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Biomedical subjects

K H Gustavson

Publications and source records attributed to K H Gustavson.

At least 37 records · Page 2Linked to original sources

Achondroplasia in Sweden caused by the G1138A mutation in FGFR3.

Achondroplasia, an autosomal dominant inherited disorder, is one of the most common forms of skeletal dysplasia resulting in disproportionate extreme shortness. Recently, two point mutations, both affecting nucleotide 1138 in the fibroblast growth factor receptor type 3 (FGFR3) gene, were found to be the cause of the disorder. We investigated DNA from 16 Swedish patients with achondroplasia for the presence of these mutations. All patients were found to be heterozygous for the G to A transition at nucleotide 1138. Our data thus support previous reports showing a striking genetic homogeneity, in that almost all achondroplasia patients have the FGFR3 G380R mutation at the protein level.

Achondroplasia↗

Hyperkalemic periodic paralysis caused by recurring mutation in the adult muscle sodium channel alpha-subunit gene.

Linkage studies and mutation analysis were performed in two Swedish families with hyperkalemic periodic paralysis (HYPP), an autosomal dominant inherited disorder characterized by episodic muscle weakness associated with increasing or high levels of serum potassium. The gene for HYPP is the gene encoding the alpha-subunit of the sodium channel of adult human skeletal muscle (SCN4A). SCN4A has been localized on chromosome 17 q closely linked to the human growth hormone gene. Linkage between a microsatellite polymorphism in the SCN4A gene and the disease was shown in two Swedish families (Z = 12.10 theta = 0). Sequence analysis revealed that the two Swedish families have got a C to T transition at position 2188 in the cDNA. At the protein level this Thr 704 to Met mutation is located in the fifth membrane spanning segment of domain II of the protein, as previously described (28). The mutation was linked to different microsatellite alleles regarding both a (GT)n and a (GA)n repeat in the gene. Either the families are related and new mutations have occurred in both microsatellites when the pedigrees were separated or the mutation has arisen independently in the two families analysed. From the mutant alleles characterized so far it seems as if a limited number of mutations is present in this gene.

Adult↗

Autosomal dominant cerebellar ataxia deafness and narcolepsy.

A new autosomal dominant syndrome in a Swedish pedigree is described. Five patients were affected with cerebellar ataxia and sensorineural deafness. Four of these patients had symptoms of narcolepsy. Optic atrophy, other neurological abnormalities and psychiatric symptoms developed with increasing disease duration. Three patients had non-neurological disease in addition, including diabetes mellitus in two and hypertrophic cardiomyopathy in one. Autopsy with neuropathological examination was performed in one case. Molecular studies focused on the short arm of chromosome 6, including the HLA DR2 locus associated with narcolepsy and the (CAG)n repeat at the spinocerebellar ataxia type 1 (SCA1) locus. Biochemical investigation of muscle biopsy of one case indicated mitochondrial dysfunction with selective decrease in ATP production for substrates that normally give the highest rates. The activity of glutamate dehydrogenase was reduced, indicating a low mitochondrial density. We postulate an autosomal dominant genetic factor responsible for this syndrome. Linkage was excluded to HLA DR2, and a normal sized SCA1 repeat was observed. We conclude that a locus predisposing to ataxia, deafness and narcolepsy exists outside this region of chromosome 6.

Adolescent↗

Severe mental retardation in 2 to 24-month-old children in Lahore, Pakistan: a prospective cohort study.

Severe mental retardation (developmental quotient (DQ) < 50) was investigated in 1303 children from 2 to 24 months of age, born during 1984-87 in four population groups representing different socio-economic levels in and around Lahore, Pakistan. The incidence per 1000 live births was 22 in the periurban slum, 9 in the urban slum, 7 in the village and 4 in the upper middle class group. The aetiology was prenatal in 79%, perinatal in 14% and untraceable in 7% of cases. Down's syndrome was the most common cause of severe mental retardation (36%). Impairments were studied at 2 years of age. Impairment of language was present in all, while locomotor dysfunction was seen in 89% of cases. Epilepsy and cerebral palsy were each present in 22% of cases. Mortality among these severely mentally retarded children was 36%.

Asphyxia Neonatorum↗

Fluorescent detection of microsatellite polymorphisms: properdin deficiency linked to PFC microsatellite.

Microsatellite polymorphisms are widely used to map the genes responsible for inherited disorders. The most commonly used detection is based on radioactive labelling and autoradiography. We now present the successful detection of fluorescence-labelled allelic fragments on an automated DNA sequencer. This allows for safer and quicker detection as well as a potential for more efficient processing of the data, e.g. for linkage analysis. The system was tested in the mapping of properdin deficiency, an X-linked condition with increased risk for a severe infection in the affected.

DNA, Satellite↗

Fine mapping of the congenital chloride diarrhea gene by linkage disequilibrium.

Congenital chloride diarrhea is a recessively inherited intestinal disorder affecting electrolyte transportation. The clinical presentation is a life-threatening watery diarrhea with a high chloride content. Recently, the congenital chloride diarrhea gene (CLD) was assigned to chromosome 7 by linkage in eight Finnish families. In the present study, refined mapping of CLD was performed by studying linkage and linkage disequilibrium in 24 Finnish and 4 Swedish families. Recombination mapping assigned CLD to an approximately 10-cM region flanked by D7S515 and D7S799. Linkage disequilibrium was detected over this large genetic region, with the strongest allelic association at D7S496. Application of the Luria and Delbrück-derived analysis allowed for a further narrowing of the CLD region to approximately 0.37 cM from the marker D7S496. Haplotype analysis placed CLD unequivocally between D7S501 and D7S692, very close to D7S496 and most likely on the distal side of D7S496. This combined analytical approach allowed highly accurate mapping of CLD, each component adding complementary and consistent mapping information.

Child↗

Fine mapping of Best's macular dystrophy localizes the gene in close proximity to but distinct from the D11S480/ROM1 loci.

The Best's macular dystrophy (BMD) gene has previously been mapped to the 11q13 region. In this study, recombination data localizes the BMD gene to the 6-cM genetic interval between the markers Fc epsilon RI and D11S480/ROM1 in a large Swedish 12-generation BMD family. Mutation analyses of the candidate gene ROM1 did not reveal any mutations that could explain the disease phenotype. However, one recombination event between intragenic ROM1 polymorphisms and the BMD phenotype was detected. Therefore, it is highly unlikely that mutations in the ROM1 gene cause BMD. Identification of the disease gene will elucidate the pathophysiological mechanism in BMD, which may also be of importance in other retinopathies such as age-related macular degeneration.

Alleles↗

The Sjögren-Larsson syndrome gene is close to D17S805 as determined by linkage analysis and allelic association.

Sjögren-Larsson Syndrome (SLS) is characterized by congenital ichthyosis, spastic dior tetraplegia and mental retardation. It is an autosomal recessive trait that is frequent in the northern part of Sweden. Based on linkage analysis and allelic association, the disorder has now been mapped to chromosome 17. Meiotic recombinations suggest that the gene is flanked by D17S805 on the centromeric and D17S783, D17S959, D17S842 and D17S925 on the telomeric side. These markers map to the same location in reference pedigrees. Strong allelic association (chi-square 60.28, p < 0.0003) to D17S805 suggests that the mutation is located close to this marker.

Alleles↗

Birth defects surveillance: Jefferson County, Alabama, and Uppsala County, Sweden.

Birth defects in live-born infants were documented for 2 years in Jefferson County, Alabama (USA)--1986 and 1987--and in Uppsala County, Sweden--1985 and 1986. A total of 27,561 live births (9,179 white male, 8,728 white female, 4,883 black male, and 4,771 black female infants) occurred in Jefferson County; 6,896 live births (3,535 male and 3,361 female) were recorded in Uppsala County. These newborns were studied to establish a database of birth defects for the two small geographic areas and to study similarities and differences. Rates of hip dislocation, heart malformations, and clubfoot were high in Swedish infants. Similar frequencies of spina bifida and polydactyly were noted in Alabama whites and Swedish infants. Regional registries offer a systematic approach to detection of clustering of specific birth defects, identification of families for further study, location of patients with unique needs, and enhanced coordination of health services, including genetic counseling.

Alabama↗

Strong founder effect for the fragile X syndrome in Sweden.

We analyzed the FRAXAC2 and DXS548 microsatellites in normal and fragile X chromosomes from Sweden and the Czech Republic in order to investigate a possible founder effect for chromosomes carrying a fragile X mutation. We report a much stronger linkage disequilibrium between the marker haplotypes and the disease in Swedish fragile X chromosomes than in Czech and most other previously studied Caucasian populations. Two haplotypes accounted for 64% of Swedish fragile X chromosomes and for only 14% of normal chromosomes. Neither of these two haplotypes was found in Czech chromosomes, but the most common Swedish fragile X haplotype is the same as that reported to be predominant in Finnish fragile X patients. Linkage disequilibrium was observed in the Czech fragile X chromosomes but the haplotypes were more diverse and similar to those observed in other Caucasian populations. The most prevalent Swedish fragile X haplotype was traced back from affected males to common ancestors in the early 18th century. This indicates an apparently silent segregation of fragile X alleles through up to nine generations. The geographical distribution of the two major at-risk haplotypes in Sweden suggests that they were present among early settlers in different parts of the country.

Chi-Square Distribution↗

Dermatoglyphics in individuals with asocial behaviour.

The patterns of fingertip prints (dermatoglyphics) in Swedish series of sexual offenders of law compared with common offenders of law and normal individuals were analysed. The dermatoglyphic patterns in common offenders of law did not differ from those in normal individuals. The group of sexual offenders of law showed statistically significant differences (p < 0.001) in the dermatoglyphic patterns compared to the samples of common criminals and normals.

Crime↗

New X-linked syndrome with severe mental retardation, severely impaired vision, severe hearing defect, epileptic seizures, spasticity, restricted joint mobility, and early death.

A family with an X-linked mental retardation syndrome involving seven children in two generations is reported. The syndrome includes microcephaly, severe mental retardation, optic atrophy with severely impaired vision or blindness, a severe hearing defect, spasticity, epileptic seizures, restricted movement of the large joints, and death in infancy or early childhood. We conclude that this is a distinct, previously unrecognized X-linked mental retardation syndrome.

Abnormalities, Multiple↗

Early child health in Lahore, Pakistan: II. Inbreeding.

The prevalence of consanguineous marriages was studied in 940 families belonging to four different socio-economic groups in and around Lahore, Pakistan. The births occurring in these families from September 1984 to March 1987 were also investigated for birth defects. The overall prevalence of consanguineous marriages was 46%. The first cousin marriages were most common (67%), followed by the marriages between second cousins, 19%. The prevalence of consanguineous marriages was clearly associated with the socio-economic status of the study groups; 50% of the marriages was related in the periurban slum, 49% in the village, 44% in the urban slum and 31% in the upper middle class. The birth defects were also more prevalent in the poorer areas, being highest in the periurban slum (17.7%) followed by the urban slum (15.6%) and then the village (14.8%) and lowest in the upper middle class (12.3%). Although, the frequency of both consanguinity and birth defects were related with the socio-economic levels of the study groups, there was no association between inbreeding and birth defects. Perhaps, deleterious recessive genes for birth defects have been "bred out", because of continuous inbreeding over generations in this population. There was a significant predilection of major birth defects in boys without clear sex linkage. The conclusion is that the rate of consanguineous marriages was high, especially in the poorer areas, but the relationship between consanguineous marriages and birth defects was little or none. However, other child health indicators may be affected by consanguineous marriages.

Adult↗