Spina Bifida and Anencephalus in Greater London

In order to make comparisons with the findings in a high frequency area, South Wales, with those in a low frequency area, south-east England, a birth frequency and family study was made of all births with neural tube malformations (spina bifida cystica, encephalocele, anencephaly, and iniencephaly) in 32 of the 33 London Boroughs over a 3-year period from 1 April 1965 to 31 March 1968. The births were ascertained through local authority registers, stillbirth and infant death certificates, and hospital records. The frequencies found were 1·54 for spina bifida (including encephalocele) and 1·41 for anencephaly (including iniencephaly). This was less than four tenths of the South Wales frequency. Evidence of an excess of winter births was found for both types of malformation, with a peak for conceptions in February, March, and April.     

Risk factors associated with neural tube defects: exposure during the first trimester of gestation

The neural tube defects (NTD) are a group of malformations of multifactorial etiology. Their high incidence in Mexico and the etiologic heterogeneity observed in several studies, prompted the present investigation with the main objective of looking for risk factors associated to NTD. We analyzed maternal exposure during the first trimester of pregnancy to different environmental factors, such as acute or chronic illnesses, immunizations, smoking, alcoholism, maternal or paternal occupation and exposure to chemicals. The sample include 360 patients with anencephaly, 249 with spina bifida and 44 with encephalocele, ascertained from a total of 230 635 live births and 4,020 stillborns, studied in the Mexican program of Registro y Vigilancia Epidemiológica de Malformaciones Congénitas Externa. Of the risk factors considered, significant differences with the control group were found for anencephaly in relation to maternal viral upper respiratory infection, hyperthermia, ingestion of analgesics, antiemetics and paternal occupation. In the case of spina bifida, significant differences were found only for viral upper respiratory infections.     

Trisomy 13 syndrome and neural tube defects

Abnormalities of the CNS, such as arhinencephaly or holoprosencephaly, are common findings in trisomy 13 syndrome. However, neural tube defects (NTDs) are rarely reported. A review of 267 patients in the literature on reported CNS developmental defects in trisomy 13 syndrome showed only 6 patients with lumbosacral NTDs. No case of encephalocele or anencephaly was found. We report on 3 patients with spina bifida from the records of 34 necropsies of karyotyped trisomy 13 syndrome, which were found among 403,710 births.     

胎儿神经系统畸形超声产前诊断分析

目的探讨胎儿神经系统畸形的超声诊断价值及临床意义。方法回顾性分析86例超声产前诊断的胎儿神经系统畸形病例的声像图特征与临床意义。结果超声产前诊断胎儿神经系统畸形86例,其中脑积水23例,无脑或露脑畸形21例,脊柱裂15例,脑或脑膜膨出8例,前脑无裂畸形7例,Dandy-Wallker畸形6例,胼胝体发育不全3例,蛛网膜囊肿2例,Galen静脉瘤1例,合并多发畸形44例,86例均经引产或出生后证实,诊断符合率100%,合并多发畸形并发畸形漏诊9例,并发症漏诊率10.47%。结论超声对产前胎儿神经系统畸形的诊断具有重要的临床价值。     

Possible X-linked anencephaly and spina bifida—report of a kindred

Causal heterogeneity of anencephaly and spina bifida has been demonstrated; in rare families the neural tube defect may be caused by a single gene. We report a family in which four cases of anencephaly or spina bifida may represent X-linked inheritance.     

CNS malformations in the kraków region. I. Birth prevalence and seasonal incidence during 1979–1981

The birth prevalence of CNS malformations in the region of Krakow from 1979 to 1981 was determined to be 1.26/1000 from records of all live- and still-birth deliveries. The frequency of anencephaly was 0.23/1,000; spina bifida and encephalocele, 0.70/1000; isolated hydrocephaly, 0.26/1,000; and other CNS anomalies, 0.06/1,000. The observed rates are below the median European level. Female preponderance was found among the probands with anencephaly, encephalomeningocele, and myelomeningocele. Cytogenetic examination of 35 newborns with CNS malformations documented normal karyotypes in all neonates. The analysis of seasonal distribution of proband's birthdate and of date of mother's last menstrual period showed no significant seasonal trend.     

Differences between the events preceding spina bifida and anencephaly.

It is usually held that there is a time continuum in the formation of monoxygotic (MZ) twins which is indexed by their placentation, running from dichorionic to monochorionic diamniotic to monochorionic monoamniotic and conjoined pairs. There is good evidence that this continuum is characterised by a continuum of predisposition to anencephaly, slightly raised in dichorionic pairs but very high in some sorts of conjoined pairs. Although MZ twins, especially monoamniotic and conjoined pairs, are peculiarly liable to anencephaly, they are not particularly susceptible to spina bifida. Among twin pairs concordant for anencephaly or spina bifida, there are strikingly few concordant in the sense of one twin having anencephaly and the other spina bifida, in contrast with the numbers of pairs concordant for the same malformation. The prevalence of anencephaly in double monsters varies with the type of monster, being high in diprosopus. These findings may be explained by the timing of embryonic events.     

Central nervous system abnormalities - contrasting patterns in early and late pregnancy

A total of 509 specimens of spontaneous abortion were studied. Of 364 complete specimens, 15(4.1%) had central nervous system (CNS) abnormalities. The defects which were seen were anencephaly, spina bifida, iniencephaly, encephalocele and anencephaly combined with complete rachischisis. A high proportion (five out of 15) had the more unusual defects of iniencephaly and encephalocele. All except one had ceased development at less than 12 weeks of gestation. Sex chromatin studies showed that males outnumbered females among CNS defective fetuses. When the month of conception was calculated for these abnormal pregnancies, summer and winter peaks were detected. Only one of the 15 patients had a family history of neural tube defect (NTD).
Histological examination of all small fetuses aborted spontaneously revealed two additional facts. First, in fetuses with a localised external CNS defect, the internal abnormality was more extensive. Second, the CNS was also abnormal in some fetuses with no visible external defect.
The proportion of abnormality is much higher than at birth and is also higher than in other surveys of spontaneous abortion.
We suggest that screening for serum alphafetoprotein should be undertaken and amniocentesis considered in pregnancies subsequent to an abortion of this type.     

Congenital absence of gluteal muscles Report of two sibs

A family is described with the following features: 1) Two propositi, a male and a female, with congenital absence of gluteal muscles and with spina bifida occulta. 2) Both parents and two apparently normal siblings with sacral spina bifida occulta. 3) Two siblings of the propositi who died soon after birth, one with anencephaly and the other with a probable spina bifida.
Two alternative hypotheses for the etiology of these malformations are suggested: first, the muscular defect could be caused by an autosomal recessive gene independent of the open neural-tube defects; second, both types of malformations could be due to the same autosomal recessive gene. Then compensatory muscular changes which allow the propositi to walk are discussed.     

A targeted sequencing panel identifies rare damaging variants in multiple genes in the cranial neural tube defect,anencephaly

Neural tube defects (NTDs) affecting the brain (anencephaly) are lethal before or at birth, whereas lower spinal defects (spina bifida) may lead to lifelong neurological handicap. Collectively, NTDs rank among the most common birth defects worldwide. This study focuses on anencephaly, which despite having a similar frequency to spina bifida and being the most common type of NTD observed in mouse models, has had more limited inclusion in genetic studies. A genetic influence is strongly implicated in determining risk of NTDs and a molecular diagnosis is of fundamental importance to families both in terms of understanding the origin of the condition and for managing future pregnancies. Here we used a custom panel of 191 NTD candidate genes to screen 90 patients with cranial NTDs (n = 85 anencephaly and n = 5 craniorachischisis) with a targeted exome sequencing platform. After filtering and comparing to our in‐house control exome database (N = 509), we identified 397 rare variants (minor allele frequency, MAF < 1%), 21 of which were previously unreported and predicted damaging. This included 1 frameshift (PDGFRA), 2 stop‐gained (MAT1A; NOS2) and 18 missense variations. Together with evidence for oligogenic inheritance, this study provides new information on the possible genetic causation of anencephaly.     

Spinal dysraphism: genetic relation to neural tube malformations.

The families of 207 index patients treated for spinal dysraphism at The Hospital for Sick Children were studied to discover whether the condition was aetiologically related to the classical neural tube malformation--spina bifida cystica and anencephaly. The index patients had all had a tethered conus medullaris and one or more of a variety of anomalies of the spinal cord, vertebrae, or skin overlying the vertebral column. Of 364 sibs of index patients, 9 had an encephaly and 6 spina bifida cystica, a pro-proportion of 4.12%. This approximates to the proportion of sibs affected by neural tube malformations in the London region when the index patients themselves have spina bifida or anencephaly. It is, therefore, appropriate that the mothers of children with spinal dysraphism should be offered prenatal screening for neural tube malformations.     

Reduction of birth prevalence rates of neural tube defects after folic acid fortification in Chile

To verify whether the decreasing neural tube defects birth prevalence rates in Chile are due to folic acid fortification or to pre-existing decreasing trends, we performed a population survey using a network of Estudio Colaborativo Latino Americano de Malformaciones Congenitas (ECLAMC, Latin American Collaborative Study of Congenital Malformations) maternity hospitals in Chile, between the years 1982 and 2002. Within each maternity hospital, birth prevalence rates of spina bifida and anencephaly were calculated from two pre-fortification periods (1982-1989 and 1990-2000), and from one fortified period (2001-2002). There was no historical trend for spina bifida birth prevalence rates before folic acid fortification, and there was a 51% (minimum 27%, maximum 66%) decrease in the birth prevalence rates of this anomaly in the fortified period. The relative risks of spina bifida were homogeneous among hospitals in the two period comparisons. There was no historical trend for the birth prevalence of anencephaly comparing the two pre-fortified periods, but the relative risks were heterogeneous among hospitals in this comparison. There was a 42% (minimum 10%, maximum 63%) decrease in the birth prevalence rate of anencephaly in the fortified period as compared with the immediately pre-fortified period, with homogeneous relative risks among hospitals. Within the methodological constraints of this study we conclude that the birth prevalence rates for both spina bifida and anencephaly decreased as a result of folic acid fortification, without interference of decreasing secular trends.     

Upper and lower neural tube defects: an alternate hypothesis.

It has been suggested that neural tube defects (NTDs) of the upper type (anencephaly, encephalocele, and thoracic spina bifida) may have a pathogenesis different from those of the lower type (lumbosacral spina bifida), since recurrent cases within a sibship were said always to be concordant with respect to NTD type. Also, spontaneous abortion, additional malformation, and recurrence rate were observed to be higher in the upper group, and there was an excess of females in upper NTD probands. To test this hypothesis, we measured the above variables in upper and lower NTDs in a sample from Quebec. We found less than full concordance (50%) of NTD type in 18 sib pairs. Recurrence rate was not significantly lower in the lower NTD group (5.6 v 5.8%). The other variables were in general agreement with previous studies, inconsistent findings possibly attributable to different NTD population incidences. These findings can be accounted for if upper and lower NTDs share a similar pathogenesis and the embryo is more susceptible during early than late neural tube formation.     

The sex ratio in spina bifida.

Published reports on the sex ratio of spina bifida have been reviewed. With one exception, there seems to be no evidence of variation in the sex ratio of spina bifida. In particular, unlike anencephaly, the sex ratio of spina bifida seems to be unrelated to the prevalence of the malformation: this (M/(M+F)) is of the order of 0.44 in respect of all spina bifida births (liveborn and stillborn). The sex ratio of spina bifida in Negroes does not seem to differ from that in whites (though the data on this point are not numerous). The exception noted above concerns spina bifida occurrring in twins: these cases are disproportionately often female. The point stands in need of explanation.     

Degree of genetic homozygosity and distribution of AB0 blood types among patients with spina bifida occulta and spina bifida aperta

Introduction

Assuming that spina bifida (SB) is a genetically controlled disease, the aim of our study was to evaluate the degree of genetic homozygosity and the distribution of AB0 blood types among patients with SB occulta and SB aperta by the homozygously recessive characteristics (HRC) test.

Material and methods

Our study included an analysis of the presence, distribution and individual combination of 15 selected genetically controlled morpho-physiological traits in a sample of 100 patients with SB (SB occulta N = 50 and SB aperta N = 50) and a control group of individuals (N = 100).

Results

We found a statistically significant difference between the mean values for genetic homozygosity (SB 4.5 ±0.3; control 3.0 ±0.2, p < 0.001) and also differences in the presence of certain individual combinations of such traits. In 12 (80.0%) of the 15 observed characteristics, recessive homozygosity was expressed to a greater degree among the group of SB patients, while for 9 (60.0%) of the traits this level of difference was statistically significant (Σ_χ ² = 266.3, p < 0.001). There was no difference in average homozygosity of such genetic markers between groups of SB occulta and SB aperta patients, but the type of individual variation in the two studied groups significantly differed. In the group of patients with SB the frequency of 0 blood group was significantly increased while B blood group was significantly decreased.

Conclusions

Our results clearly show that there is a populational genetic difference in the degree of genetic homozygosity and variability between the group of patients with SB and individuals without clinical manifestations, indicating a possible genetic component in the aetiopathogenesis of spina bifida.     

Ethnic differences in the prevalence of anencephaly and sina bifida in Boston, Massachusetts

because of the large Irish population, a group with high prevalence rates of anencephaly and spina bifida, and the small Jewish population, a group with very low prevalences of these anomalies, cases of anencephaly and spina bifida born in 1 of 4 Boston maternity hospitals were compared with a systematic 1 in 300 sample of all births in the same facilities. Estimates of prevalence were made according to ethnic group, socioeconomic status, and parity. As expected, Irish offspring showed high rates (3.1 per 1000 births) of prevalence for these congenital defects, and these rates did not change in degree if the investigation was restricted to mother only, father only, or both parents Irish heritage. If mothers were born in Ireland, however, the prevalence rate was 4.9/1000. Offspring of Jewish mothers had the lowest rates of any ethnic group examined (Protestant, Irish Catholic, Roman Catholic, and other religions), .77/1000. However, in the highest economic classes, differences between the 3 major religions were not significant. Other ancestories showed the following prevalences: Italian, 1.09; Canadian, 3.18; English, 1.49; and other U.S., 2.58. Overall in Massachusetts the rate was 3.11. Prevalence rates increased dramatically with increasing socioeconomic status. Association with parity was also noticed; parity and ehtnic group were independent associations, as were ethnic and socioeconomic class.     

Congenital vertebral anomalies: aetiology and relationship to spina bifida cystica.

A family survey of 337 patients with congenital vertebral anomalies has been carried out from the Scoliosis Clinics of Edinburgh and the Royal National Orthopaedic Hospital, London. From genetic and epidemiological evidence it is clear that multiple vertebral anomalies (without apparent spina bifida) are aetiologically related to anencephaly and spina bifida cystics, carrying a 5-10% risk to subsequent sibs for any one of these defects. The implications for prenatal diagnosis are discussed. Solitary hemivertebrae and localized anterior defects of the vertebral bodies causing kyphoscoliosis are sporadic (non-familial) in nature, carrying no risk to subsequent sibs.     

Serum associated leucocyte locomotion inhibition and leucocyte motility in malignant melanoma: effect of BCG treatment

Serum-associated leucocyte locomotion inhibition (SALLI) and leucocyte motility were investigated in patients with malignant melanoma. Ten days after tumour excision twelve out of eighteen patients' sera exhibited a SALLI exceeding the normal range of 15%. The mean SALLI thus reached was 59·2±5·2%. No correlation was observed between SALLI and the level of invasion or the stage of the disease.

Six patients selected at random who had a mean SALLI of 71·5±5·8% after tumour excision were further treated by BCG immunotherapy and presented after 8·2±2·9 months of therapy with a significantly (P<0·01) lower SALLI of 32·6±8·1%. In eight patients treated exclusively by surgical excision, SALLI remained basically unchanged in the course of 10±2·8 months (29·0±8·0% vs 30·4±12·9%).

The mean index of leucocyte locomotion (LL) of eight melanoma patients who had received BCG for 11·2±2·3 months was 5·9±0·9 cells/field and thus significantly (P<0·01) higher in comparison with the mean index of LL (2·8±0·5) found in eight patients treated by surgical excision only 12·4±2·1 months before testing.

In addition, patients receiving BCG had a significantly higher (P<0·05) mean value of LL than fifteen healthy controls who presented with a mean index of LL of 3·4±0·3 cells/field. Our results permit the suggestion that BCG decreases SALLI and increases LL in melanoma patients.

     

Distribution of chylomicrons and albumin in dog kidney

1. Under specified experimental conditions the distribution space of labelled chylomicrons in the kidney was 13·8 ± 0·9 ml./100 g. tissue. The assumption is supported that this provides a measure for the quantity of intravascular plasma constituents.

2. Values for red blood cells and albumin distribution spaces were 5·2 ± 0·6 and 20·2 ± 1·0 ml./100 g tissue, respectively, in the whole kidney. The ratio of tissue haematocrit over simultaneous arterial haematocrit averaged 0·56. The extravascular albumin fraction amounted to about 31·0% of the total albumin in the whole kidney.

3. A statistically significant correlation was demonstrated between osmotic urine/plasma (U/P) ratios (within the approximate limits of 0·6-1·8) and quantities of extravascular albumin in the medulla.

     

Increased numbers of CD5+ B cells and T cell receptor (TCR) γδ+ T cells are associated with younger age of onset in rheumatoid arthritis (RA)

Patients presenting with RA before the age of 45 years (younger onset) are known to have more aggressive disease compared with patients presenting after the age of 65 years (older onset). Coordinated expansion of circulating CD5⁺ B cell and TCR γδ⁺ T cell levels has been reported in patients with RA. This study assesses the peripheral blood levels of these two cell types in RA patients with younger and older onset of disease. CD5⁺ B cell levels were significantly elevated in the younger onset RA group (26·6 ± 4·5%) compared with the older onset RA group (14·2 ± 1·2%; P <0·01). TCR γδ⁺ T cell levels were also significantly raised in the young patients (4·0 ± 0·9%) compared with elderly patients (1·6 ± 0·2%; P <0·01). T cell levels (CD3⁺) were similar in both groups (young 66·4 ± 3·3%; old 74·3 ± 3·4% (mean ± s.e.m.); NS). Total B cell levels (CD19⁺) were also similar in these groups (7·7 ± 0·7% versus 8·9 ± 1·8%; NS). A significant positive correlation was observed between the CD5⁻ B and TCR γδ⁺ T cell types in the patients (r = 0·72, P <0.05). Compared with age-matched normal controls, the younger onset patients had similar CD5⁺ B cell and TCR γδ⁺ T cell levels to the elderly controls (CD5⁺ B cells 30·2 ± 3·0%; TCR γδ⁺ T cells 3·0 ± 0·8%). Conversely, older onset RA patients had CD5⁺ B cell levels similar to the young controls (12·3 ± 1·9%). Spontaneous in vitro synthesis of immunoglobulins (IgM, IgA and IgG) and rheumatoid factors (IgM and IgA isotypes) were not significantly different in both patient groups. The coordinate expansion of circulating CD5⁺ B cells and γδ⁺ T cells seen in patients with RA presenting before 45 years of age and not after 65 years of age may suggest a potential role for these cells in more aggressive disease states.