Novel ETHE1 mutation in a carrier couple having prior offspring affected with ethylmalonic encephalopathy: Genetic analysis, clinical management and reproductive outcome.

Ethylmalonic encephalopathy (EE) is an autosomally recessive inherited disorder with a relentlessly progressive decline in neurological function, usually fatal by the age of ten. It is characterised by generalised hypotonia, psychomotor regression, spastic tetraparesis, dystonia, seizures and, eventually, global neurological failure. Approximately 50 reports have been published worldwide describing this devastating disease, most involving patients of Mediterranean or Arab origin. The fundamental defect in EE likely involves the impairment of a mitochondrial sulphur dioxygenase coded by the ETHE1 gene responsible for the catabolism of sulphide, which subsequently accumulates to toxic levels. A diagnosis of EE should initiate careful genetic evaluation and counselling, particularly if the parents intend to have additional offspring. The present report describes the diagnosis of EE in a reproductive endocrinology context, where both members of a non-consanguineous couple were confirmed to be carriers of an identical A↷G mutation. This previously unknown mutation at nucleotide position c.494 resulted in an amino acid substitution, p.Asp165Gly. Although consideration was given to in vitro fertilisation, embryo biopsy and single gene pre-implantation genetic diagnosis, the couple decided to first utilise a less aggressive therapeutic approach with donor sperm insemination. Pregnancy with a low risk of EE was indeed achieved; however, the infant was affected with a different anomaly (hypoplastic left heart). As this case demonstrates, prior to the initiation of fertility therapy, genetic analysis may be used to provide a confirmatory diagnosis when EE is suspected.

Psychosocial function of driving as predictor of risk-taking behaviour.

This study examined the relation between risk-taking behaviour while driving, the psychosocial function of driving, leisure time activities, car oriented peer group interaction and educational attainment. Two thousand four hundred seventeen drivers aged 18-25, randomly selected from the Danish Driving Licence Register, participated in the study. Data was collected through a mail survey. The response rate was 60.4%. A positive significant effect on risk-taking behaviour based on the score on the psychosocial function of driving was found (p<0.001). A positive significant effect on risk-taking behaviour was also found based on driving related interaction with friends. Low structure/high impulsivity leisure time activities such as playing PC-games, doing body building and partying with friends were found to be related to increased risk-taking behaviour (p<0.01). Although risk-taking behaviour is generally condemned by society results show that risk-taking behaviour while driving can also be functional in the lives of the young drivers. Consequently, other motives than safety motives are at stake when engaging in risk-taking behaviour. Implications for preventive efforts are discussed.

Young drivers--reduced crash risk with passengers in the vehicle.

Studies have shown that the effect of passengers on accident propensity among young drivers is ambiguous--in some cases positive and some negative. In Sweden, various kinds of information are compiled in registers, including a national accident database and exposure data collected in a national investigation of the driving habits of license holders. Access to such data offers a good opportunity to study crash risks related to driving with and without passengers. This was done for drivers in three different age groups (18-24, 25-64 and >65 years) accompanied by one, two or three or more passengers. Differences in crash risk were estimated using incidence density ratios (IDRs) and 95% confidence intervals. The results show that passengers had an overall protective effect, that is, the crash risk was higher for those who drove alone, regardless of their age or gender. This protective effect increased with every extra passenger (up to eight), indicating that the more passengers in the vehicle, the safer the driving. The influence of passengers was weakest (albeit still positive) among the youngest drivers (ages 18-24 years), especially the males in that group. The protective impact showed the same pattern on all days of the week, but was most marked from Friday to Sunday for most of the drivers, regardless of age.

Practicing for and performance on drivers license tests in relation to gender differences in crash involvement among novice drivers.

PROBLEM: Young male novice drivers are overrepresented in injury motor-vehicle crashes compared to females in the same category. This difference in crash involvement is often assumed to include factors such as overestimation, risk acceptance, and sensation seeking, but it can also be related to acquisition of knowledge, skills, insight, and driving experience. Therefore, this study explored possible gender differences among 18-24-year-olds in Sweden regarding practicing as learners, outcome of the driver's tests, and crash involvement during the first year after licensure. METHOD: Data for 2005 from different sources (e.g., questionnaires, license test, and crash statistics) were examined. It was not possible to follow individual subjects through all stages or in all analyses. Nevertheless, the study design did enable scrutinization and discussion of gender differences between younger inexperienced drivers with respect to education and training, license test results, and initial period of licensure. RESULTS: Males and females assimilated tuition in different ways. Females studied more theory, pursued training in a more structured manner, practiced more elements of driving in several different environments, and participated more extensively in driving school instruction. National statistics showed that females did better on the written test but not on the driving test. Males were involved in 1.9 more injury crashes per 1,000 drivers than females during their first year of licensed driving. The proportional distribution of crash types was the same for both sexes during the first period as novice drivers, but the circumstances surrounding the accidents varied (e.g., males were involved in more night crashes). IMPACT ON TRAFFIC SAFETY: More structured training while learning appears to be one of the reasons why females initially do better than males as novice drivers. Therefore, in the future, driver education should focus not only on matters such as the amount of time spent on training and preconditioning, but also on the importance of the organization and content of the learning process.

Practicing in relation to the outcome of the driving test.

In Sweden, a written and a driving test must be passed for licensure, and these two examinations are the only means of verifying that learner drivers have acquired the competencies stipulated in the national curriculum. The present study investigated 18-24-year olds regarding the effects of personal background and mode of driver education instruction on the outcome of the driving test. This was done by analysing the following for individual subjects: data on practicing obtained using a questionnaire, and test results of license tests. The results suggest that among the candidates under study, there are equal opportunities in the context of obtaining a driver's license independent of a person's background. The rate of passing was higher for those who started behind-the-wheel training at 16 and applied to take the driving test via a driving school, than for those who started the training at an older age and applied to take the test in person. It was also found that the probability of passing the test was greater if there is successful cooperation between learner and driving school instructor, and if a large proportion of the training been devoted to the task speed adaptation.

Safety halls--an evaluation.

PROBLEM: In most countries, drivers licensing systems usually include teaching some aspects of using safety equipment (e.g., airbags and seat belts). However, there is now evidence worldwide that such education is inadequate, as indicated by, for example, the overrepresentation of young drivers who do not use seat belts. METHOD: A randomized controlled study was conducted in Sweden to evaluate the effects of visiting a facility known as a "safety hall" in combination with the mandatory skid training. The results were assessed to determine the effects of the knowledge and attitudes of learner drivers in the following subjects: airbags, securing loads, seat belts, sitting posture, speed, and tires. An experimental group and a control group comprising 658 and 668 learners, respectively, answered identical questionnaires on three different occasions (pretest, posttest 1, and posttest 2). RESULTS: The results show that, for most of the topics considered, knowledge and attitudes in both groups were better at posttest 2 than at the pretest, and in general, the best knowledge and attitudes were found in the experimental group. The combined safety/skid training seems to have had the greatest effect on seat belts and loads. The findings also indicate that the safety halls can be further improved to achieve an even better effect. IMPACT ON TRAFFIC SAFETY: The use of safety halls has improved the knowledge and attitudes of learner drivers concerning several important areas related to traffic safety. Since knowledge and attitudes are important predictors of behavior, implementing safety halls can be expected to lead to improvements, especially regarding the use of safety belts and securing loads.

A comparison of eye movement behavior of inexperienced and experienced drivers in real traffic environments.

PURPOSE: The importance of the visual system as the input channel for sensory information necessary when driving is often stated. There are several reports on differences in visual search strategies between experienced and inexperienced drivers, as well as in relation to the roadway. However, the results are ambiguous and are not sampled by similar procedures. Based on previous findings, the aim of the present study was to gain further knowledge on these differences by testing the hypotheses that inexperienced drivers, in comparison to experienced drivers, fixate closer to the vehicle, fixate more often on in-vehicle objects, spread their fixations less along the horizontal meridian, fixate more often on relevant traffic cues, and fixate more often on objects classified as potential hazards. METHODS: Data from eye-tracker recordings of visual search strategies of the driver in real-world traffic were used for the analyses. RESULTS: The results confirmed all stated hypotheses regarding differences between inexperienced and experienced drivers, with the exception of fixations closer to the vehicle, in which ambiguous results were found. CONCLUSIONS: The present study provides normative data for the understanding of the development of visual search strategies among drivers. The methodology used in the present study, i.e., to combine a quantitative analysis with a qualitative analysis proved, to be useful to compare visual search strategies among inexperienced and experienced drivers.

Typical patterns in road-traffic accidents during driver training: an explorative Swedish national study.

A new law came into force in Sweden on 1 September 1993, which makes instructor-assisted driving practice possible at the age of 16 years instead of the previous 17 years and 6 months. When the age limit was reduced, the possibility that this would lead to more road-traffic accidents (RTA) during driving practice was discussed. The aim of this study was to highlight typical road-traffic accident patterns and to discuss their potential for improved training and targeted prevention. A total of 11 variables (41 categories) descriptive of the 1081 RTA involving novice drivers and police registered during the period 1994-1999 were analysed simultaneously using in turn, two multivariate analysis techniques: the Factorial Analysis of Correspondence (FAC) and the Hierarchical Ascendant Classification (HAC). Four accident classes were identified and quantified, of which the first two were more typical of rural areas: (1). accidents in rural areas on straight stretches and related to speed limit 70 km/h (n = 306); (2). accidents in rural areas on straight stretches and high-speed related (n = 97); (3). accidents in built-up areas, low-speed related and of the type rear-end (n = 289); and (4). accidents in built-up areas, at road junctions and low-speed related (n = 380). Together, these classes point to a variety of opportunities to develop ways of working with targeted prevention. Instead of adopting a general attempt to counteract the relationship between individual variables and accidents, it is possible instead to focus on a whole context and its relationship with its typical accidents and any resulting injuries. This, in its turn, allows greater specificity in the build up of the Swedish licence and training regulations and its corresponding course curriculum.

Accident involvement among learner drivers--an analysis of the consequences of supervised practice.

It is a well-known fact that experience is important for safe driving. Previously, this presented a problem since experience was mostly gained during the most dangerous period of driving-the first years with a licence. In many countries, this "experience paradox" has been addressed by providing increased opportunities to gain experience through supervised practice. One question, however, which still needs to be answered is what has been lost and what has been gained through supervised practice. Does this method lead to fewer accidents after licensing and/or has the number of accidents in driving practice increased? There were three aims in the study. The first was to calculate the size of the accident problem in terms of the number of accidents, health risk and accident risk during practising. The second aim was to evaluate the solution of the "experience paradox" that supervised practice suggests by calculating the costs in terms of accidents during driving practice and the benefits in terms of reduced accident involvement after obtaining a licence. The third aim was to analyse conflict types that occur during driving practice. National register data on licence holders and police-reported injury accidents and self-reported exposure were used. The results show that during the period 1994-2000, 444 driving practice injury accidents were registered, compared to 13657 accidents during the first 2 years with a licence. The health risk during the period after licensing was 33 times higher and the accident risk 10 times higher than the corresponding risk during practice. The cost-benefit analysis showed that the benefits in terms of accident reduction after licensing were 30 times higher than the costs in terms of driving practice accidents. It is recommended that measures to reduce such accidents should focus on better education of the lay instructor, but not on introducing measures to reduce the amount of lay-instructed practice.

Perceived risk among parents concerning the travel situation for children with disabilities.

The aim of this study was to describe perceived risk among parents concerning the travel situation for children with disabilities, in addition to their self-reported knowledge of regulations and standards. The results from the present questionnaire study showed that entering and exiting the vehicles often required manual assistance and, thus, was perceived as risky, creating worry among parents. Parents were also worried about professional drivers' lack of knowledge about the child, incautious driving behaviour and lack of adequate safety measures. A poor postural sitting position was a problem in all vehicles. Half of the parents lacked knowledge about the regulations and standards for school transportation and Special Transport Systems. Lack of information seems to be one underlying reason for the parents' worries. Comprehensive information, focused on the special needs of children with disabilities in their transportation, would probably reduce the parents' worries significantly.