PubMed Health⌕ Search

Biomedical subjects

K H Gustavson

Publications and source records attributed to K H Gustavson.

At least 55 records · Page 3Linked to original sources
PubMed1993

Detailed genetic mapping of the von Hippel-Lindau disease tumour suppressor gene.

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited familial cancer syndrome characterised by a predisposition to the development of retinal, cerebellar, and spinal haemangioblastomas, renal cell carcinoma, and phaeochromocytoma. The gene for VHL disease has been mapped to chromosome 3p25-p26 and flanking markers identified. We report the detailed genetic mapping of the VHL disease locus in 38 families. Significant linkage was detected between VHL disease and D3S601 (Zmax = 18.86 at theta = 0.0, CI 0.0-0.025), D3S18 (Zmax = 11.42 at theta = 0.03, CI 0.005-0.08), RAF1 (Zmax = 11.02 at theta = 0.04, CI 0.007-0.01), and D3S1250 (Zmax = 4.73 at theta = 0.05, CI 0.005-0.15). Multipoint linkage analysis mapped the VHL disease locus between D3S1250 and D3S18 close to D3S601. There was no evidence of locus heterogeneity. This study has (1) confirmed the tight linkage between VHL disease and D3S601, (2) identified D3S1250 as the first marker telomeric to RAF1 which maps centromeric to the VHL disease gene, and (3) narrowed the target region for isolation of the VHL disease gene by positional cloning techniques to a 4 cM interval between D3S1250 and D3S18. These findings will improve the clinical management of families with VHL disease by improving the accuracy of presymptomatic diagnosis using linked DNA markers, and will enhance progress towards isolating the VHL disease gene.

Chromosome Mapping↗
PubMed1993

Linkage mapping of a severe X-linked mental retardation syndrome.

A four-generation Swedish family with a new type of X-linked mental retardation syndrome was recently reported by Gustavson et al. The complex syndrome includes microcephaly, severe mental retardation, optical atrophy with decreased vision or blindness, severe hearing defect, characteristic facial features, spasticity, seizures, and restricted joint motility. The patients die during infancy or early in childhood. Twenty-one family members, including two affected males, were available for study. Linkage analysis was conducted in the family by using 11 RFLP markers and 10 VNTR markers spread along the X chromosome. A hypervariable short tandem repeat of DXS294 at Xq26 showed a peak two-point lod score of 3.35 at zero recombination fraction. Calculations using the same markers revealed a multipoint peak lod score of 3.65 at DXS294. Crossover events with the centromeric marker DXS424 and the telomeric marker DXS297 delimit a probable region for the gene localization. It is noteworthy that hte disease loci of two other syndromes with overlapping clinical manifestations recently were shown by Turner et al. and Pettigrew et al. to be linked to markers at Xq26.

Abnormalities, Multiple↗
PubMed1992

Infantile autism--fragile X: molecular findings support genetic heterogeneity.

Twenty-two members of 18 families with autism have been examined for the presence of mutations and abnormal methylation in the FMR-1 region at Xq27.3. All patients fulfilled diagnostic criteria of infantile autism. A characteristic pattern of insertion and methylation were detected after Southern blot analysis in 7 autistic individuals expressing the fragile site at Xq27.3. Normal DNA patterns were observed in 15 autistic boys cytogenetically negative for the fragile site. The results indicate a lack of involvement of the FMR-1 region in infantile autists negative for fragile X expression.

Adolescent↗
PubMed1992

Mutation analysis for prenatal diagnosis and heterozygote detection of Gaucher disease type III (Norrbottnian type).

A single base substitution in exon 10 of the glucocerebrosidase gene was detected in families affected by Gaucher disease (GD) type III. This mutation, which results in the substitution of proline for leucine in position 444 of glucocerebrosidase, has been shown to result in type III GD in a Swedish population. Three fetuses at risk for GD type III were diagnosed as homozygous for the mutation and the pregnancies were terminated. In a fourth pregnancy, one parent was excluded as being a carrier and the risk of having a child affected by GD was ignored. Direct analysis of common mutations causal to GD is now available and improves prenatal diagnosis in families where the molecular defect has been characterized.

Base Sequence↗
PubMed1992

Molecular analysis of patients with Hunter syndrome: implication of a region prone to structural alterations within the IDS gene.

Hunter syndrome or mucopolysaccharidoses type II (MPS-II), is a lysosomal storage disorder caused by a deficiency in the activity of the enzyme iduronate-2-sulphatase (IDS). We have investigated the occurrence of rearrangements and deletions of the IDS gene in a Southern analysis of 46 unrelated MPS-II patients of different ethnic origins using a cDNA clone containing the entire IDS gene as a probe. Structural alterations of the IDS gene were found in DNA from 9 patients two of whom showed large deletions including all coding sequences of the gene. The distal and proximal breakpoint of these deletions were determined by hybridization of markers flanking the IDS gene. Seven of the observed alterations constitute major rearrangements of the gene. Interestingly, six of these rearrangements showed similar or identical patterns by Southern analysis suggestive for a region prone to structural alterations within the IDS gene. We also demonstrate the potential use of the IDS probe for carrier detection in families with a rearranged IDS gene. A contiguous gene deletion syndrome characterized by Hunter syndrome and epilepsy is also discussed.

Blotting, Southern↗
PubMed1992

The gene for Best's macular dystrophy is located at 11q13 in a Swedish family.

A large Swedish family with more than 250 cases of Best's macular dystrophy has been clinically and genetically studied. The gene was traced to a couple born in central Sweden in the 17th century. Highly significant evidence for genetic linkage to DNA markers on chromosome 11q13 was detected. A lod score of 15.12 was obtained at recombination fraction 0.01 with DNA marker INT2 (also called FGF3). The retinally expressed gene ROM1, which maps to the same chromosomal region is a candidate for this genetic disease.

Chromosomes, Human, Pair 11↗
PubMed1992

Congenital glaucoma resulting from a chromosomal translocation.

A boy with congenital glaucoma, mental retardation and dysmorphic features is described. Chromosome analyses revealed two different, apparently balanced translocations; between the long arms of chromosomes 2 and 10 as well as between the long arms of chromosomes 8 and 12; 46,XY t(2;10)(q33;q26)pat, t(8;12) (q24;q21). The healthy father of the patient had the same balanced translocation between the long arms of chromosomes 2 and 10; 46,XY, t(2;10)(q33;q26).

Chromosome Banding↗
PubMed1992

Chromosomal aberrations in a patient with severe psychopathology.

The case of a female patient showing aggressive, compulsive, destructive behaviour, ritualistic faecal smearing, and hyperactivity is presented. The behaviour is long standing, therapy-resistant, and its aetiology is unknown, although it is seemingly associated with chromosomal abnormalities secondary to abnormal plasma factors.

Abnormalities, Multiple↗
PubMed1991

Early prenatal diagnosis of the fragile site at Xq27.3 associated with Martin-Bell syndrome.

Early prenatal diagnosis of the fragile X was attempted in 44 pregnancies, including one twin pregnancy at risk of Martin-Bell (MB) syndrome. The sex ratio was 24M:21F. The fragile site was reproducibly demonstrated in cultured chorionic villus (CV) cells in eight male and five female fetuses. Six of the male and three of the female fetuses were terminated. Simultaneous RFLP analysis provided confirmative data with flanking DNA markers in 3 of 13 analysed cases. Recombination and/or non-informativeness at available distal and/or proximal loci were found in nine cases. In one male fetus, discordance between the haplotype and cytogenetics (fragile-X-negative) suggested the presence of a normal male transmitter, a double meiotic cross-over within the region, or a false-negative cytogenetic diagnosis. However, discordance between prenatal and post-termination/postnatal cytogenetic findings was not observed in this series. The use of excess thymidine for induction of the fragile X in cultured CV cells provided in the majority of cases a safe and rapid method for cytogenetic diagnosis, with options for early induced termination in fragile-X-positive pregnancies, for simultaneous RFLP analysis, and for subsequent second-trimester analysis of fetal blood in complicated cases.

Adolescent↗
PubMed1991

Evaluation of DNA-based diagnosis for haemophilia A.

Haemophilia A is an X-linked disorder affecting 1.7/10,000 males. Carrier detection in females and prenatal diagnosis of male foetuses is greatly improved by DNA-based diagnosis. This study describes the use of the polymerase chain reaction (PCR) and allele-specific oligonucleotides (ASO) in a clinical study comprising 190 individuals in 27 families. Prenatal diagnosis was performed in eight cases. Of three male fetuses, two were found to be affected and one unaffected. It is shown that 62% of women in the Swedish population are heterozygous for the intragenic BclI or XbaI polymorphisms and consequently a majority of them (53%) can be analysed in the PCR-based format. Using three intragenic polymorphisms, a combined heterozygosity of 64% was recorded in the females. If the extragenic loci DXS52 and DXS15 were used in addition, 97% of the women could be counselled by DNA-analysis. Our study demonstrates the usefulness of PCR-based analysis of the BclI- and the XbaI-polymorphisms in genetic counselling. The counselling of women with conflicting results between coagulation data and DNA-based linkage analysis is discussed.

Alleles↗
PubMed1991

Low concentrations of sodium and magnesium in erythrocytes from cystic fibrosis heterozygotes.

The concentrations of electrolytes and trace elements in erythrocytes were determined in eight children with cystic fibrosis (CF) and the parents of four of the children and compared with age- and sex-matched healthy controls. The children with CF had significantly lower median erythrocyte concentrations of sodium, magnesium and zinc and a higher median concentration of calcium than both the healthy control children and the parents of the CF children. Although the sodium and magnesium median values were higher in CF parents than in CF children they were nevertheless significantly lower than in adult controls. These data indicate a system for heterozygote detection.

Adolescent↗
PubMed1990

Growth retardation in Down syndrome in relation to insulin-like growth factors and growth hormone.

Growth retardation is a cardinal characteristic of Down syndrome (DS). It is most pronounced from the age of 6 months, when growth starts to become growth hormone (GH) regulated. DS children have normal serum levels of GH. GH regulates the production of insulin-like growth factors (IGFs), which act as growth hormones. Therefore, the serum IGF pattern and the levels of their receptors were studied in fetuses with trisomy 21 and in patients with DS throughout life. Serum levels of IGF were determined by radioimmunoassays for insulin-like growth factors 1 and 2 (RIA-IGF-1 and RIA-IGF-2) showing normal serum RIA-IGF-2 levels throughout life. However, serum RIA-IGF-1 did not rise during childhood and remained at a low level throughout life. Determination of serum IGF by a radioreceptor assay (RRA-IGF), which detects both IGF-1 and IGF-2 as well as enhanced activity in the fetal circulation, showed a deficit in serum RRA-IGF in fetuses with trisomy 21, but at birth and throughout life elevated serum RRA-IGF levels. In spite of this, no differences were observed in fetal brain or liver binding sites for IGF-1, IGF-2, or insulin. Since in the RRA-IGF method IGF-1, IGF-2, and a fetal form of IGF-1 cross-react, it is possible that there is a delayed maturation with incomplete switching from production of the fetal form of IGF to production of the GH-regulated IGF-1 in DS. The deficit in IGF-1-like peptides might account for the growth retardation in DS. In order to study the effect of human growth hormone (hGH) therapy in DS, 5 growth-retarded children with DS were treated with hGH for 6 months. During this period the growth velocity doubled and the serum IGF-1 levels were restored to normal. Thus, DS children respond to hGH treatment.

Adult↗