A Quantitative Trait Locus Associated With Cognitive Ability in Children

Quantitative trait loci (QTLs) associated with general cognitive ability ( g) were investigated for several groups of children selected for very high or for average cognitive functioning. A DNA marker in the gene for insulin-like growth factor-2 receptor (IGF2R) on Chromosome 6 yielded a significantly greater frequency of a particular form of the gene (allele) in a high- g group (.303; average IQ = 136, N = 51) than in a control group (.156; average IQ = 103, N = 51). This association was replicated in an extremely-high- g group (all estimated IQs > 160, N = 52) as compared with an independent control group (average IQ = 101, N = 50), with allelic frequencies of .340 and .169, respectively. Moreover, a high-mathematics-ability group ( N = 62) and a high-verbal-ability group ( N = 51) yielded results that were in the same direction but only marginally significant ( p = .06 and .08, respectively).

Sensory testing in leprosy: comparison of ballpoint pen and monofilaments

The 10 g monofilament has been replaced by the ballpoint pen in routine sensory testing of nerves in leprosy control in Ethiopia. Results of sensory testing between the ballpoint pen and different monofilaments on hands and feet were compared. Ballpoint pen underdiagnosis of loss of sensation was defined to occur when the pen was felt and the monofilament was not. Differences were evaluated both for individual test points (test point level) and for the test points of extremities collectively (extremity level). An extremity (either a hand or a foot) was defined as having sensory nerve function impairment (SNFI) if a supplying nerve had SNFI, which was the case when sensation was absent in two or more test points in the area supplied by that nerve. At test point level, the percentages with ballpoint pen underdiagnosis relative to the 2, 10, 20 and 50 g monofilaments were 40, 21, 9 and 7%, respectively, in the hands, and 47, 30, 15 and 7% in the feet. Ballpoint pen underdiagnosis percentages of SNFI at extremity level were 32, 18, 8 and 9% in the hands, and 37, 26, 14 and 6% in the feet. The risk of ballpoint pen underdiagnosis appears to be higher in extremities without visible damage. In conclusion, substantial levels of underdiagnosis of sensory loss with the ballpoint pen were observed. However, the consequences for the prognosis of treatment with corticosteroids in patients with the more subtle sensation loss noted here need to be established. Development and testing of guidelines is a prerequisite for the use of the ballpoint pen.

The experience of self-care groups with people affected by leprosy: ALERT, Ethiopia

This paper describes the development of self-care groups in Ethiopia by ALERT, and the successes and failures experienced in the process. The groups were started in 1995 in response to two main problems, the increasing number of people dependent on ALERT to heal their wounds despite years of health education, and the limited financial resources of ALERT for wound healing supplies. By December 1999, there were a total of 72 established groups. Group membership was voluntary. There have been a number of positive outcomes. Group members have taken up responsibility for managing and monitoring their own wounds and supplying their own wound healing materials. More attention is paid to their personal hygiene and personal appearance. They also report increased confidence to participate in society, restored dignity and self-respect, and a sense of belonging within the community. In addition, some members have started to pay more attention to their local environmental hygiene by building pit latrines and waste disposal sites. The ALERT staff involved in this initiative had to change their role from that of a leprosy service provider to a self-care group facilitator, but not all were successful in making this transition. The remaining challenge for the programme is sustainability and further development through the National Tuberculosis and Leprosy Control Programme, The Ethiopian National Association for Ex-Leprosy Patients and possibly other organizations too.

Can people affected by leprosy at risk of developing plantar ulcers be identified? A field study from central Ethiopia

In the ALERT leprosy control programme, 75 people affected by leprosy, in three different geographical areas, were investigated. Each person was documented as having anaesthesia to the 10 g monofilament. The study sought to determine why some people developed ulcers whilst others did not. According to the records, 43 had an ulcer during the last 5 years but 32 had never had an ulcer. In order to examine protective sensation on the sole of the foot, various sensory modalities were tested and the functional anatomy of the foot was examined. The results showed, as may be expected, that it is not possible to define a specific threshold for protective sensation that could be applied to all cases. Some people with only slightly diminished sensation developed ulcers, while many others with almost complete anaesthesia remained ulcer-free. In these rural communities, being a farmer reduced the risk of developing an ulcer, but no other demographic features were significant. Graded monofilaments were found to be the most appropriate test, with loss of sensation at any of five points tested being a 'positive' result. The 10 g filament was the most sensitive, but only 43% of feet identified by this test actually developed an ulcer. As people with partial loss of sensation were excluded from this study, this figure may be lower under programme conditions. The 50 g and 100 g filaments decrease the number of feet identified as at risk, but increase the percentage which actually develop an ulcer, to 46% and 49%, respectively. An appropriate test for selecting those for special programmes which may have a limited capacity, for example the provision of subsidized footwear or involvement in self-care groups, would be a 100 g filament, which would detect 86% of those feet likely to develop an ulcer, while reducing the number of those selected who are not at great risk. Vibrometry was found to be no better than graded filaments and an examination of functional anatomy did not help in identifying those at risk.

The hand-foot impairment score as a tool for evaluating prevention of disability activities in leprosy: an exploration in patients treated with corticosteroids

The hand-foot (HF) impairment score in leprosy patients is the sum of the WHO disability grades for hands and feet. This retrospective study explored the possibility of using the HF score for evaluation of the effectiveness of corticosteroid treatment programmes for nerve function impairment (NFI). Changes in the score were compared with changes in sensory testing (ST) and voluntary muscle testing (VMT) for 42 leprosy patients who received corticosteroid treatment. The WHO grade did not change in 30/60 (50%) of extremities gaining, and in 4/10 (40%) extremities losing sensation and/or muscle strength. However, 18/24 (75%) patients with a definite gain in function improved in HF score, while the HF score remained unchanged in 10/11 (91%) patients with no change in nerve function. Five patients with impairment in multiple extremities showed both gain and loss of sensation and/or muscle strength in the same or different extremities. Overall, improvement, deterioration and absence of change in NFI, as indicated by changes in ST and VMT were reflected correctly by the HF score in 28 (76%) of the remaining 37 patients. It was also shown that the HF score does not give appropriate information on the extent of the effect of corticosteroid treatment. This study illustrates that the HF score can not be used to support management of corticosteroid treatment of individual patients, but indicates this score to be a promising device for the evaluation of the effectiveness of corticosteroid treatment programmes. This study used the HF score because information on (changes in) eye impairment was not considered reliable. However, in principle, we consider the EHF score, which is the sum of the WHO disability grades for hands, feet and eyes, preferable for evaluation purposes. We strongly recommend further validation of the EHF score as a tool for evaluation of corticosteroid treatment programmes for patient groups with different distributions of NFI through prospective studies.

Dopamine markers and general cognitive ability

Because general cognitive ability (g) is among the most heritable behavioural traits, it is a reasonable target for a search for quantitative trait loci (QTLs). We used a selected-extremes design to test candidate genes for allelic association with g. Polymorphisms in four genes in the dopamine system (DRD2, DRD3, DRD4, DAT1) were genotyped for 51 high g children with IQ scores > 130 and for 51 average g control children. No significant allelic or genotypic differences were found between the high g and average g groups for these markers of the dopamine system, even though the selected-extremes design provides power to detect QTL associations that involve a relative risk of about 1.5.

No association between general cognitive ability and the A1 allele of the D2 dopamine receptor gene

Berman and Noble (1995) reported significantly reduced visuospatial performance in children with the TAQI A1 allele of the D2 dopamine receptor (DRD2) gene. Given that visuospatial performance loads highly on an unrotated principal component indexing general cognitive ability, we tested the association between DRD2 and WISC-R IQ comparing 51 high-IQ, 51 average-IQ, and 35 low-IQ children in the IQ Quantitative Trait Loci (QTL) Project. No statistically significant association between the TAQI A DRD2 alleles and IQ was found. Given that a statistically significant portion of genetic variance for specific cognitive abilities is independent of general cognitive ability, it is possible that the TAQI DRD2 association is specific to visuospatial performance and independent of general cognitive ability.