < 0.001). Venezuela also had lower rates for all five VATERL defects, even after excluding the 138 VATERL cases. VATERL cases were preferentially males (male proportion 0.6261) (P < 0.02), and, when compared with healthy controls, they had a higher perinatal mortality rate (63.7%) (P < 0.005), a higher frequency of fetal losses in previous pregnancies (12.6%) (P < 0.05), and lower mean birthweights (2,361.79 +/- 809.63 g) (P < 0.005). VATERL cases showed a higher rate than matched malformed controls for prenatal exposures to drugs and physical agents (P < 0.02 and P < 0.05, respectively), although no specific pharmacological or physical group was involved. The lower birth prevalence rates found in Venezuela, for VATERL as well as for each of the five congenital anomalies involved in this association, seem to be biologically meaningful. Since we could not identify a potential risk factor, nor a common cause of underascertainment unique to the Venezuelan subsample and common to all six hospitals, no hypothesis can be advanced here for this phenomenon. Nevertheless, this unequal geographic distribution strongly suggests a common etiopathogenicity for the five congenital anomalies involved in the VATERL association.

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Thalidomide, mainly used for the treatment of leprosy, is a current teratogen in South America, and it is reasonable to assume that at present this situation is affecting many births in underdeveloped countries. Moreover, the potential re-marketing of thalidomide for the treatment of a large variety of diseases may extend the problem to the developed world. When the drug is available, the control of its intake during early pregnancy is very difficult since most pregnancies are unintended. The ongoing occurrence of thalidomide embryopathy cases went undetected by the ECLAMC, due to several factors: (1) low populational coverage through this monitoring system; (2) pre-existence of the teratogen with its effects present in both baseline (expected) and monitored (observed) materials; and (3) lack of a defined phenotype to be monitored. Thus, if thalidomide re-enters the market throughout the world, due to the wide range of new applications, occurrence of phocomelia alone might not be sufficient to detect its effects. By a case-reference approach, the ECLAMC registered 34 thalidomide embryopathy cases born in South America after 1965 whose birthplaces correspond to endemic areas for leprosy. Phocomelia was found in five of eleven fully described cases. Thus, phocomelia alone is neither specific nor sufficient to serve as a suitable phenotype to survey the teratogenic effects of thalidomide. Therefore, a thalidomide-like phenotype, defined as any bilateral upper and/or lower limb reduction defect of the preaxial and/or phocomelia types, should be included in the routine surveillance of birth defects in all programmes.

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We report on a girl with developmental delay, macrocephaly, facial asymmetry, small downturned palpebral fissures, high and narrow palate, micrognathia, short neck, a heart defect, and unilateral renal agenesis. Cytogenetic analysis showed a proximal tandem duplication of the long arm of chromosome one (1q12-->q21.3). This abnormality was suggested by G- and C-banding but it was specifically characterized by fluorescent in situ hybridization (FISH). Clinical findings in our patient are compared with those of the literature in an attempt to delineate the phenotype in patients with proximal 1q duplication.

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This study departed from a preconceived definition of VACTERL, including more than one of these six anomalies in the same infant: V (vertebral anomalies), A (anal atresia), C (congenital heart disease), TE (tracheoesophageal fistula or esophageal atresia), R (reno-urinary anomalies), and L (radial limb defect). Under this definition, 524 infants were ascertained by ECLAMC from almost 3,000,000 births examined from 1967 through 1990. Observed association rates among VACTERL components as well as between VACTERL and other defects were compared against randomly expected values obtained from 10,084 multiply malformed infants (casuistic method) from the same birth sample. Conclusions were: 1) Cardiac defects are not a part of VACTERL. 2) Single umbilical artery, ambiguous genitalia, abdominal wall defects, diaphragmatic hernia, and anomalies that are secondary to VACTERL components (intestinal and respiratory anomalies, and oligohydramnios sequence defects) are frequent enough to be considered an "extension" of VACTERL, and cardiac defects should be included in this category. 3) Neural tube defects are negatively associated with VACTERL which could not be explained by selection bias or any other operational artifact. High embryonic lethality or mutually exclusive pathogenetic mechanisms could be suitable explanations. 4) Results were not clear enough to determine whether VACTERL should be defined by at least two or three component defects.

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We report on a newborn male infant who presented the typical findings of achondrogenesis type II (Langer-Saldino), and who also showed postaxial polydactyly on both feet and bilateral microtia. Polydactyly is frequently part of the short-rib syndromes, but has not been reported in achondrogenesis. The hypothesis of polydactyly as part of a contiguous gene syndrome is discussed.

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Se realizó un estudio retrospectivo de los niños con Síndrome de Down, nacidos en el Hospital Materno Infantil Ramón Sardá durante el período febrero 1988-diciembre 1990 y su relación con la edad materna. Sobre un total de 17973 nacimientos vivos y muertos se detectaron 42 niños con Síndrome de Down, correspondiendo a una incidencia total de 2.3 por ciento. Se los clasificó según edad materna y se calculó la incidencia en cada uno de los grupos etarios. En base a los resultados de este trabajo, que no difieren de los publicados por otros autores, se propone la implementación del diagnóstico cromosómico prenatal como un método más para la evaluación de la salud perinatal. (AU)

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