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The effects of maternal child-rearing attitudes, as measured by the Child Rearing Practices Report, on 5-yr.-old children's Verbal IQ and Performance IQ were investigated in a Scandinavian samp;le of 108 boys and 126 girls. The maternal child-rearing attitude of Restrictiveness, as defined by scores on the Report, showed negative relations to the cognitive measures. However, the significant negative relation between Restrictiveness and Verbal IQ, obtained for both sexes, disappeared when the effects of maternal IQ and socioeconomic status were controlled The maternal child-rearing attitude of Nurturance, as defined by scores on the Report, was significantly related to Verbal IQ and Performance IQ for boys only. Significant relationships between scores on Nurturance and cognitive abilities of boys remained when the effects of maternal IQ and socioeconomic status were controlled.

BACKGROUND:

The prevalence of thyroid disease is increased in Down's syndrome. Most available data come from cross sectional studies.

AIMS:

To study longitudinally thyroid function in patients with Down's syndrome in Uppsala county (85 patients) up to the age of 25 years.

METHODS:

Observational study based on yearly follow up in a children's clinic. Thyroid function tests were performed at each visit to the clinic.

RESULTS:

Hypothyroidism was found in 30 and hyperthyroidism was found in two of the 85 patients. No sex difference was seen. Half of the patients with hypothyroidism acquired the condition before the age of 8 years, but only one of them displayed thyroid autoantibodies at diagnosis. Most patients who developed hypothyroidism after this age had thyroid autoantibodies. In the prepubertal patients with hypothyroidism, growth velocity was lower during the year before the start of thyroxine treatment than during the year after treatment began; it was also lower than that of sex and age matched euthyroidic children with Down's syndrome.

CONCLUSION:

Thyroid dysfunction in patients with Down's syndrome is common in childhood. Consequently, annual screening is important. Autoimmune thyroid disease is uncommon in young children with Down's syndrome but is common after 8 years of age.

More than 5000, more or less rare, genetic diseases are known in man. A genetic disease is in most casesinherited from one generation to the next, and is caused by a change in the genetic code, a mutation.Once a disease gene is identified, the function of the gene and the mechanism underlying the diseasewill be better understood, allowing development of better therapeutic strategies (pharmacology andgene therapy).

Hyperkalaemic periodic paralysis (hyperPP) is an autosomal dominant disorder characterised bytransient attacks of muscle weakness or paralysis. Two Swedish pedigrees with hyperPP showedlinkage to the gene encoding the adult skeletal muscle sodium alpha subunit channel (SCN4A). Anexchange of C2188 to T was found in the two pedigrees, resulting in a substitution of methionine forthreonine.

Hypokalaemic periodic paralysis (hypoPP) is more common than the phenotypically relatedhyperPP. Thirteen families of Scandinavian origin were analysed and linkage was established to thegene for skeletal muscle calcium alpha subunit gene (CACNL1A3). Mutations were subsequentlyidentified in the patients. In all nine Danish families and in one Finnish family, a base pair substitutionwas observed, resulting in an amino acid change from arginine to histidine at position 528 in theprotein. In the remaining families, two Finnish and one Norwegian, a mutation causing replacementof arginine 1239 by histidine was found.

Sjögren-Larsson syndrome (SLS) is an autosomal recessive disorder characterised by mentalretardation, spastic di- or tetraplegia and congenital ichthyosis. By linkage analysis the SLS gene wasmapped to chromosome 17. A better genetic map of the region was established through three differentmethods: 1) by analysis of new microsatellite markers, 2) by analysis of a radiation hybrid panel to getan inter-marker order and 3) by analysis of YAC clones. Because of a founder effect, SLS is morecommon in the northern part of Sweden than in the rest of the world. The majority of Swedish SLSpatients were found to have a mutation in the seventh exon of the FALDH gene, the C943T mutation.This base pair substitution results in an amino acid change. Further mutations found in the remainingSwedish patients and in non-Swedish patients were four more amino acid changes, five mutationsresulting in a prematurely terminated protein and one combined deletion and insertion of bases,resulting in an insertion of six amino acids.

A boy with multiple anomalies, including severe mental retardation, stenosis of the left bronchi,hirsutism and epilepsy, was analysed for chromosomal rearrangements. His karyotype showed additionof chromosomal material on one of his chromosome 1. Using fluorescence in situ hybridisation (FISH)with a chromosome 1 specific probe it was demonstrated that the extra material originated fromchromosome 1. Cosmids distributed over the long arm of chromosome 1 were used as probes toidentify the duplicated regions. It was shown that the mutation giving the boy his phenotype was aduplication of the chromosome bands 1q31 -q41.

Background: Previous studies have shown that the neuropeptide calcitonin gene-related peptide (CGRP) have an influence on osteoclastic bone resorption and that CGRP and substance P (SP), both wellknown markers for sensory neurons, behave as growth factors.Materials and Methods: The ontogeny of the sensory nerves in the hindlimb skeleton of the rat was studied from gestational day (GD) 15 to neonatal day (ND) 24 by immunohistochemistry. Neurofilaments and nerve terminals were labelled with protein gene-product 9.5 (PGP 9.5) and synaptophycin (SYN) respectively.Results: PGP 9.5 appeared at GD 15 and SYN at GD 19, both in the perichondrial tissue of the long bones. One week later, at ND 4 nerve fibre, immunoreactive to PGP 9.5 and SYN were observed within the bone organ. Sensory nerves, indicated by CGRP and SP, were first discerned at GD 18-19 in the periosteal tissue of the diaphyseal and metaphseal regions and in the bone organ at ND 4. Approximately at ND 6, vascular as well as non-vascular nerves extended into the metaphyses and at ND 8 into the epiphyses, concomitant with the first signs of mineralization.Conclusions: The study shows that a functional sensory nerve supply of the developing bone organ occurs immediatly prior to partus, apparently parallel with an increasing mineralization. The combined findings may indicate a sensory influence on developmental processes in the skeleton

The environment provided by commonly used infant incubators, the effect of radiantheat and exposure to cold air on the exchange of water and heat between newborninfants and their environment, and the water loss through the skin of infants born at24-25 weeks of gestation were investigated. The evaporation of water from the skinwas measured by the gradient method. Respiratory water loss and oxygenconsumption was measured with a method for indirect calorimetry, equipped foranalysis of water vapour.

Incubators with double walls and with the flow of air from the incubators heatsource directed between those walls had more homogenous air and inner hoodsurface temperature distributions. Term newborn infants exposed to a reducedambient air temperature reacted with an increase in respiratory water loss andoxygen consumption and a decrease in peripheral skin blood flow and skintemperature before central body temperature was affected, indicating an increasednon-shivering thermogenesis. Term and preterm infants nursed under a radiantheater had a increased rate of evaporation of water from the skin, which is due to thedifference in ambient humidity, and not to an effect of the non-ionising radiation onthe permeability of the skin. Term and preterm infants nursed in an incubator with anadded radiant heat source reacted with increased skin temperature and reducedradiative heat loss. In preterm infants born at 24 and 25 weeks of gestation,transepidermal water loss was high during the first two days after birth and thendecreased at a slower rate than previously reported for a group of slightly lesspreterm infants.

Epidemics of a permanent, non-progressive spastic paraparesis with sudden onset hasbeen reported from several rural areas of sub-Saharan Africa. Studies in East Africasuggested an association with dietary cyanide intake from unprocessed cassava. InZaire the disease was attributed to an infectious cause as the cyanogenic glucosides inthe cassava consumed were known to be removed by traditional soaking. The aims ofthe thesis were to define the disease entity and elucidate its etiology. A communitybasedsurvey in rural Zaire identified 110 live and 24 dead cases among 6764inhabitants (16/1000). The clinical findings were identical to earlier studies and it wasdecided to name the disease konzo as in the first known report. Annual and monthlyincidence of konzo was associated with almost exclusive consumption of shortsoakedbitter cassava roots. The appearence of konzo coincided with the completionof a tarmac road from the capital, which turned cassava into the main cash crop, andinduced short-cuts in the processing. A processing experiment showed that flour fromshort-soaked roots was high in cyanogens. A higher cyanide intake in affectedcompared to un-affected populations was confirmed by much higher urinarythiocyanate levels, the main metabolite. A low urinary sulphate indicated lowavailability of sulphur, the substrate for detoxification. All three konzo patientsexamined at onset had blood cyanide levels above 4 Ilmolll, versus only 2 out of 23controls (p<O.Ol). This supports an etiological role for cyanide. An odds ratio of 11was found for short-soaking of cassava, in a multivariate logistic regression analysis ofa case referent study in Zaire, with a dose-response curve indicating higher risk ofkonzo with frequent consumption of short-soaked cassava. Serological investigationsof 33 cases in Zaire excluded retrovirus etiology for konzo. Konzo was also identifiedin low prevalence in the Central African Republic, again associated with consumptionof insufficiently processed cassava. Investigation in Sweden of two severely disabledTanzanian patients revealed normal magnetic resonance imaging but neurophysiologyshowed isolated upper motor neuron dysfunction. This is consistent with clinicalfindings and identifies konzo as a distinct disease entity. The evidence for anetiological role of high cyanide and low sulphur intake in konzo is now strongenough to urge for prevention by promotion of efficient processing of cassava roots.