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 an-encephaly 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 anen-cephalic infants indicates severe and extensive disturbance of the early embryogenesis (blastogenesis), which affects the midline of the embryo. © 1992 Wiley-Liss, Inc.     

Upper limb deficiencies and associated malformations: a population-based study.

As part of an ongoing analysis of limb deficiencies occurring among 1,213,913 consecutive livebirths in British Columbia during the years 1952-1984, all cases with deficiencies of the upper limbs were analysed with a view to identifying associated patterns of anomalies. This analysis resulted in seven subgroups. For each subgroup, incidence figures for cases with and without additional anomalies were calculated separately. The proportion of cases with additional anomalies varied markedly by subgroup. For example, 89% of cases with longitudinal defects of the radius had additional malformations, while only 28% of cases with transverse defects of the radius had other organ anomalies (chi 2 = 40.55; P < 0.001, one degree of freedom). A preponderance of males was found among the cases with associated defects, particularly in the group with longitudinal defects of the radius (28 males, 14 females; chi 2 = 14.10; P < 0.001). Clustering of specific patterns of associated malformations is described within subgroups.     

Diaphragmatic defects and limb deficiencies - taking sides

Diaphragmatic defects and limb deficiencies usually occur as independent anomalies, as a polytopic field defect (in which ipsilateral anomalies might be expected) or as wider pattern of defects, potentially involving disturbance of laterality or the midline (in which bilateral or contralateral defects would occur). Data on cases from previous studies and/or the literature were used to determine whether there is an association between the sides involved in the defects. The 88 adequately described cases identified included 20 with de Lange syndrome, seven with Poland anomaly, four with trisomy 18, 52 with other patterns of multiple malformations and five with diaphragmatic and limb defects alone. Evaluation of the position of the limb (left, right, bilateral) and the diaphragmatic defects (left, right, bilateral) did not show significant association in patterns of sidedness (P = 0.48). In 56% of cases, the limb deficiencies were bilateral. Among the 32 unilateral cases, 19 (59%) were ipsilateral (15 left; 4 right) and 13(41%) were contralateral (P = 0.38). Eleven of the 13 contralateral cases had left sided diaphragmatic defects and right sided limb deficiency; four had de Lange syndrome and nine had other patterns of multiple anomalies. Only cases with Poland anomaly or otherwise isolated defects showed a trend towards ipsilateral defects. Most cases with multiple congenital anomalies, had limbs defects on both the right and left (57%) or both sides of the diaphragm were affected (an additional 10%), indicating a widespread dysmorphogenetic process rather than a more restricted field defect. In other cases, defects were bilateral or, if unilateral, reflected the propensities for diaphragmatic defects to more often involve the left side, and limb defects, the right.     

Anatomic and etiological classification of congenital limb deficiencies

Limb deficiencies, the congenital absence or hypoplasia of a long bone and/or digits, vary greatly in their anatomy and etiology. Previous attempts to classify the range of possible phenotypes have not included all types of deficiencies. We present a new classification system, which includes all potential phenotypes. Infants with limb deficiencies were identified in the hospital-based Active Malformations Surveillance Program at Brigham and Women's Hospital in Boston, MA from the years 1972 to 1974 and 1979 to 2000. Affected infants were classified based on the anatomy and apparent cause of their deficiencies. The prevalence rate of all types of limb deficiency was 0.79/1,000. Upper limb deficiencies were significantly more common than lower limb deficiencies. There was no significant difference in frequencies between deficiencies on the left and right sides of the body. Longitudinal defects were more common than terminal transverse defects; intercalary defects were uncommon. Longitudinal defects were most likely to occur on the preaxial side of the limb. Almost half of affected infants had affected digits, with normal long bones. The most common apparent cause of limb deficiencies was vascular disruption defects (0.22/1,000), such as amniotic band-related limb deficiency. This new classification system includes deficiency of each long bone, as well as absence of any finger or toe. This system will make it possible to establish the prevalence of each specific phenotype. The large number of distinct apparent causes illustrates the marked etiologic heterogeneity of limb deficiencies.     

Associated malformations in patients with limb reduction deficiencies

Infants with limb reduction deficiencies (LRD) often have other associated congenital malformations. The purpose of this investigation was to assess the prevalence and the types of associated malformations in a defined population. This study included special strengths: each affected child was examined by a geneticist, all elective terminations were ascertained, and the surveillance for malformations was continued until 1 year of age. The associated malformations in infants with LRD were collected in all livebirths, stillbirths and terminations of pregnancy during 25 years in 347,810 consecutive births in the area covered by our population based registry of congenital malformations. Of the 271 LRD infants born during this period, representing a prevalence of 7.8 per 10,000, 57.9% had associated malformations. There were 17(6.3%) patients with chromosomal abnormalities including 10 trisomies 18, and 62 (22.9%) nonchromosomal recognized dysmorphic conditions. There were no predominant recognized dysmorphic conditions, but VA(C)TER(L) association. However numerous recognized dysmorphic conditions were registered including Poland, ectrodactyly-ectodermal dysplasia-clefting, oral-facial-digital, Klippel–Trenaunay–Weber, oculo-auriculo-vertebral defect spectrum, CHARGE, Townes-Brocks, Moebius, Du Pan, Smith-Lemli-Opitz, hypoglossia-hypodactyly, amniotic band, De Lange, Rubinstein-Taybi, Fanconi, radius aplasia- thrombocytopenia, Roberts, Holt-Oram, and fetal diethylstilbestrol. Seventy eight (28.8%) of the patients were multiply, non-syndromic, non chromosomal malformed infants (MCA). Malformations in the cardiac system, in the genital system, and in the central nervous system were the most common other malformations, 11.4%, 9.4%, and 7.7% of the associated malformations, respectively, followed by malformations in the renal system (4.8%), and in the digestive system (4.6%). Prenatal diagnosis was performed in 48.4% of dysmorphic syndromes with LRD. The overall prevalence of associated malformations, which was more than one in two infants, emphasizes the need for a thorough investigation of infants with LRD.A routine screening for other malformations especially cardiovascular system, urogenital system, central nervous system, and digestive system may be considered in infants and in fetuses with LRD.     

Upper limb deficiencies and associated malformations: A population-based study

As part of an ongoing analysis of limb deficiencies occurring among 1,213,913 consecutive livebirths in British Columbia during the years 1952–1984, all cases with deficiencies of the upper limbs were analysed with a view to identifying associated patterns of anomalies. This analysis resulted in seven subgroups. For each subgroup, incidence figures for cases with and without additional anomalies were calculated separately. The proportion of cases with additional anomalies varied markedly by subgroup. For example, 89% of cases with longitudinal defects of the radius had additional malformations, while only 28% of cases with transverse defects of the radius had other organ anomalies (χ² = 40.55; P < 0.001, one degree of freedom). A preponderance of males was found among the cases with associated defects, particularly in the group with longitudinal defects of the radius (28 males, 14 females; χ² = 14.10; P < 0.001). Clustering of specific patterns of associated malformations is described within subgroups. © 1992 Wiley-Liss, Inc.     

Anencephaly with diaphragmatic hernia in sibs.

Two sibs who both had anencephaly and diaphragmatic hernia are reported. The type of diaphragmatic defect seen in anencephaly may differ from the defect seen in other babies. It is important to perform a necropsy in anencephaly.     

Psychosocial adaptation of children and adolescents with limb deficiencies: A review

Children and adolescents with congenital or acquired limb loss must contend with a number of medical and psychosocial Stressors that might be expected to increase their risk of maladjustment. Yet several studies suggest remarkably good psychosocial adjustment in this population. This paper reviews the available data on the psychosocial status of the pediatric patient with a limb deficiency. Possible explanations related to disability characteristics, such as degree of disease visibility, are offered for the reported positive outcomes. Psychosocial factors that may influence the adaptation process are also reviewed. Finally, methodological limitations of prior studies are delineated and suggestions for future research are offered. Clearly, prospective longitudinal studies with appropriate control groups are necessary for an understanding of the adaptive process in specific pediatrie groups with limb deficiencies.     

Psychological adjustment and perceived social support in children with congenital/acquired limb deficiencies

The negative impact on psychological adjustment from the chronic strain of living with limb deficiencies appears to be mediated by perceived social support. A multifactorial investigation was conducted to identify empirically psychological adjustment correlates of perceived social support in 49 children with congenital/acquired limb deficiencies. A multiplicity of adjustment factors (depression, trait anxiety, self-esteem) was variously related to perceived parent, teacher, classmate, and friend social support. Hierarchical multiple regression analyses provide initial evidence of the potentially powerful effects of the social environment of the school setting, with perceived classmate social support the only significant predictor variable across depressive symptomatology, trait anxiety, and general self-esteem. The results are discussed as the first step in identifying the potential correlates of multiple perceived social support domains, which may provide empirical guidance for future intervention studies designed to modify adjustment factors in chronically ill and handicapped children.This research was supported by grants from the Shriners Hospitals for Crippled Children Research Fund and the Milo B. Brooks Foundation for Limb Deficient Children.     

Chorionic villus sampling and transverse limb deficiencies: Maternal age is not a confounder

Advanced maternal age is a frequent indication for performing chorionic villus sampling (CVS) and it might be a confounder of the association between transverse limb deficiencies (TLD) and early CVS. We have first analyzed the maternal age-specific rates of TLD in the population monitored by the Italian Multicentric Birth Registry; then we updated a case control study controlling for maternal age. The rate of all limb deficiencies (LD) was 5.9 per 10,000 births. No trend for an excess risk for TLD or other LD with advancing maternal age was found. The relative risk for women 35 years of age and older vs. those under 35 was 0.92 (95% CI, 0.72–1.19) for any LD and 0.99 (95% CI, 0.71–1.39) for TLD. In the case control study, 11 mothers of case patients with a TLD had been exposed to CVS out of a total of 206 (5.3%), compared to 54 mothers of control patients with defects other than TLD out of a total of 12,140 (0.4%). The risk estimate for TLD associated with CVS was high in the overall analysis (OR, 12.63) and did not decrease after stratification, both in the overall sample (Mantel-Haenszel OR, 14.01) and in each gestational age stratum. Thus, advanced maternal age does not explain the association between CVS and TLD found in this study and it is unlikely to explain that observed in the several other positive studies. We recommend that any study addressing the relationship between CVS and LD should include a careful evaluation of the type of LD and the timing of CVS, and present the results for specific gestational age periods. © 1994 Wiley-Liss, Inc.     

Prenatal exposure to valproic acid during pregnancy and limb deficiencies: a case-control study

We conducted a case-control study using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC) on the relationship between prenatal exposure to valproic acid (VPA) and the presence of limb deficiencies in newborn infants. Among a total of 22,294 consecutive malformed infants (once we excluded genetic syndromes) and 21,937 control infants with specified data on antiepileptic drugs during gestation, 57 malformed infants and 10 control infants were exposed to VPA during the first trimester of pregnancy. Of the total of malformed infants exposed to VPA, 36.8% (21/57) presented with congenital limb defects of different types (including overlapping digits, talipes, clubfoot, clinodactyly, arachnodactyly, hip dislocation, pre- and postaxial polydactyly, etc.), three of them having limb deficiencies. The result of the case-control analysis shows a risk for limb deficiencies of odds ratio = 6.17 [confidence interval (CI) 1.28-29.66, P = 0.023], after controlling for potential confounder factors. If we consider that in our population the prevalence at birth of this type of defect is 6.88 per 10,000 livebirths (95% CI 6.43-7.36) we can estimate that the risk for women treated with VPA of having a baby with limb deficiencies would be around 0.42%. The limb deficiencies in the three patients exposed to VPA were the following: the first case was a newborn infant with hypoplasia of the left hand, the second patient was a newborn infant with unilateral forearm defect and hypoplastic first metacarpal bone in the left hand, and the third patient presented with short hands with hypoplastic first metacarpal bone, absent and hypoplastic phalanges, retrognathia, facial asymmetry, hypospadias, teleangiectatic angioma in skull, and hypotonia.     

Anencephaly: a retrospective analysis in Singapore. 1976 to 1980.

Records of 93 cases of anencephaly from three maternity hospitals in Singapore between 1976 and 1980 were analysed. The incidence was 0.54 per 1000 births. No significant correlation between anencephaly and local seasonal conditions could be found for Singapore.     

Human T-cell activation deficiencies.

The increasing understanding of T-cell activation is paralleled by the recognition of a growing range of 'experiments of nature' that cause T-cell activation deficiencies. Analysis of these deficiencies is, in turn, contributing to the understanding of T-cell function in vivo. Here, José Regueiro, Antonio Arnaiz-Villena and colleagues review current knowledge of structural and functional T-cell defects and the implications of these for T-cell biology.     

Stress, social support, and depressive symptomatology in children with congenital/acquired limb deficiencies

Ongoing chronic strain of living with limb deficiencies and normal daily hassles may interact to produce a negative impact on adjustment. Degree of limb loss, daily hassles/microstressors, and classmate, parent, teacher, and friend social support were investigated as predictors of depressive symptomatology in 27 children with congenital/acquired limb deficiencies. Hierarchical multiple regression analyses were utilized to test the main effects and buffering interactions effects models of the stress-social support-depressive symptomatology relationship. Degree of limb loss was not a significant predictor. Microstressors and classmate, parent, and teacher social support were all significant predictors of depressive symptomatology. None of the Stress X Social Support interaction terms were statistically significant. The overall model of stress and social support predicted 73% of the variance in depressive symptomatology.     

Anencephaly and heterotopic central nervous tissue in lungs

Heterotopic nodules of moderately well-differentiated central nervous tissue were seen in the lung of a full-term anencephalic baby who survived a few hours after birth. The pathogenesis of this rare condition remains obscure. None of the three hypotheses previously offered to explain this condition can be accepted or rejected on the basis of the recorded evidence.     

Maternal periconceptional use of multivitamins and reduced risk for conotruncal heart defects and limb deficiencies among offspring

We investigated whether a woman's periconceptional use of a multivitamin containing folic acid was associated with a reduced risk for delivering offspring with a conotruncal heart defect or a limb deficiency. Data were derived from a population-based case-control study of fetuses and liveborn infants with conotruncal or limb defects among a 1987–88 cohort of births in California. Telephone interviews were conducted with mothers of 207 (87.0% of eligible) conotruncal cases, 178 (82.0%) limb defect cases, and of 481 (76.2%) randomly selected liveborn nonmalformed control infants. Reduced risks were observed for maternal use of multivitamins containing folic acid from one month before until two months after conception. Odds ratios and 95% confidence intervals for any compared to no multivitamin use were 0.70 (0.46–1.1) for conotruncal defects and 0.64 (0.41–1.0) for limb defects. Controlling for maternal race/ethnicity, age, education, gravidity, alcohol use, and cigarette use resulted in a further reduction to the odds ratio for conotruncal defects, 0.53 (0.34–0.85), but not for limb defects. Among non-vitamin using women, consumption of cereal containing folic acid was also associated with reduced risks for both defects. Women who take multivitamins have 30–35% lower risk of delivering offspring with either conotruncal or limb defects. This association may not be attributable to folic acid specifically, but may be a consequence of other multivitamin components, or some unknown behaviors that highly correlate with regular use of a multivitamin. However, should the association prove causal, it offers an important opportunity for preventing thousands of serious birth defects. © 1995 Wiley-Liss, Inc.     

Anencephaly: Agent Orange Implications?

A case of anencephaly is presented and the question of its association with Dioxin (“agent orange”) is raised.     

Prenatal exposure to valproic acid during pregnancy and limb deficiencies: A case‐control study

We conducted a case‐control study using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC) on the relationship between prenatal exposure to valproic acid (VPA) and the presence of limb deficiencies in newborn infants. Among a total of 22,294 consecutive malformed infants (once we excluded genetic syndromes) and 21,937 control infants with specified data on antiepileptic drugs during gestation, 57 malformed infants and 10 control infants were exposed to VPA during the first trimester of pregnancy. Of the total of malformed infants exposed to VPA, 36.8% (21/57) presented with congenital limb defects of different types (including overlapping digits, talipes, clubfoot, clinodactyly, arachnodactyly, hip dislocation, pre‐ and postaxial polydactyly, etc.), three of them having limb deficiencies. The result of the case‐control analysis shows a risk for limb deficiencies of odds ratio = 6.17 [confidence interval (CI) 1.28–29.66, P = 0.023], after controlling for potential confounder factors. If we consider that in our population the prevalence at birth of this type of defect is 6.88 per 10,000 livebirths (95% CI 6.43–7.36) we can estimate that the risk for women treated with VPA of having a baby with limb deficiencies would be around 0.42%. The limb deficiencies in the three patients exposed to VPA were the following: the first case was a newborn infant with hypoplasia of the left hand, the second patient was a newborn infant with unilateral forearm defect and hypoplastic first metacarpal bone in the left hand, and the third patient presented with short hands with hypoplastic first metacarpal bone, absent and hypoplastic phalanges, retrognathia, facial asymmetry, hypospadias, teleangiectatic angioma in skull, and hypotonia. Am. J. Med. Genet. 90:376–381, 2000. © 2000 Wiley‐Liss, Inc.