Clusters of sirenomelia in South America.

BACKGROUND: One hospital in the city of Cali, Colombia, of the ECLAMC (Latin-American Collaborative Study of Congenital Malformations) network, reported the unusual occurrence of four cases of sirenomelia within a 55-day period. METHODS: An ECLAMC routine for cluster evaluation (RUMOR) was followed that included: calculations of observed/expected ratios, site visits, comparison with comprehensively collected local, South American, and worldwide data, cluster analysis, and search for risk factors. RESULTS: All four Cali sirenomelia cases were born to mothers living in a 2 km(2) area, in neighboring communes, within the municipality of Cali. Considering the total births of the city of Cali as the denominator, and based on ECLAMC baseline birth prevalence rates (per 100,000) for sirenomelia (2.25, 95% CI: 2.66, 3.80), the cluster for this congenital abnormality was unlikely to have occurred by chance (observed/expected ratio = 5.77; 95% CI: 1.57-14.78; p = .002). No consistent common factor was identified, but vicinity to an open landfill as the cause could not be rejected. Another ECLAMC hospital in San Justo, Buenos Aires, Argentina, reported three further cases but these did not seem to constitute a nonrandom cluster. CONCLUSIONS: The methodology used to evaluate the two possible clusters of sirenomelia determined that the Cali sirenomelia cluster was unlikely to have occurred by chance whereas the sirenomelia cluster from San Justo seemed to be random.

Sirenomelia and cyclopia cluster in Cali, Colombia.

Sirenomelia and cyclopia share etiologic and pathogenic characteristics. A cluster of these two patterns of malformation in the city of Cali, Colombia, is described. Four sirenomelia and four cyclopia cases were born within a 165 days period in one hospital in Cali. The lapse between conception dates of first and last cases was shorter for sirenomelia (53 days) than for cyclopia (231 days). Based on ECLAMC (Latin American Collaborative Study of Congenital Malformations) published data, the observed/expected ratio (5.7) for both defects is statistically significant (P < 0.001). Mother's residence during the first trimester of pregnancy is concentrated in a same city quarter for four of the eight cases, close to a know polluting active landfill, and the other four cases, along the Cauca river, downstream from this landfill. Birth prevalence rates for two sentinel anomalies, that is, anal and esophageal atresia for sirenomelia and oral clefts for DeMyer holoprosencephaly spectra, were not higher in Cali than in the rest of ECLAMC material. The Computer Assisted Telephone Interviewing was applied to mothers of the 8 patients, and 32 matched controls. Seven of 295 variables were associated with sirenomelia, 3 of them related to house tap water, one to exposure to street drugs, one to physical injury, and 2 secondary to abnormal pregnancy outcome. None was associated with cyclopia. Results from hair dosage of heavy metals in the 8 patient's mothers were inconsistent. The time-space cluster is nonrandom for sirenomelia, and possibly random for cyclopia. The polluting landfill remains as a possible etiological factor.

Unusual case of epigastric heteropagus twinning.

Asymmetrical conjoined twins or heteropagus twins are extremely rare. They are characterized by an incomplete component (parasite) that is normally smaller and dependent on the host (autosite). In cases of an epigastric heteropagus twin, the insertion occurs in the epigastrium. There are few reports of epigastric heteropagus twinning in the English-language literature. The authors report an extremely rare case of epigastric heteropagus twinning in which the parasite presented with head, thorax, and a rudimentary heart.

Caudal dysplasia sequence: severe phenotype presenting in offspring of patients with gestational and pregestational diabetes.

The association of maternal diabetes mellitus and congenital anomalies is well established. Children of insulin-dependent diabetic women have an increased risk of congenital malformations, especially major multiorgan defects. The cardiovascular, central nervous, gastrointestinal, genitourinary and musculoskeletal are the most affected body systems. Studies also show that offspring of women with gestational diabetes (specially those with fasting hyperglycaemia) tend to have higher rates of congenital anomalies. We report two cases of infants born to unrelated mothers: one with diabetes mellitus first detected during pregnancy (gestational diabetes) and the other with pregestational diabetes. Both infants had amelia of the lower limbs (suggestive of caudal dysplasia sequence), together with cardiovascular, skeletal, urinary and gastrointestinal defects. While pregestational diabetes seems to leave no doubt about its teratogenicity, the association of gestational diabetes and fetal/newborn malformations is still under discussion. Complete absence of the lower limbs has not been reported in association with gestational diabetes, but it may represent a spectrum of the caudal dysplasia sequence. The presentation of two cases with the same clinical phenotype of mothers with gestational and pregestational diabetes supports the evidence that gestational diabetes can be responsible for the development of the most severe form of the caudal dysplasia sequence.

Sirenomelia / Sirenomelia

Se presenta un caso clínico de sirenomelia, diagnosticado en el parto, en una paciente de 37 años. Se comenta frecuencia, etiopatogenia y diagnóstico

Síndrome de Potter / Potterïs syndrome

Se comunican 24 casos con diagnóstico prenatal de síndrome de Potter, reunidos en la Unidad de Ultrasonografía del Servicio y Departamento de Ginecología y Obstetricia del Hospital San Juan de Dios, en el período comprendido entre enero de 1992 y diciembre de 1997. Se destacan los aspectos clínicos, ecográficos y las malformaciones asociadas. Es importante recalcar que el síndrome tiene una mortalidad de 100 por ciento y enfatiza la necesidad de asesoramiento genético para embarazos posteriores

[Sirenomelia]. / Sirenomelia.

Sirenomelia is an uncommon congenital malformation of unknown etiology characterized by all degrees of severity in merning, malrotation, and dysgenesis of the lower limbs, combining as it does malformation with several anomalies of the external and internal organs, specially of the urogenital and gastrointestinal systems and other lumbosacral vertebral abnormalities; the severity of the associated malformations are not compatible with life. A genetic mechanism leading to sirenomelia is unlikely, due to the absence of the familial cases.

Sirenomelia: presentación de un caso / Sirenomelia: report of a case

Se reporta un caso de Sirenomelia diagnosticado en la Unidad de Perinatología del H.U.C., cuya evaluación antenatal reportó aligoamnios severo, retardo de crecimiento intrauterino y ausencia de imagen ecográfica renal. El diagnóstico se hizo en la etapa postnatal. Dentro de la clasificación de Forster, el caso en cuestión se trata del tipo Symelia Apus. Presentó además defecto abierto del tubo renal. Es de hacer notar la dificultad diagnóstica que detérmina la presencia de oligoamnios severo en estos casos, lo cual limita la evaluación de la anatomía fetal por ultrasonido. Se brinda una revisión de la literatura sobre etiopatogenia y manejo diagnóstico de los casos de Sirenomelia

Congenital diaphragmatic hernia associated with homolateral upper limb malformation: a study of possible pathogenesis in four cases.

Four cases of congenital diaphragmatic hernia associated with homolateral upper limb reduction deformities are presented and are analyzed in terms of their pathogenesis. Diaphragm and upper limb are supplied by adjacent segments of cervical neural crest, and the sensitive period for upper limb formation occurs during early neural crest development. The evidence supports the possibility of cervical neural crest injury as the underlying pathogenesis.

Sirenomelia a propósito de un caso

Se revisa bibliograficamente y se reporta un caso de sirenomelia, se trató de un recien nacido de 40.1 semanas de edad gestacional, de sexo indeterminado, a quien se le realizó la autopsia en el Hospital Carlos Andrade Marín de la ciudad de Quito (HCAM) en el mes de junio de 1994, luego de la cual definimossu etiología, cuadro clínico, diagnostico diferencial, frecuencia, expectativa de sobrevida y pronóstico. De acuerdo a nuestra revisión bibliográfica, se señala que este defecto ocurre en aproximadamente 1/60000 nacidos vivos, sin embargo un estudio retrospectivo de 10 años (1985-1994) en el HCAM, reportó de entre un total de 45000 nacidos vivos 3 casos de esta entidad lo cual corresponde a una frecuencia de 1/15000 nacimientos. El principal mecanismo patogénico atribuible a este defecto descrito, se debe a un secuestro vascular y su secuencia ha sido finalmente demostrable en nuestro caso. Finalmente recomendamos la importancia del estudio genético para posterior control y seguimiento.