PubMed Health⌕ Search

Biomedical subjects

K H Gustavson

Publications and source records attributed to K H Gustavson.

At least 73 records · Page 4Linked to original sources

Benign ovarian teratomas. An analysis of their cellular origin.

To determine the cellular origin of benign ovarian teratomas with a 46,XX chromosome constitution, DNA markers recognizing restriction fragment length polymorphisms (RFLPs) were hybridized to DNA from six teratomas and their hosts. DNA markers heterozygous in the host were completely heterozygous in two of the teratomas. The remaining four showed a mixture of homozygosity and heterozygosity. These results suggests that most of the analyzed benign ovarian teratomas arose from germ cells after the first meiotic division by failure of meiosis II. Teratomas heterozygous for all tested markers may arise from failure of meiosis I. In addition, 21 cases were karyotyped and analyzed for centromeric chromosome markers to study the mechanism by which they were generated. Three of these tumors were homozygous when the host was heterozygous and therefore resulted from a failure of meiosis II or duplication of a mature ovum. Three cases were heterozygous for the centromeric chromosomal marker like the host and therefore probably originate from a premeiotic cell or a cell in which meiosis I has failed. One ovarian teratoma had an aberrant karyotype 47,XX,+8.

Alleles↗

X-linked myotubular myopathy: a linkage study.

Two families with the congenital X-linked infantile form of myotubular myopathy have been investigated by linkage analysis using markers from the X-chromosome. Linkage was found at the locus Xq28 (with DXS52). The analysis gave a peak lod score of 2.41 at the recombination fraction zero. Free recombinations (theta = 0.50) were seen using the markers DXS84, DXS14 and DXS146 from the p arm of the X-chromosome. Since the disorder is very rare, it is important to add cumulative linkage data from the few families that do exist.

Female↗

Abnormalities of the cerebellum in oro-facio-digital syndrome II (Mohr syndrome).

Two patients with oro-facio-digital syndrome type II (OFD-II, Mohr syndrome) with associated cerebellar atrophy are described. Three other cases of the Mohr syndrome with cerebellar abnormalities are cited from the literature. Cerebellar involvement seems to be a clinical feature of this syndrome. Unfortunately, there is a lack of CNS reports for many of the previously described patients. In all cases with this entity, careful neurological and radiological examinations of the cerebellum are recommended.

Abnormalities, Multiple↗

Severe mental retardation in Jordanian children. A retrospective study.

The etiology of severe mental retardation has not previously been studied in Jordan. In a group of 203 mainly severely mentally retarded children born 1975-1985, we found the etiology to be related to two main factors: (1) sequele from high perinatal morbidity or meningitis in infancy leading to a combination of severe mental retardation and cerebral palsy; (2) a high degree of intermarriage and a high frequency of retarded siblings indicating that genetic causes of MR are common. The results underscore the importance of further development of antenatal and perinatal care, especially for poor people and the need of genetic counselling.

Child↗

Isolation of a DNA probe of potential use for diagnosis of the fragile-X syndrome.

A new cloned DNA probe (U6.2), which recognizes polymorphisms near the locus for the fragile-X syndrome, was isolated. No recombinations were observed between the probe and the disease locus, although recombinations were observed with several other probes known to be located close to the fragile site. The locus defined by the probe, DXS304, cosegregated with the fragile-X phenotype in 29 informative meioses (zeta = 4.97, tau = 0.00). The degree of polymorphism at this locus and its proximity to the fragile-X locus makes it useful for carrier diagnosis and as a new starting point for attempts to clone the gene responsible for the disease.

DNA Probes↗

The prevention and management of autosomal recessive conditions. Main example: alpha 1-antitrypsin deficiency.

In populations in which a particular autosomal recessive disorder is treatable and relatively common, and for which there is a simple diagnostic test, newborns can be screened and treated. For some disorders, such as alpha 1-AT, young people can be screened and given appropriate advice to ameliorate the future symptoms. For some severe common and non-treatable autosomal recessive disorders, for example cystic fibrosis, carrier tests will probably soon be available for population screening of young people. Couples found to be carriers can then be offered prenatal diagnosis and termination of the pregnancy, if the fetus is affected. In the not-too-distant future the approaches will hopefully be treatment and correction of these disorders in the affected fetus or newborn.

Genes, Recessive↗

Hereditary spastic diplegia with mental retardation in two young siblings.

Two young siblings with hereditary spastic diplegia and mental retardation (Böök's syndrome) have had detailed clinical investigations since infancy. The inheritance pattern of this syndrome in the present family fits well with an autosomal recessive trait--with affected sibs of opposite sex, born to consanguineous healthy parents.

Abnormalities, Multiple↗

Increased plasma and erythrocyte selenium concentrations but decreased erythrocyte glutathione peroxidase activity after selenium supplementation in children with Down syndrome.

An investigation was made of the activity of glutathione peroxidase (GSH-Px) in erythrocytes and the levels of selenium in plasma and erythrocytes before, during and after selenium supplementation in children with Down syndrome (DS). This subject is of interest since it has been suggested that selenium supplementation could enhance the GSH-Px activity in erythrocytes, probably leading to improved protection against oxygen radicals, which might cause damage by lipid peroxidation, especially in the brain. Forty-eight children with DS were treated with selenium-rich yeast tablets (10 micrograms/kg body weight/day) for 6 months. The supplementation was well tolerated and no side effects were observed. Selenium supplementation resulted in increased concentrations of selenium both in plasma and erythrocytes, but decreased GSH-Px-activity in erythrocytes. Plasma and erythrocyte selenium levels but almost regained the initial values 12 months after termination of the supplementation. Erythrocyte GSH-Px activity, on the other hand, remained reduced and did not return to the presupplementation levels. Until we gain more knowledge about the biological functions of selenium in man and the role of oxygen metabolism in the development of presenile dementia in DS, universal selenium supplementation in DS patients cannot be recommended.

Adolescent↗

Linkage analysis of families with fragile-X mental retardation, using a novel RFLP marker (DXS 304).

A new polymorphic DNA marker U6.2, defining the locus DXS304, was recently isolated and mapped to the Xq27 region of the X chromosome. In the previous communication we describe a linkage study encompassing 16 fragile-X families and using U6.2 and five previously described polymorphic markers at Xq26-q28. One recombination event was observed between DXS304 and the fragile-X locus in 36 informative meioses. Combined with information from other reports, our results suggest the following order of the examined loci on Xq: cen-F9-DXS105-DXS98-FRAXA-DXS304-(DXS52-F8 -DXS15). The locus DXS304 is closely linked to FRAXA, giving a peak lod score of 5.86 at a corresponding recombination fraction of .00. On the basis of the present results, it is apparent that U6.2 is a useful probe for carrier and prenatal diagnosis in fragile-X families.

Chromosome Mapping↗

A new type of muscular dystrophy in two brothers: analysis by use of DNA probes suggests autosomal recessive inheritance.

X-chromosome-specific DNA probes were used to study a new type of muscular dystrophy (MD) presented by two boys in a family in which there was no previous history neuromuscular disease. Clinical investigations showed evidence of myogenic myopathyia, but its exact nature could not be established. The results of the DNA analysis exclude DMD, BMD and EMD. We suggest a probable autosomal recessive inheritance for the MD seen in this family.

Adolescent↗

Probable homozygotic form of the Marfan syndrome in a newborn child.

A case of Marfan's syndrome diagnosed in a newborn boy is described. Both parents were affected by the disease but none of them was aware of it. The boy had cardiac, skeletal and ocular manifestations from birth. He suffered early from severe congestive heart failure due to mitral insufficiency and died at four months of age of pneumonia. The family history is described in this report.

Adult↗

A case of complete trisomy 2p/triploidy mosaicism.

This report describes a newborn male infant with complete trisomy 2p in 80% and triploidy in 20% of cultured cells from peripheral blood. The boy was delivered by Caesarean section after 32 weeks of gestation because of signs of intrauterine asphyxia. The infant, who was utterly small for his gestational age, showed an aberrant motoric pattern and a high forehead, low-set ears, a prominent occiput and scoliosis, an extension defect in the knee joints and flexed, ulnar-deviated wrists. He had flexed thumbs, sandal gap bilaterally and syndactyly between toes III and IV bilaterally. Autopsy revealed multiple internal malformations.

Abnormalities, Multiple↗