1/17. Sirenomelia. Pathological features, antenatal ultrasonographic clues, and a review of current embryogenic theories.We aimed to discuss the prenatal diagnosis and pathological features of sirenomelia, and to review current embryogenic theories. We observed two sirenomelic fetuses that were at the 19th and 16th gestational week respectively. In the former, transvaginal ultrasound revealed severe oligohydramnios and internal abortion, whereas bilateral renal agenesis, absence of a normally tapered lumbosacral spine, and a single, dysmorphic lower limb were detected in the latter. In both cases, x-rays and autoptic examination allowed categorization on the basis of the skeletal deformity. Subtotal sacrococcygeal agenesis was present in both cases. Agenesis of the urinary apparatus and external genitalia and anorectal atresia were also found. classification of sirenomelia separately from caudal regression syndrome is still debated. Recent advances in the understanding of axial mesoderm patterning during early embryonic development suggest that sirenomelia represents the most severe end of the caudal regression spectrum. Third-trimester ultrasonographic diagnosis is usually impaired by severe oligohydramnios related to bilateral renal agenesis, whereas during the early second trimester the amount of amniotic fluid may be sufficient to allow diagnosis. Early antenatal sonographic diagnosis is important in view of the dismal prognosis, and allows for earlier, less traumatic termination of pregnancy.- - - - - - - - - - ranking = 1keywords = embryo (Clic here for more details about this article) |
2/17. Mermaid and Potter's syndrome occurring simultaneously.We herein report a case of a female embryo who died in utero and at autopsy she was found to have bilateral renal agenesis with the extrarenal manifestations of Potter's syndrome together with mermaid syndrome which is a rare combination. From all the anomalies of the upper urinary tract bilateral renal agenesis seems to have a cardinal role in the survival of the embryo afflicted with the spectrum of associated anomalies.- - - - - - - - - - ranking = 0.33333333333333keywords = embryo (Clic here for more details about this article) |
3/17. Sirenomelia with esophageal atresia.Sirenomelia, is a rare fatal condition characterized by fusion of the lower extremities. It has been suggested that sirenomelia is a severe form of caudal regression syndrome complex for which the pathogenesis is controversial. Our case is a sirenomelia associated with esophageal atresia and tracheoesophageal fistula. In the literature, it has been pointed out that the VATER association may represent a less severe form of sirenomelia but no sirenomelia case associated with esophageal atresia and tracheoesophageal fistula has been found. Finally, we detected a single large artery which diverts the blood of the embryo's caudal part to the placenta with the detailed autopsy especially with focusing on the abdominal vasculature. This vascular steal is thought to be the main pathogenic mechanism of the condition.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
4/17. Limb/pelvis hypoplasia/aplasia with skull defect (Schinzel phocomelia): distinctive features and prenatal detection.Schinzel phocomelia syndrome is characterized by limb/pelvis hypoplasia/aplasia: specifically, intercalary limb deficiencies and absent or hypoplastic pelvic bones. The phenotype is similar to that described in a related multiple malformation syndrome known as Al-Awadi/Raas-Rothschild syndrome. The additional important feature of large parietooccipital skull defects without meningocele, encephalocele, or other brain malformation has thus far been reported only in children with Schinzel phocomelia syndrome. We recently evaluated a boy affected with Schinzel phocomelia born to nonconsanguineous healthy parents of Mexican origin. A third-trimester fetal ultrasound scan showed severe limb deficiencies and an absent pelvis. The infant died shortly after birth. Dysmorphology examination, radiographs, and autopsy revealed quadrilateral intercalary limb deficiencies with preaxial toe polydactyly; an absent pelvis and a 7 x 3-cm skull defect; and extraskeletal anomalies including microtia, telecanthus, micropenis with cryptorchidism, renal cysts, stenosis of the colon, and a cleft alveolar ridge. A normal 46,XY karyotype was demonstrated, and autosomal recessive inheritance was presumed on the basis of previously reported families. This case report emphasizes the importance of recognizing severe pelvic and skull deficiencies (either post- or prenatally) in differentiating infants with Schinzel phocomelia from other multiple malformation syndromes that feature intercalary limb defects, including thalidomide embryopathy and Roberts-SC phocomelia.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
5/17. Sirenomelia dipus in a dizygotic twin.A rare case of sirenomelia in a LBW, IUGR & second of a dizygotic twin having multiple congenital anomalies is being reported. Apart from the features of sirenomelia, the newborn had a single umbilical artery, radial hypoplasia, total anorectal & urogenital agenesis and undetermined sex. The single umbilical artery had a normal origin from the iliac artery. There was no Vitelline arterial steal phenomenon. Theories put forward regarding etiopathogenesis are discussed. We conclude that the anomalies in the present case are difficult to be explained with earlier proposed theories. This puts an emphasis on reconsideration of old theory of genetic injury to the embryo by unknown factors.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
6/17. An interesting rare case of sirenomelia.In sirenomelia the caudal tissues of the foetus fail to develop because of the "stealing" of blood by a vitelline vascular shunt from the distal aorta during embryogenesis interfering with foetal development. A 25 years old 2nd gravida delivered one full term premature grossly asphyxiated baby at BS Medical College on 24-10-1998. The examination of the dead foetus revealed no genitalia, no anal nor urethral opening and having a single lower limb with the single thigh and rudimentary leg. Skiagram of the foetus corroborated it to be a case of syrenomelia.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
7/17. Sirenomelia, the mermaid syndrome--detection in the first trimester.The sirenomelia sequence with fusion, rotation, hypotrophy or atrophy of the lower limbs in combination with severe urogenital and gastrointestinal malformations is a rare and usually lethal disorder.We present the case of a 28-year-old woman, who was referred to our department because of an intraabdominal cystic structure in the 9th week of gestation. Subsequent scans confirmed the diagnosis of a sirenomelia sequence with the fusion of the lower extremities without fusion of the bones according to Stocker I classification. The size of the intraabdominal cyst decreased during follow-up. After counseling, termination of pregnancy was induced. The postmortem X-ray confirmed the ultrasound diagnosis.The exact etiological mechanism of this malformation is still unknown. An early alteration of the embryological vascular network damaging the caudal mesoderm is thought to lead to arrested development of the lower limbs and other affected organs. The cyst we saw in the 9th week might fit with this theory, either as an expression of the complex malformation of the lower abdomen or as the sonographic appearance of necrosis.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
8/17. Sirenomelia accompanying exposure of the embryo to cocaine.We have reported two cases of sirenomelia sequence associated with a history of cocaine exposure during a major part or the entire extent of the first trimester of pregnancy. The two infants were delivered during a 2 1/2-year interval in a newborn population in which prenatal cocaine exposure rose to an estimated 25%. The incidence of sirenomelia in this population was 18-fold higher than previously reported. The potential relationship between sirenomelia and cocaine exposure during the first month of pregnancy warrants further investigation.- - - - - - - - - - ranking = 0.66666666666667keywords = embryo (Clic here for more details about this article) |
9/17. Craniorachischisis totalis and sirenomelia.We report on a male infant with craniorachischisis totalis and sirenomelia, an association that seems to have been observed only 5 times before. In addition to these anomalies, the patient had hypoplasia of the phalanges of the right thumb. The pattern of associated malformations in infants with anencephaly and sirenomelia is reviewed. This condition, which combines cephalic and caudal defects of the embryo, could be considered an example of the "axial mesodermal dysplasia spectrum" and may be related to the midline developmental field concept.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
10/17. Sirenomelia in an identical twin: a case report.Sirenomelia, or the mermaid syndrome, is the most extreme example of the caudal regression syndrome. It invariably presents with lower limb fusion, sacral and pelvic bony anomalies, absent external genitalia, anal imperforation, and renal agenesis or dysgenesis. Because of the resultant oligohydramnios, these infants most often have Potter's facies and pulmonary hypoplasia. There are approximately 300 cases reported in the literature, 15% of which are associated with twinning, most often monozygotic. The syndrome of caudal regression is thought to be the result of injury to the caudal mesoderm early in gestation. It has been suggested that the association of the most extreme form of caudal regression, sirenomelia, with monozygotic twinning may represent developmental arrest of the primitive streak, with creation of a second primitive streak that gives rise to the usually normal twin. The embryology of the various presentations of the caudal regression syndrome may be further delineated by studying infants with this dramatic and fatal syndrome.- - - - - - - - - - ranking = 0.16666666666667keywords = embryo (Clic here for more details about this article) |
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