Unusual case of a fetus with congenital cystic adenomatoid malformation of the lung associated with trisomy 13

Congenital cystic adenomatoid malformation of the lung can be detected with antenatal ultrasound as hyperechogenic areas in the fetal chest. Associated extrapulmonary malformations as well as chromosomal aberrations are described as very rare. We present a case report of a fetus in the 23rd week of gestation who showed in the course of a routine ultrasound screening a large number of malformations: holoprosencephaly, arrhinencephaly, cleft palate, CCAM type III of the right inferior pulmonary lobe, ventricular septal defect and bilateral clubfeet. Chromosome analysis confirmed the suspicion of trisomy 13. The present case shows how important it is—even with malformations that are rarely accompanied by associated anomalies and which have a very good prognosis—to carry out a directed diagnosis including a fetal karyotyping. Copyright © 2003 John Wiley & Sons, Ltd.     

Three- versus two-dimensional ultrasound for nuchal translucency thickness measurements: comparison of feasibility and levels of agreement

We have determined feasibility and levels of agreement for visualizing the nuchal translucency within a time limit with three-dimensional (3D) and two-dimensional (2D) transvaginal ultrasound. A total of 213 women of median gestational age 13 weeks (range 11–14 weeks) undergoing first-trimester nuchal translucency (NT) thickness measurements with 2D transabdominal ultrasound were included in the study. Additionally all women underwent 2D and 3D transvaginal NT examination within a time limit of 90 s. These two methods were compared with each other and with our standard method (2D transabdominal ultrasound) with respect to visualization of fetal nuchal fold and to the levels of agreement. The nuchal fold was visualized by 3D and 2D transvaginal ultrasound in 85.9% (95% CI: 80.5%, 90.3%) and 25.8% (95% CI: 20.1%, 32.2%), respectively (p<0.001). There was a statistically significant underestimation of the NT by 2D transabdominal as compared with 3D transvaginal ultrasound of 0.1 mm (p<0.001), and by 3D transvaginal as compared with 2D transvaginal ultrasound of even 0.1 mm (p<0.001). 3D transvaginal ultrasound of the nuchal fold has increased feasibility to 2D transvaginal ultrasound within a short examination time and with minimal, but significant, measurement differences. Copyright © 2001 John Wiley & Sons, Ltd.     

Two unusual chromosome aberrations ascertained by sonographic anomalies

We describe two cases of sonographic abnormalities associated with unusual chromosomal aberrations. Case 1 presented with a cystic hygroma at 12 weeks' gestation. Cytogenetic analysis revealed an unbalanced complex chromosome rearrangement implicating chromosomes 6, 13 and 21 (karyotype: 47,XX,t(6;21;14)(q14;q21;q21)mat,+21) and corresponding to a complete trisomy 21. This anomaly resulted from malsegregation of a maternal balanced three-way translocation. For case 2, an alobar holoprosencephaly was identified by ultrasonography at 23 weeks' gestation. Chromosomal analysis showed a recombinant rec (13), dup q chromosome, secondary to unequal crossing-over of a paternal pericentric inversion of chromosome 13, giving rise to partial trisomy 13q (karyotype: 46,XX,rec(13)dup(13q)inv(13)(p11q21)pat). These two cases illustrate the role of ultrasound in leading to detection not only of foetal chromosomal aberrations but also of rare balanced chromosomal rearrangements presented by one of the two parents. Copyright © 2004 John Wiley & Sons, Ltd.     

Amniotic fluid enzymes in pregnancies with trisomy 21

The activities of a range of microvillous enzymes in amniotic fluid from normal pregnancies (n = 213) and those complicated by trisomy 21 (n = 26) were compared in a prospective study. Using a centrifugal analyser, the activities of leucine aminopeptidase (LAP), gamma glutamyl transferase (GGT), aspartate transferase (AST), and isoenzymes of alkaline phosphate (ALP) were measured in amniotic fluid alongside alpha fetoprotein (AFP) levels. Of the markers studied, LAP was found to be the most reliable indicator of trisomy 21. Using levels below the 5th percentile, LAP showed sensitivity 73 per cent, specificity 94 per cent, and predictive value positive 63 percent. Although these tests would not replace karyotyping in all cases, the measurement of LAP could be useful as a rapid initial screening test, particularly when amniocentesis is performed for indications other than chromosomal abnormalities.     

Cytogenetic prenatal diagnosis and its relative effectiveness in the mersey region and North Wales

The relative effectiveness of cytogenetic prenatal diagnosis in the Mersey Region and North Wales is presented by estimating the percentage detection rates of Down's syndrome annually following amniocentesis from 1978–1984 inclusive. Tables indicating the percentage of screened pregnancies, types of chromosomal aberrations detected and the occurrence of Down's syndrome in mothers in age groups of five-year intervals are also presented. The average prenatal detection rate for Down's syndrome (estimated at the time of birth) was 15–15 per cent over the years 1978–1984 and was above 22 per cent for the last two years when 44–13 per cent of all pregnancies to mothers of 35 years and over were investigated.     

Variation in the levels of pregnancy- specific β-1-glycoprotein in maternal serum from chromosomally abnormal pregnancies

Human pregnancy-specific β-1-glycoprotein (SP1) was assayed retrospectively in stored maternal serum (MS) samples from 82 chromosomally abnormal pregnancies and 377 matched controls. The median MSSP1 concentration in 48 Down's syndrome pregnancies was significantly elevated at 1.17 multiples of the control median (MOM), and significantly reduced (0.5 MOM) in a group of eight cases of unbalanced translocations. There was no significant difference in median SP1 concentrations in cases of trisomy 18, trisomy 13, balanced translocations, or sex chromosome abnormalities. A comparison with human chorionic gonadotrophin results in the same series of samples indicates that SP1 is a less sensitive predictor of Down's syndrome pregnancies.     

First-trimester maternal serum alpha-fetoprotein as a marker for fetal chromosomal disorders

We evaluated first-trimester maternal serum alpha-fetoprotein (MS-AFP) as a marker for fetal chromosomal disorders. The multicentre study was performed under the auspices of the Dutch Working Party on Prenatal Diagnosis. MS-AFP was measured in 2404 normal pregnancies and 72 chromosomally abnormal pregnancies. The median multiple of the normal median (MOM) in 32 Down's syndrome pregnancies was 0·83 with a 95 per cent confidence interval ranging from 0·60 to 1·04. The difference between the distributions of first-trimester MS-AFP in normal and Down's syndrome pregnancies was statistically significant (t-test: t = 2·34, P<0·05). Thirty-one per cent of the Down's syndrome pregnancies were found below the tenth percentile. We found no difference between normal pregnancies and pregnancies with other chromosomal disorders (eight cases with trisomy 18, MOM = 1·26; seven cases with sex chromosome abnormalities, MOM = 1·07; 22 cases with a chromosomal mosaic pattern in chorionic villi, MOM = 1·08). We conclude that first-trimester MS-AFP can discriminate between normal and Down's syndrome pregnancies, but is not an effective marker. First-trimester MS-AFP has no value as a marker for other fetal chromosomal disorders.     

一种水质污染生物监测的新方法——蝌蚪肠细胞染色体畸变分析

发展了一种水生脊椎动物蝌蚪肠细胞染色体畸变的分析方法,可作为诱变剂污染水源的早期报警系统。该方法的优点:1)灵敏度高;2)蝌蚪在我国分布广、数量多、捕捉方便、费用低、易饲养管理。尤其是蝌蚪的核型由22条大的中部和亚中部着丝点染色体所组成,适于毒理遗传学研究;3)蝌蚪具有转化前诱变剂或前致癌剂为活性成份的微粒体活化系统。     

The importance of late pregnancy scans for renal tract abnormalities

A 12-month prospective population study of antenatal patients was undertaken in a large district general hospital to assess ultrasound scanning in late pregnancy for the detection of non-lethal fetal renal abnormalities. The rate of false-negative antenatal scans during the study period was also assessed. Both 18–20 and 28–32 weeks' gestational scans were performed on 6497 pregnant women. Forty fetuses with a suspected abnormality were referred for postnatal examination and 29 neonates were found to have renal abnormalities. Of these, 21 were significant and eight were likely to be extrarenal pelves. In six, there was evidence of an abnormality at the early scan. Nine children, seven with reflux, presented within the study period, all with preceding normal antenatal scans. The incidence (0·46 per cent) of structural renal abnormalities is similar to that reported previously. A late scan is necessary for the antenatal detection of non-lethal renal abnormalities.