A case of ring chromosome 22 with deletion of the 22q13.3 region associated with agenesis of the corpus callosum,fornix and septum pellucidum

We report a 16-week-gestation foetus obtained by voluntary abortion after prenatal diagnosis, in which a ring chromosome 22 was observed with deletion of the 22q13.3 region. A prenatal study of the amniotic fluid by standard chromosome technique with G bands and FISH (fluorescence in situ hybridisation) was performed. After the abortion, the anatomopathological study of the obtained foetus was carried out. Morphological and histological analysis of the foetus did not reveal severe physical abnormalities, although alterations of the nervous system were observed consisting of corpus callosum, fornix and septum pellucidum agenesia. It could be that the genes in this region that were involved in the development of the central nervous system were responsible for the alterations found in the morphological study. The wide range of manifestations observed in patients with this cytogenetic alteration is probably due to size differences in the deleted region. Copyright © 2004 John Wiley & Sons, Ltd.     

Fetal abdomino-perineal lymphangioma: differential diagnosis and management

Fetal lymphangiomas are rare congenital anomalies of the lymphatic system most commonly presenting in the head and neck. Cystic abdominal lymphangiomas are more rare with only a few cases reported prenatally. We report a case of a prenatally detected abdomino-perineal lymphangioma that mimicked the more fatal prenatally detected sacrococcygeal teratoma (SCT), which resulted in one caregiver suggesting termination of the pregnancy. This case demonstrates the importance of carefully considering the differential diagnosis of fetal abdomino-perineal masses when counseling parents. Copyright © 2006 John Wiley & Sons, Ltd.     

The early prenatal sonographic diagnosis of renal agenesis: Techniques and possible pitfalls

Out of 13 252 cases in which fetal bilateral echogenic kidneys were detected by transvaginal sonography between 12 and 18 weeks' gestation, there were nine fetuses where oval hypoechogenic masses were detected in the renal bed. In five fetuses where hypoechogenic masses in the renal bed were sonographically visualized, postabortal examination was compatible with renal agenesis and the hypoechogenic masses proved to be enlarged adrenals. In three additional cases, unilateral renal agenesis was accompanied by unilateral enlarged adrenals, radiologically confirmed postnatally. In one case, a false-positive sonographic diagnosis of Potter syndrome was made because of bilateral hypoechogenic masses in the renal bed. Postabortal examination detected hypoplastic kidneys, but of normal histology, in a dyskaryotic fetus with trisomy 22. In four cases of renal agenesis, the amniotic fluid was of normal volume until the 17th week. In two of the five cases of Potter syndrome, a cystic structure, compatible with the urinary bladder, was detected in the pelvis at 14 weeks. The diagnostic criteria for renal agenesis in the early fetus differ from those used in the second half of gestation.     

Prenatal diagnosis of renal agenesis in a twin gestation

Bilateral renal agenesis is a lethal congenital anomaly. It appears to be transmitted in a polygenic pattern. The prenatal ultrasound findings consist of severe oligohydramnios, absence of the fetal bladder, and failure to identify fetal kidneys. Twin gestations with renal agenesis have been described in the paediatric literature. We detail a case of a patient with two prior affected pregnancies with bilateral renal agenesis. Her latest pregnancy was diagnosed prenatally, with one fetus with bilateral and the other fetus with unilateral renal agenesis. The ultrasound findings should be differentiated from the stuck twin phenomenon.     

Prenatal diagnosis of septal agenesis with normal pituitary function

Septal agenesis is a rare brain malformation that is characterized by partial or complete absence of the septum pellucidum, either isolated or associated with other brain anomalies. We report a case presenting with septal agenesis and normal optic chiasm and pituitary function in a fetus at 19 weeks of gestation. Copyright © 2006 John Wiley & Sons, Ltd.     

Fetal akinesia/hypokinesia sequence: Prenatal diagnosis and intra-familial variability

Intrauterine fetal movement plays a key role in normal embryonic and fetal development (Moessinger, 1983). When movement is absent or decreased, abnormal development takes place which can be appreciated in newborns and/or fetuses with the fetal akinesia/ hypokinesia sequence. This sequence is caused by a number of heterogeneous entities which result in decreased fetal movements by the action of intrinsic or extrinsic factors. Prenatal diagnosis of the akinesia/hypokinesia sequence may be possible during the second trimester through the use of real-time ultrasonographic evaluation of fetal movement. We report a family with three consecutive affected pregnancies in which the prenatal presentation of this sequence varied. Based on the phenotypic findings of the three affected fetuses, we believe that although they superficially resemble those features found in the New–Laxova syndrome, they are probably affected with a distinctly different lethal form of akinesia/ hypokinesia transmitted in an autosomal recessive fashion.     

The prenatal diagnosis of joubert's syndrome of familial agenesis of the cerebellar vermis

The prenatal diagnosis by ultrasound examination of Joubert's syndrome of familial agenesis of the cerebellar vermis is described allowing termination of pregnancy ai 26 weeks gestation. The diagnosis was made by a comparison of the prenatal ultrasound examination with computerized axial tomography obtained from the siblings with the same condition.     

Fetal liver alanine: Glyoxylate aminotransferase and the prenatal diagnosis of primary hyperoxaluria type 1

Primary hyperoxaluria type 1 (PH1) is caused by a deficiency of the hepatic peroxisomal enzyme alanine: glyoxylate aminotransferase (AGT, EC 2.6.1.44) (Danpure and Jennings, FEBS Lett., 201 , 20–24, 1986). The activity of AGT has been measured in fetal livers of gestational age 14–21 weeks. Activity increases up to 17 weeks and then levels off between 17 and 21 weeks. At this time, the mean AGT activity is about 30 per cent of the mean normal postnatal level. As in adult liver, the AGT enzyme activity and the AGT immunoreactive protein are peroxisomal. Prenatal diagnosis has been performed by measuring AGT enzyme activity and immunoreactive AGT protein on liver biopsies from two fetuses at risk for primary hyperoxaluria type 1. One was unaffected and one was affected.     

Fetal nuchal oedema and antenatal diagnosis of trisomy 10

Trisomy 10 was detected at amniocentesis undertaken following observation of fetal nuchal oedema. This is the first report of fetal trisomy 10 in association with nuchal oedema. The physical features of fetal trisomy 10 are described.     

Ultrasonic diagnosis of mediastinal cystic hygroma

The incidence of cystic hygroma, which represents dilated obstructed jugular lymph sacs, is 1 in 6000 pregnancies. Cystic hygromas can be located in the nuchal area or in any other location. The prenatal ultrasonic diagnosis of a cystic hygroma in the mediastinum is presented.