Relative importance of genetic and nongenetic etiologies in idiopathic mental retardation: estimates based on analysis of medical histories

A method of analyzing subgroups of mental retardates for proportions of cases caused by nongenetic brain damage is presented here and applied to 490 Israeli retardates.
Among mild retardates in simplex and multiplex families with normal unrelated parents, most of the cases were caused by nongenetic brain damage and only a minority were caused by polygenic heredity. Among severe retardates in multiplex families with normal unrelated parents, nongenetic brain damage is probably a more important cause than is homozygosity. In all groups except two (mild retardates with normal consanguineous parents, and severe retardates with retarded parents) the contribution of nongenetic brain damage was surprisingly large.     

Passive long-latency event-related potentials in mental retardation.

Long-latency auditory event-related potentials (ERPs) were passively recorded in ten mental retardates and ten age-matched normal controls. Patients were mildly to moderately retarded and had epilepsy controlled with monotherapy, ERPs were recorded from CA-A1+A2, with 1000 and 3000 Hz tones in an "oddball" paradigm. Latency and amplitude of N1, N2, P2, and P3 components were compared in controls and retardates. All ten patients had reproducible AEPs, but these were attenuated in amplitude in four, although amplitudes did not differ significantly from controls. P3 was prolonged in latency in four patients, but patients and controls did not differ significantly. AEP latency and amplitude was not correlated with degree of retardation. These findings suggest that "cognitive" evoked potentials an be recorded passively in persons with impaired cognition, but are not correlated with intellectual ability and may not reflect specific cognitive functions.     

Respiratory and Vascular Responses to Simple Visual Stimuli in Autistics, Retardates and Normals

Experiment 1 examined changes in respiratory period, peripheral pulse amplitude and cephalic pulse amplitude in autistic, retarded and normal children as a function of stimulus novelty. The respiratory measure showed habituation in the retardates and normals but not in the autistic group. Measures of peripheral and cephalic pulse amplitude showed no habituation in any group, but a higher mean response level for autistics. Autistic children thus differed from both retarded and normal children in two respects: a failure to habituate phasic respiratory responses, and enhanced response magnitude in the vascular systems. This experiment was replicated using groups of preschool children and university students. Results indicated significant age effects in the vascular systems, with preschoolers showing enhanced response magnitude. It was thus argued that autistics may display a general developmental lag in phasic vascular response measures, and an additional specific deficit indicated by failure to habituate respiratory responses. The implications of these group differences were discussed in relation to the etiology of autistic psychopathology.     

Increased insulin concentrations in nondiabetic offspring of diabetic parents

Insulin resistance is thought by many to be the primary defect that results in non-insulin-dependent diabetes mellitus (NIDDM). An implication of this theory is that prediabetic persons have higher serum insulin levels than normal subjects. We assessed serum insulin concentrations in a cohort of 1497 nondiabetic Mexican Americans, a population at high risk for NIDDM, according to whether their parents or siblings had diabetes. It was assumed that prediabetic persons would be more likely to have strong family histories of diabetes. We found a stepwise increase in fasting insulin levels in nondiabetics with neither, one, or both parents with diabetes (69.8, 77.8, and 94.6 pmol per liter, respectively; P = 0.002). Similar results were observed for insulin sum (the total of insulin concentrations in the fasting state and at 30, 60, and 120 minutes after a 75-g oral glucose load). The differences in insulin sums according to family history remained statistically significant in analyses of covariance, which controlled for variations in body-mass index, body-fat distribution, and level of blood glucose. Subjects without diabetes who had a diabetic sibling had higher fasting concentrations of insulin than subjects without a diabetic sibling (83.2 vs. 69.6 pmol per liter), but the difference was not statistically significant. We conclude that prediabetic persons, who would be expected to be more numerous in kindreds with progressively stronger family histories of diabetes, have hyperinsulinemia. This supports the insulin-resistance hypothesis.     

Specification of social support behaviours and network dimensions along the HIV continuum for gay men

This study aimed to investigate social supports that HIV-infected persons find helpful and unhelpful, and the size and composition of networks along the disease continuum. Ninety six HIV-infected and 33 seronegative gay men were interviewed. The HIV continuum was represented by seronegative, HIV asymptomatic and symptomatic groups. Emotional and physical support were the most frequently identified helpful supports. Symptomatic persons identified physical support as helpful more often than asymptomatic persons. Availability, acceptance and nurturing were the most frequently identified helpful emotional support behaviours, while domestic support was the most frequently identified physical support behaviour. The most frequently mentioned unhelpful support was overprotectiveness. Overall, HIV-infected people had adequate social networks. Composition of the networks of HIV-infected persons differed from that of seronegative participants, in that the former had markedly more professional and family persons and fewer friends in their network. HIV education and counselling interventions should provide emotional support, facilitate physical support for symptomatic persons, offer support that matches specific needs, include significant others, incorporate peer-help and be gay-sensitive.     

The prevalence of chromosome abnormalities among mentally retarded persons in a geographically delimited area of Denmark

A cytogenetic survey of an unselected group of mentally retarded persons in a geographically limited area was made in order to establish the frequency of chromosome abnormalities within this group. In the area there were 2,157 patients, both institutionalized and living at home. A chromosome analysis was performed in 1905 cases; 359 (18.8%) of these had a chromosome anomaly: 281 (14.7%) Down's syndrome, 45 (2.4%) autosomal anomaly other than Down's, and 33 (1.8%) sex chromosome anomaly. The frequency of chromosome aberrations in relation to the whole group was higher compared with similar surveys, which leads to the conclusion that the total number of mentally retarded persons living within a limited area is determined by many factors. This means that a comparison between frequencies of abnormal chromosomes in an unselected group of mentally retarded persons is only relevant when related to the whole population living in the investigation area.     

Family influences on the development of psychological problems in teenagers

A study was designed to test the opinion that teenagers at risk of psychological disturbance can be identified on the basis of their family background. A copy of the general health questionnaire (28-question version) was sent to 322 17- and 18-year-olds registered with a semi-rural group practice. The records of all the 195 teenagers who replied, and those of their parents, brothers and sisters were examined and any record of chronic illness and psychological or social problems noted. Teenagers with family disruption, legal difficulties, parental marital problems or maternal psychiatric disorder recorded in the medical notes of their families were significantly more likely to have a high score on the general health questionnaire than those without such a record. Teenagers with high scores had attended the surgery more frequently during the previous year than those with low scores. Further work may enable more precise recording of family problems and enable a group at high risk of developing distressing psychological symptoms to be clearly identified. By early identification of this group, the general practitioner may be in a position either to prevent problems arising, or to intervene more effectively if a crisis develops.     

Teenage Alcohol Use Among Hyperactive Children: A Five Year Follow-up Study

Teenage drug use among hyperactive children was examined bycomparing a group of hyperactives to a group of children havingdifficulty in school for reasons other than byperactivity andwho were matched for age, sex, and IQ. After a 5 year follow-upperiod the hyperactives were found to drink alcohol more frequently,although there were no differences on measures of academic achievementand intellectual ability. Hyperactives as teenagers still showedevidence of hyperactivity and were rated as having more conductproblems by their parents. Those hyperactives who were treatedwith Ritalin were compared to those untreated, and even whengood and poor responders were examined separately no beneficialeffects of the drug on academic achievement, intellectual ability,or behavioral ratings were evident.     

Isolated small intestinal atresias in Latin America and Spain: epidemiological analysis

Stenosis, atresia, or absence of part of the duodenum, jejunum, or ileum are generally considered small intestinal atresias (SIAs). SIAs occur as isolated defects, in combination with other unrelated congenital anomalies, or as part of syndromes. We performed an epidemiological study of infants with isolated SIAs using data from two large congenital defects registries, one from Latin America (ECLAMC) and the other from Spain (ECEMC). The overall prevalence of SIAs is similar in both programs, being 1.32 per 10,000 livebirths in Spain and 1.29 per 10.000 livebirths in Latin America. Our results suggest that infants with isolated SIAs are characterized epidemiologically on the basis of shorter gestational age and low birthweight, an association with twinning, the parents are more frequently consanguineous, and their pregnancies are more frequently complicated by vaginal bleeding. The results also suggest an association between some maternal infections and ileal atresia. The fact that these characteristics have been observed in children with these types of anomalies occurring in different geographical areas and populations supports the conclusion that these characteristics are causally related to these defects.     

Communication within low income families and the management of asthma

This study examines the effects of communication between low income urban parents and children about a chronic disease on the extent to which parent and child effectively manage the illness. Four asthma communication factors were identified by principal component analysis. We found that mothers whose preferred language was Spanish, and families who were not receiving public assistance, communicated more frequently about asthma in general. Spanish speaking mothers and their children communicated more about potential home treatments for asthma, and the more adults in the household the less there was communication about the need for emergency services for asthma. Mothers who preferred to speak Spanish had higher levels of management of the most recent asthma attack. Those whose children communicated with them about asthma in general were higher level managers. Children who influenced their parents' decisions about school attendance, and those whose mothers were more highly educated, had higher levels of asthma attack management. More educated mothers, ones whose children were younger at the time of the onset of asthma, and one who received public assistance, were more involved "in general" in their child's asthma care.     

Population cytogenetics of autosomal fragile sites

The present investigation deals with a population chromosomal survey for autosomal fragile sites under conditions of folate deprivation in 405 mental retardates. A total of 13 ascertainments of folate sensitive autosomal fragile sites is observed, of which 10q23 fragility appears to be the most frequent. Further cytogenetic studies of normal and retarded individuals are required to help elucidate the possible phenotypic effect of these autosomal sites and mental retardation.     

Anxiety,fears, and phobias in persons with Williams syndrome

Although much research has focused on the cognitive-linguistic profile associated with Williams syndrome, studies have yet to follow up on preliminary observations suggesting increased anxiety and fears in persons with this disorder. To this aim, Study 1 compared fears in 120 participants with Williams syndrome to 70 appropriately matched persons with mental retardation of mixed etiologies. Study 2 assessed differences in parent versus child reports of fears in 36 Williams syndrome and 24 comparison group parent-child dyads. In Study 3, rates of phobia and other anxiety disorders were assessed in standardized psychiatric interviews with the parents of 51 individuals with Williams syndrome. Relative to their counterparts, persons with Williams syndrome had significantly more fears as well as a wider range of frequently occurring fears, as reported by either parents or participants themselves. Children in both groups reported more fears than their parents. Whereas generalized and anticipatory anxiety were found in 51% to 60% of the sample with Williams syndrome, specific phobia was more prevalent, with 96% showing persistent and marked fears and 84% avoiding their fears or enduring them with distress. The feasibility of cognitive-behavioral treatments for phobia is discussed, as are implications for future research.     

Anxiety,Fears, and Phobias in Persons With Williams Syndrome

Although much research has focused on the cognitive-linguistic profile associated with Williams syndrome, studies have yet to follow up on preliminary observations suggesting increased anxiety and fears in persons with this disorder. To this aim, Study 1 compared fears in 120 participants with Williams syndrome to 70 appropriately matched persons with mental retardation of mixed etiologies. Study 2 assessed differences in parent versus child reports of fears in 36 Williams syndrome and 24 comparison group parent-child dyads. In Study 3, rates of phobia and other anxiety disorders were assessed in standardized psychiatric interviews with the parents of 51 individuals with Williams syndrome. Relative to their counterparts, persons with Williams syndrome had significantly more fears as well as a wider range of frequently occurring fears, as reported by either parents or participants themselves. Children in both groups reported more fears than their parents. Whereas generalized and anticipatory anxiety were found in 51% to 60% of the sample with Williams syndrome, specific phobia was more prevalent, with 96% showing persistent and marked fears and 84% avoiding their fears or enduring them with distress. The feasibility of cognitive-behavioral treatments for phobia is discussed, as are implications for future research.     

Anxiety, Fears, and Phobias in Persons With Williams Syndrome

Although much research has focused on the cognitive-linguistic profile associated with Williams syndrome, studies have yet to follow up on preliminary observations suggesting increased anxiety and fears in persons with this disorder. To this aim, Study 1 compared fears in 120 participants with Williams syndrome to 70 appropriately matched persons with mental retardation of mixed etiologies. Study 2 assessed differences in parent versus child reports of fears in 36 Williams syndrome and 24 comparison group parent-child dyads. In Study 3, rates of phobia and other anxiety disorders were assessed in standardized psychiatric interviews with the parents of 51 individuals with Williams syndrome. Relative to their counterparts, persons with Williams syndrome had significantly more fears as well as a wider range of frequently occurring fears, as reported by either parents or participants themselves. Children in both groups reported more fears than their parents. Whereas generalized and anticipatory anxiety were found in 51% to 60% of the sample with Williams syndrome, specific phobia was more prevalent, with 96% showing persistent and marked fears and 84% avoiding their fears or enduring them with distress. The feasibility of cognitive-behavioral treatments for phobia is discussed, as are implications for future research.     

Detection of Mycoplasma and its antibodies in the blood of HIV-positive patients and in healthy persons]

The comparative study of HIV-positive and clinically healthy persons has indicated that the antigens of M. pneumoniae, M. fermentans and U. urealyticum are encountered nearly twice more frequently in the blood of HIV-infected patients than in that of healthy individuals. Mycoplasma antibodies are detected in HIV-positive persons 12 times more frequently than in healthy ones. Among the HIV-infected persons there are those who have simultaneously antigens of some Mycoplasma species.     

Fragile (X) syndrome: a study of the psychological profile in 23 prepubertal patients

In this study a further analysis of the psychological profile in the prepubertal fragile (X) (fra(X] male was performed. The results of the psycho-diagnostic examination of 23 fra(X) boys were compared to a control group of 17 males of the same age with 'non-specific' mental retardation. A number of important quantitative and qualitative differences were observed between the two groups. In the preschool age group the majority of fra(X) boys was mildly mentally retarded. In the school-age group, however, most boys were moderately to severely mentally retarded. This indication of a decline in intellectual performance with age in the fra(X) syndrome was confirmed by a longitudinal individual follow-up of seven fra(X) boys in this age group. In contrast to intellectual performance, appearance of the attention deficit disorder (or hyperkinesis), with its attendent overactivity and impulsiveness, decreases with age, and is independent of the intellectual level. Autistic behaviour was more frequently observed in the youngest fra(X) males, and was more pronounced in the moderately mentally retarded. In more than 50% of the boys of preschool age the association of hyperkinesis and autistic features was found. Language and speech development in the fra(X) syndrome is both symptomatic and specific. Beside a severe, global speech retardation, there are some distinct speech characteristics in the young fra(X) males such as rapid speech rhythm, speech impulsiveness and perseverative speech.     

Syndromes associated with deletion of the long arm of chromosome 18[del(18q)]

We studied eight persons whose karyotypes demonstrated deletion of a portion of the long arm of chromosome 18. Seven of these persons who showed the typical del(18q) syndrome had a common deletion in band 18q21, most likely band q21.3, and in at least two persons the deletion was interstitial. Another mentally retarded child, dissimilar in appearance, had a more proximal deletion within band 18q12. Two different clinical syndromes resulted from deletions of these different segments of the long arm of chromosome 18.     

Syndromes associated with deletion of the long arm of chromosome 18[del(18q)].

We studied eight persons whose karyotypes demonstrated deletion of a portion of the long arm of chromosome 18. Seven of these persons who showed the typical del(18q) syndrome had a common deletion in band 18q21, most likely band q21.3, and in at least two persons the deletion was interstitial. Another mentally retarded child, dissimilar in appearance, had a more proximal deletion within band 18q12. Two different clinical syndromes resulted from deletions of these different segments of the long arm of chromosome 18.     

The inheritance of fragile sites: apparent absence of fra(2)(q13) in the parents of three unrelated probands.

We describe the inherited folate sensitive fragile site, fra(2)(q13), in three unrelated mentally retarded children, two of them with different forms of epilepsy. Fra(2)(q13) was detected in one healthy sib of one of the probands. Except for one cell in one of the fathers, fra(2)(q13) could not be detected in any of the six parents, who were repeatedly studied using methods known to induce fragile sites of this type. These findings suggest that fra(2)(q13) is not associated with the clinical features of our patients and can be transmitted by persons not expressing it. The expression of fra(2)(q13) may be age dependent.     

A test of the immunoreactive theory of the origin of neurodevelopmental disorders: Is there an antecedent brother effect?

Gualtieri and Hicks (1985) proposed that male vulnerability to neurodevelopmental disorders (NDs) could be explained by maternal immune attack on the male fetus, especially among children whose mothers had previously conceived boys as opposed to girls. This antecedent brother effect was attributed to the build‐up of maternal antibodies against previous male fetuses. Our sample consisted of 11,578 mother‐child pairs who were followed up until 7 years old. For only one ND—mental retardation—was there a true antecedent brother effect: Mentally retarded boys were significantly more likely to have antecedent brothers than sisters, whereas mentally retarded girls did not show this effect. Moreover, the incidence of mental retardation was elevated significantly among boys with at least two, as opposed to one, antecedent brothers. This did not occur among boys with antecedent sisters or in girls irrespective of antecedent sibling gender or number. This supports Gualtieri and Hicks's immunoreactive theory for the origin of NDs for only one specific ND: mental retardation.