Congenital malformations associated with anencephaly in the Fylde peninsula of Lancashire

Anencephaly and its associated malformations

INTRODUCTION

Anencephaly is a serious neural tube defect in which parts of the brain and skull are not developed. But apart from this it is also associated with other malformations which are not related to neural tube in development.

AIM

The present study was undertaken to find the associated congenital malformations in western region of India and establish a aetiological correlation.

MATERIALS AND METHODS

The study was conducted using 20 anencephalic fetuses.

RESULTS

Nearly 80% of fetuses had associated malformations. Spina bifida was seen in 9 fetuses and cleft palate in 8. Female fetus with cleft palate had other severe associated gastrointestinal and skeletal malformation.

CONCLUSION

In cases of anencephaly other associated malfor-mations like spina bifida and cleft palate are commonly seen.

Autosomal dominant polycystic kidney disease in the fetus

We report on 3 cases with a fetal presentation of autosomal dominant polycystic kidney disease (ADPKD), which illustrate the variable expression of ADPKD during fetal life. Fetus 1 was diagnosed at 20 weeks of gestation by ultrasonography; a molecular prenatal diagnosis was performed at 10 weeks on fetus 2, a sib of fetus 1; and ADPKD was an incidental finding in fetus 3 who was aborted at 16 weeks for anencephaly. All pregnancies were terminated and pathologic studies of the fetal kidneys were performed. From these cases and a review of the literature, we draw the following conclusions: (1) so far, all fetal ADPKD kidneys that have been histologically studied have shown cystic dilatations; 28/32 of these fetuses had ultrasonographic manifestations of the disease and/or had sibs with an early-onset form of it; (2) these cysts can be found in newly formed nephrons (fetus 2), predominantly in the more mature nephrons of the deep cortex (fetus 1) or more sparsely distributed in the cortex (fetus 3); these different patterns may reflect different rates of progression of the disease; (3) in contrast to the histologic findings in adult kidneys, glomeruli seem to be predominantly affected in fetal ADPKD; (4) severe fetal expression of ADPKD seems to cluster in some families; and (5) so far, all DNA analyses performed in families with subjects presenting during the fetal or neonatal period have been consistent with linkage to the PKD1 locus.

Anencephaly and limb deficiencies

Limb deficiencies (LDs) are rarely reported in anencephalic infants. A review of 662 patients in the literature on non-neural defects in anencephaly only showed five patients with LDs. We report on eight patients with various LDs from the records of 141 necropsies of the anencephalic infants found among 495,830 births. Compared with another group of anencephalic infants reported in the literature, the patients in this group of anencephalic infants with LDs were predominantly male, their mean gestational age was younger by approximately 5 weeks, their mean birth-weight was approximately 1,400 g less, and they presented with a higher incidence of polyhydramnios during gestational development. The association of this pair of anomalies, which was 100 times more frequent than expected, seems not due to chance. Since all eight patients had other multiple congenital anomalies (MCA), in addition to anencephaly and LDs, the postmortem study should be mandatory in anencephalic infants with LDs. The most common associated anomalies were cardiovascular and renal defects. Oral clefts, diaphragmatic hernia, esophageal atresia, and imperforate anus were also observed in these infants. The recognition of LDs in anencephalic infants indicates severe and extensive disturbance of the early embryogenesis (blastogenesis), which affects the midline of the embryo.

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.

Hypoplastic left heart syndrome: more potential transplant recipients than suitable donors

Neonatal cardiac transplantation offers the prospect of survival for babies with hypoplastic left heart syndrome--but only if suitable donors are available. In a retrospective survey in the Northern health region of England and Wales, the likely need for neonatal cardiac transplantation far outweighed the potential availability of donors. Over 8 years (1983-90) hypoplastic left heart syndrome was identified in 38 newborn babies and in 9 fetuses in utero. Of 41 live births (including 3 diagnosed prenatally) 31 would have been candidates for a cardiac transplant, but only 4 suitable donors could be identified (3 with anencephaly born alive during the same period and 1 who died between 1979 and 1986 after a head injury). Analysis of all infant deaths in 1987-89 revealed only 3 potential donors from 426 deaths in the 3 years. Although more widespread antenatal diagnosis may lead to fewer liveborn babies with hypoplastic left heart syndrome, these findings indicate that an alternative source of donors needs to be identified before neonatal cardiac transplantation can be widely used in the treatment of this disorder.

Risks to sibs of probands with neural tube defects: data for clinic populations in British Columbia

The purpose of this study is to determine whether couples receiving genetic counselling because of a child with a neural tube defect (NTD) are a selected group and therefore not representative of the general population with respect to sib risks for NTDs. British Columbia (B.C.) provides an excellent opportunity to look at this for several reasons. Firstly, genetic counselling services are centralized. Secondly, there is virtually complete ascertainment of all infants with NTDs in the province. Thirdly, sib risks for NTDs in the general population have been derived previously [McBride, 1979] and, therefore, are available for comparison with the risks for sibships in the clinic populations. In the present study, data were available on 398 sibships in which the index case had anencephaly and/or spina bifida. In all instances, sib risks for the clinic populations did not differ significantly from those for the general population. In addition, congenital malformations other than NTDs did not occur among sibs of index cases more often than expected, based on provincial incidence data.

Congenital malformations associated with anencephaly in liveborn and stillborn infants

Records from the population-based British Columbia Health Surveillance Registry were examined, and a total of 456 infants with anencephaly (181 liveborns, 275 stillborns) were identified. Registry records list up to four congenital malformations per individual, and the records of the study cohort were reviewed for the presence of additional malformations. A total of 12.7% of infants (14.4% liveborns, 11.6% stillborns) had congenital malformations in addition to anencephaly. The frequencies of specific congenital malformations (e.g., talipes, cleft lip and/or palate, omphalocele) in infants with anencephaly were compared with the frequencies of these malformations in the general population of liveborns. In addition, the types of additional congenital malformations in liveborn anencephalics compared to stillborns were looked at. The similarity suggests that it is not just the presence of these additional congenital malformations that leads to death in utero. The data provide further evidence for etiological heterogeneity in neural tube defects.