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Biomedical subjects

G Annerén

Publications and source records attributed to G Annerén.

At least 73 records · Page 4Linked to original sources

Abnormal serum IgG subclass pattern in children with Down's syndrome.

Susceptibility to infections is a well known feature of Down's syndrome. The possible relation between this predisposition and the serum concentrations of the IgG subclasses was studied in 38 children with Down's syndrome aged 1-12 years. An age matched group of 50 healthy children served as controls. The serum concentrations of IgG1 and IgG3 were significantly raised among children with Down's syndrome in all three age groups studied (that is 1-2.5, 4-8, and 9-12 years). The serum concentrations of IgG2 were normal in the first two groups but significantly reduced in the third age group. In contrast, the concentrations of IgG4 among children with Down's syndrome were significantly reduced in all three age groups. Moreover, among the children with Down's syndrome aged 4-12 years 68% (15/22) had IgG4 concentrations below 2 SDs of the geometrical mean of the controls. The results may partially explain the proneness of children with Down's syndrome to infections with encapsulated bacteria. Although the underlying cause of these abnormalities is unknown, IgG subclass determination seems relevant in the clinical evaluation of children with Down's syndrome.

Age Factors↗

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), an autosomal recessive disorder: clinical reports and review of the literature.

We present 2 new patients with the megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), review the literature, and discuss the prenatal diagnosis and treatment. MMIHS, as reported in 43 cases, is usually lethal. Most children die during the first year of life, and only 3 children survived their first year. We report the 6th pair of sibs with the disease. Overall, 17 patients reported have had sibs with MMIHS or the parents were consanguineous; 4 times the parents were first, cousins, confirming that this is an autosomal recessive disorder. The present 2 children, whose parents also were first cousins, were of different sex. They had typical MMIHS with abdominal distension due to pronounced megacystis, hydronephrosis, microcolon, and microileum, involving the distal part of the ileum, malrotation of the gut, and intestinal hypoperistalsis. Neither surgery nor medical treatment was successful and the children died at the age of 19 days and 2 1/2 months, respectively. There is no cure for the disease. However, a new protkinetic drug, Cisapride might be worth trying in these cases. Prenatal ultrasound diagnosis of MMIHS might be possible.

Abnormalities, Multiple↗

Ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC): the clinical variation and prenatal diagnosis.

Six patients with the ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, namely five members of the same family and one sporadic case, are presented. One of the main features of the EEC syndrome, ectrodactyly, was missing in five of the patients. The diagnosis did not become clear until the youngest son of the family was born. All of our six patients had a low birth weight and some were born preterm, and four had poly- and/or syndactyly without ectrodactyly. A low birth weight and polysyndactyly have been reported previously in patients with the EEC syndrome and might be features of the syndrome. The present patients illustrate the great phenotypic variability in the EEC syndrome and the need for a careful search for microsymptoms in potential gene-carriers. In two members of the affected family, EEC syndrome was diagnosed prenatally after 16 weeks of gestation by detection of the cleft lip and palate on ultrasound examination. The mother chose to continue the pregnancies. However, prenatal diagnosis of cleft lip and palate might be of value in genetic counselling for other inherited syndromes leading to severe disability.

Adult↗

Lowe's oculocerebrorenal syndrome--variation in lens changes in the carrier state.

The lens changes in DNA based analysis compatible carriers of the gene of Lowe's syndrome in one family are described. The lens changes consist of a large amount of characteristic punctate cortical opacities. In two of the three carriers, formed lens opacities were found, appearing like congenital riders. In one lens containing congenital-like riders a posterior subcapsular cataract had developed. In comparison with a previously examined family, the lens changes in the present family were overall much more extensive. It appears there is a variation in expressivity of the gene in carriers of different families.

Adult↗

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↗

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↗

Increase in serum concentrations of IgG2 and IgG4 by selenium supplementation in children with Down's syndrome.

In a previous study on children with Down's syndrome a reduced rate of infections was reported by their parents after the children had received six months' treatment with selenium supplements. In the present study the concentrations of the four IgG subclasses were measured in 29 of these children in samples of serum obtained before and immediately after the period of supplementation and one year after it had finished. Selenium had a significant augmentative effect on the serum concentrations of IgG2 and IgG4, but not of IgG1 and IgG3. This effect was not related to age, as among children over the age of 6 years the serum concentrations of IgG2 and IgG4 had decreased significantly one year after the treatment had been stopped. This study suggests that selenium has an immunoregulatory effect, which might be of importance in both basic research and clinical practice.

Adolescent↗

PC-based system for classifying dysmorphic syndromes in children.

A system is described running on any IBM-compatible personal computer operating under MS-DOS which permits an expert in pediatric dysmorphology to formulate dysmorphic features and syndromes in a knowledge base, and a user to enter, analyze, store and retrieve case data. For each case, the system calculates the Bayesian probability of the presence of each syndrome in the knowledge base and lists as the differential diagnosis those syndrome whose probability exceeds 90%. For explanatory purposes, the syndrome definitions can be displayed and compared to the case data. The system has been tested and used in the Department of Clinical Genetics at Uppsala University Hospital. The current scope of the system's knowledge was found to be of valuable assistance to the pediatric practitioner but it must be expanded and refined for use by a clinical geneticist. This study has shown the validity of the system's design and structure and further work is under way to extend its knowledge capability.

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↗

DiGeorge syndrome in a child with partial monosomy of chromosome 22.

A girl with severe neonatal hypocalcaemia, thymic hypoplasia, congenital heart disease and mental retardation in combination with a partial monosomy of chromosome 22, del(22)(pter-q11.3), is reported. Nine other patients with an association between partial monosomy 22 and a DiGeorge syndrome have been reported earlier, and this combination probably constitutes a deletion syndrome similar to the Prader-Willi and the aniridia-Wilms' tumour syndromes. However, the deletion of chromosome 22 is mostly due to a translocation, with trisomy for another chromosomal segment. Such a mechanism may explain the different clinical features seen in patients with partial monosomy 22. In the present case there was an unbalanced translocation with a probable trisomy of the short arm of chromosome 20 combined with the partial monosomy 22. Cytogenetic investigation with high resolution banding techniques is indicated in patients with thymic aplasia and suspected DiGeorge syndrome.

Chromosome Deletion↗

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↗

Lowe oculocerebrorenal syndrome: DNA-based linkage of the gene to Xq24-q26, using tightly linked flanking markers and the correlation to lens examination in carrier diagnosis.

The Lowe syndrome (LS), or oculocerebrorenal syndrome, has been studied using DNA-based linkage analysis, and the findings have been correlated with the result of a thorough ophthalmologic examination. It was found that the LS gene was linked to markers in the Xq24-q26 region and that the locus DXS42 was the most closely linked marker, giving a LOD score of 3.12 at zero recombination distance. Combined with earlier data, this forms the basis for carrier detection and prenatal diagnosis by using tightly linked flanking markers. A summary of our and other data suggests that the loci DXS17, DXS11, DXS87, and DXS42 are located on the proximal side, and DXS86 and DXS10 on the distal side of the Lowe locus. In isolated cases of LS the question of whether the mother is a carrier of the mutation arises. It was found that a lens examination with slit-lamp illumination and a count of the total number of lenticular opacities is a reliable method of ascertaining the carrier state.

DNA Probes↗