1/11. prenatal diagnosis of smith-lemli-opitz syndrome in a pregnancy with low maternal serum oestriol and a sex-reversed fetus.A cytogenetically normal male fetus was subsequently found to have female external genitalia, a cardiac malformation and mid-trimester intra-uterine growth retardation by ultrasound examination. The maternal serum oestriol level was low. The combination of low oestriol and sonographic findings suggested Smith Lemli Opitz syndrome (SLO), which was confirmed by a markedly increased amniotic fluid level of 7-dehydrocholesterol. We review the differential diagnosis of apparent sex reversal in a fetus and low maternal serum oestriol level. To further examine the specificity of low maternal oestriol level as a marker for SLO a follow-up study of 12141 pregnancies screened for down syndrome using three biochemical markers: alpha-fetoprotein, beta-human chorionic gonadotrophin and oestriol was performed. 26 pregnancies had an oestriol level that was 0.25 MoM or less. SLO was not diagnosed clinically in any of the liveborn children ascertained through a low maternal oestriol level. Nine of the pregnancies ended in spontaneous miscarriage. Although the frequency of SLO in pregnancies with low maternal oestriol levels or sex-reversed fetuses is unknown, the diagnosis of SLO should, nevertheless, be considered in both clinical settings.- - - - - - - - - - ranking = 1keywords = pregnancy (Clic here for more details about this article) |
2/11. Equine type estrogens produced by a pregnant woman carrying a smith-lemli-opitz syndrome fetus.The equine-type estriols 1,3,5(10),7-estratetraene-3,16alpha,17beta-triol (16alpha-hydroxy-17beta-dihydroequilin) and 1,3,5(10),6,8-estrapentaene-3,16alpha,17beta-triol (16alpha-hydroxy-17beta-dihydroequilenin) constituted over half of the estrogens excreted by a woman carrying a smith-lemli-opitz syndrome (SLOS) affected fetus. The steroids were characterized by gas chromatography-mass spectrometry (GC/MS), and mass spectra of the dehydro estriols as trimethylsilyl ethers are illustrated. SLOS is associated with 7-dehydrocholesterol (7DHC), delta 7-reductase deficiency; the enzyme catalyzing the final step in cholesterol biosynthesis. Identification of these equine estrogens show that an estrogen biosynthetic pathway parallel to normal is functional in the feto-placental unit and uses 7DHC as precursor, therefore P450scc, P450c17, and 3betaHSD and P450arom are all active on 7-dehydrometabolites. patients with affected fetuses have low plasma estriol values (probably due to deficient production of the cholesterol precursor) and this is often a warning sign which instigates further evaluation for SLOS. The estriol deficiency is not quantitatively made up by the dehydrometabolites, and the combined excretion was found to be about one-third of the mean of gestational age matched controls. The importance of these findings lies in the potential value of dehydroestriol measurement for non-invasive diagnosis of SLOS at mid-gestation. Currently diagnosis relies on imaging, since SLOS is a malformation syndrome, and measurement of 7DHC levels in amniotic fluid and chorionic villus tissue.- - - - - - - - - - ranking = 0.20192798154209keywords = gestation (Clic here for more details about this article) |
3/11. Fetal demise with smith-lemli-opitz syndrome confirmed by tissue sterol analysis and the absence of measurable 7-dehydrocholesterol Delta(7)-reductase activity in chorionic villi.smith-lemli-opitz syndrome (SLOS), an autosomal recessive condition with multiple malformations, mental retardation, and growth failure, results from markedly reduced activity of the final enzyme in the cholesterol biosynthetic pathway, 7-dehydrocholesterol Delta(7)-reductase (DHCR7). We diagnosed SLOS in a fetus following intrauterine demise at 32 weeks' gestation. Chorionic villus (CV) sampling had been performed at 30 weeks because oligohydramnios and atrioventricular septal defect were noted on fetal ultrasound. On fetal post-mortem examination, a midline U-shaped soft palate cleft, micrognathia, postaxial polydactyly of the fingers with single transverse palmar creases bilaterally, and cutaneous syndactyly of toes two-three bilaterally suggested SLOS. We hypothesized that SLOS could be confirmed by analysis of tissue sterols despite extensive autolysis, and by measurement of enzyme activity in CV cells. Measurement of DHCR7 activity in CV cells was undertaken using ergosterol as a substrate. CV cells were unable to convert any ergosterol to brassicasterol after a 72 h incubation period while control CV cells reduced 12.6-71.8% of ergosterol to brassciasterol in a 72 h period. SLOS was confirmed by measurement of elevated 7-dehydrocholesterol (7-DHC) in the CV cells. Measurements of sterols were made in multiple fetal tissues. All tissues analysed showed elevated 7-DHC with markedly increased 7-DHC/cholesterol ratios.- - - - - - - - - - ranking = 0.10096399077105keywords = gestation (Clic here for more details about this article) |
4/11. Homozygosity for the W151X stop mutation in the delta7-sterol reductase gene (DHCR7) causing a lethal form of smith-lemli-opitz syndrome: retrospective molecular diagnosis.smith-lemli-opitz syndrome (SLOS) is a multiple congenital anomalies syndrome caused by an abnormality in cholesterol metabolism. The clinical severity may vary from very mild to lethality in utero, making diagnosis difficult at both ends of the spectrum. patients with severe SLOS might often escape diagnosis because they die before the correct diagnosis is made. We describe an Austrian family whose first child died neonatally with multiple congenital anomalies. The second pregnancy was terminated because the fetus showed similar severe anomalies ultrasonographically. A further pregnancy ended in a spontaneous first trimester abortion. Clinical diagnosis of SLOS was not considered until the autopsy of the fetus of the terminated pregnancy. Because no material for biochemical testing was available we performed mutational analysis of the DHCR7 gene from paraffin-embedded tissue and a Guthrie card focusing on mutations known to cause a severe SLOS phenotype. This demonstrated homozygosity for the mutation W151X, which has been demonstrated to be a functional null mutation. Our data confirm the concept that homozygosity for functional null alleles of the DHCR7 locus results in intrauterine or perinatal lethality. Furthermore, our findings suggest the usefulness of molecular studies of stored material in similarly affected cases where no material for biochemical analysis is available.- - - - - - - - - - ranking = 0.75keywords = pregnancy (Clic here for more details about this article) |
5/11. Difficult prenatal diagnosis in mild smith-lemli-opitz syndrome.smith-lemli-opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 7-dehydrocholesterol (7DHC) reductase gene (DHCR7). We present our experience with prenatal diagnosis of an affected fetus with a very mild form of SLOS. The mother underwent prenatal diagnosis by chorionic villus (CV) sampling at 11 2/7 weeks because of having two prior affected sons with SLOS. The 7DHC/total-sterol ratio in the fetus was higher than in normal control fetuses but lower than the ratio observed in CV of three other fetuses in whom SLOS was diagnosed prenatally. The pregnancy was terminated at 13 2/7 weeks. The level of 7DHC in amniotic fluid (AF) obtained at the time of pregnancy termination was unequivocally elevated, confirming the diagnosis of SLOS. This report illustrates the difficulties with the interpretation of biochemical prenatal diagnosis based on the determination of 7DHC/total-sterol ratio in CV sample in a case of mild SLOS, whereas biochemical testing of amniotic fluid clearly manifests the biochemical defects of SLOS as early as 13 weeks of gestation.- - - - - - - - - - ranking = 0.60096399077105keywords = pregnancy, gestation (Clic here for more details about this article) |
6/11. Smith-Lemli-Opitz (RHS) syndrome: holoprosencephaly and homozygous IVS8-1G-->C genotype.smith-lemli-opitz syndrome (RHS) (SLOS, OMIM 270400) is an autosomal recessive disorder of cholesterol biosynthesis caused by mutations of the 3beta-hydroxysterol Delta(7)-Delta(8)-reductase gene, DHCR7. We report a fetus with holoprosencephaly and multiple congenital anomalies who was homozygous for the IVS8-1G-->C mutation. Following termination of pregnancy, both the elevated amniotic fluid 7-dehydrocholesterol level and the DHCR7 mutations were demonstrated. Two other newborn infants with IVS8-1G-->C/IVS8-1G-->C genotype are described. This report illustrates a severe phenotypic extreme of SLOS associated with a null genotype, underscores the complex relationship between SLOS and holoprosencephaly, and discusses the possible pathogenetic mechanisms of the development of holoprosencephaly in SLOS.- - - - - - - - - - ranking = 0.25keywords = pregnancy (Clic here for more details about this article) |
7/11. A case of smith-lemli-opitz syndrome, defect of cholesterol biosynthesis.We report the case of a child with smith-lemli-opitz syndrome. The pregnancy was complicated by prenatal growth retardation. The baby was admitted to the Neonatal intensive care Unit of Chieti when she was five months old. She showed postnatal growth retardation, trouble sucking and swallowing, microcephaly and multiple major and minor malformations, including characteristic facial features and 2-3 syndactyly of the toes. We found correlations between multiple congenital malformations, failure to thrive and low plasmatic cholesterol measurement.- - - - - - - - - - ranking = 0.25keywords = pregnancy (Clic here for more details about this article) |
8/11. Increased first trimester nuchal translucency as a prenatal manifestation of smith-lemli-opitz syndrome.Routine ultrasound examination at 11 weeks of gestation in a woman with no family history of genetic disease demonstrated increased accumulation of fluid in the fetal nuchal region. In view of the association of this defect with chromosomal abnormalities, fetal karyotyping was performed by chorion villus sampling and this demonstrated a normal 46,XY karyotype. Subsequent scans showed resolution of the nuchal fluid, and at the 20-week scan the fetal genitalia appeared to be female. fetal blood sampling confirmed a normal male karyotype and fetoscopy confirmed the presence of female external genitalia. The parents elected to terminate the pregnancy, and postmortem findings were indicative of smith-lemli-opitz syndrome. This was confirmed by the finding of increased levels of 7-dehydrocholesterol in cultured skin fibroblasts.- - - - - - - - - - ranking = 0.35096399077105keywords = pregnancy, gestation (Clic here for more details about this article) |
9/11. prenatal diagnosis of smith-lemli-opitz syndrome is possible by measurement of 7-dehydrocholesterol in amniotic fluid.amniocentesis was performed at 17.3 weeks in a pregnancy with severe intrauterine growth retardation. Cytogenetic studies on amniocytes were normal, 46,XX, and the pregnancy was continued. The diagnosis of smith-lemli-opitz syndrome was suspected in the neonatal period and confirmed by the presence of 7-dehydrocholesterol (7-DHC) in the plasma (0.4 mmol/l, normal = not detectable) associated with a low total cholesterol concentration (0.4 mmol/l, normal = 2.56 /- 0.23). Retrospective analysis of the amniotic fluid sample revealed an elevated level of 7-DHC (0.022 mmol/l; normal = undetectable). Therefore measurement of 7-DHC levels in amniotic fluid during the second trimester of pregnancy is useful for the prenatal diagnosis of smith-lemli-opitz syndrome in families at risk and should be considered in cases of severe growth retardation of unknown aetiology for which amniotic fluid is available and in which a normal chromosomal pattern in amniocytes is present.- - - - - - - - - - ranking = 0.75keywords = pregnancy (Clic here for more details about this article) |
10/11. First-trimester diagnosis of smith-lemli-opitz syndrome.We report here the prenatal diagnosis of Smith-Lemli-Opitz (SLO) syndrome in the first trimester by direct measurement of 7-dehydrocholesterol (7-DHC) in a chorionic villus (CV) biopsy. The proband was diagnosed clinically at birth and the diagnosis was confirmed biochemically by demonstrating elevated 7-DHC in plasma. The family pursued prenatal diagnosis in their fourth, fifth, and sixth pregnancies. The fourth pregnancy spontaneously miscarried at 9 weeks' gestation. Analysis in both direct and cultured curetting tissue (identified as similar to CV tissue) showed an abnormal tissue neutral sterol pattern with an elevated 7-DHC concentration. The fifth pregnancy also miscarried spontaneously at 9 weeks but no tissue of unequivocal fetal origin could be identified to allow biochemical investigation. In the sixth pregnancy, ultrasound examination at the time of CV sampling showed a thickened nuchal fold. Direct analysis of the CV sample revealed elevated levels of 7-DHC consistent with the diagnosis of SLO. The pregnancy was terminated and both fetal tissue and cultured fetal cells showed marked increases in 7-DHC, confirming the prenatal diagnosis.- - - - - - - - - - ranking = 1.100963990771keywords = pregnancy, gestation (Clic here for more details about this article) |
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