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A V Thornórsson

Publications and source records attributed to A V Thornórsson.

6 recordsLinked to original sources
PubMed2001

[A mutation detection in a transcription factor for adipocyte development in children with severe obesity.].

OBJECTIVE: A substantial proportion of human obesity may be explained by genetic variability. Researchers have tried to identify the important genes in obesity with little sucsess. PPARg2 (peroxisome proliferator activated receptor g 2) is a transcription factor of the nuclear hormone receptor superfamily. It plays a key role in the developement and differentiation of adipocytes. Recently the mutation Pro115Gln in the PPARg2 gene was identified and shown to have a significant correlation with severe obesity. The actual prevalence and distribution of this mutation is not known. The aim of this study was to look for this mutation among Icelandic children suffering from severe obesity. MATERIAL AND METHODS: Thirty-five children and adolescents, aged 4-18, who have been diagnosed with severe obesity participated in the study. Eight parents and siblings aged 19-41 also participated. All study subjects had been obese since early childhood. Body mass index (BMI) was used to describe the phenotype of the subjects. The participants had a BMI of 28.0 to 52.2 kg/m(2). Genomic DNA was extracted from leucocytes. A 131 bp segment was amplified using polymerase chain reaction. The amplified product was digested with the restriction enzyme Hinc II, resolved on agarose gel and visualized under ultraviolet illumination after staining with ethidium bromide. To examine other mutations on the same 131 bp segment enzymatic mutation detection (EMD) was used. Finally the segments giving variable results using EMD were sequenced using the classic Sanger s method. RESULTS: The mutation Pro115Gln was not found in any of the specimens after analysis of the restriction fragment length polymorphism. The results of EMD indicated mutations or polymorphisms in three of the subjects but DNA sequencing failed to confirm these results. CONCLUSIONS: The mutation Pro115Gln or other genetic alternations within the exon examined do not appear to have a significant role in severe early - onset obesity in Icelandic children.

English Abstract↗
PubMed2000

[Complete androgen insensitivity in an Icelandic family caused by mutation in the steroid binding region of the androgen receptor.].

INTRODUCTION: Androgen insensitivity syndrome (AIS) is a X-linked rescessive disorder characterized by impairment of the androgen-dependant male sexual differentiation. The cause of AIS is in most cases a mutation in the gene of the androgen receptor on the X chromosome. In this study we describe an Icelandic family with two girls with AIS. A search for mutations in the androgen receptor gene was performed in order to identify the genetical and molecular basis for AIS in this family. MATERIAL AND METHODS: Genomic DNA was isolated from two girls with complete AIS and their close relatives. PCR was used to amplify all eight exons of the androgen receptor gene of the two AIS girls and SSCP used to screen for mutations. DNA fragments showing abnormal SSCP pattern were subjected to nucleotide sequencing. PCR based diagnostic method was developed and used to detect the mutation causing AIS in the family. RESULTS AND CONCLUSIONS: Using SSCP and DNA sequencing a CGA to CAA missense mutation in exon 5 at codon 752 was identified. The mutation causes in an Arg to Gln amino acid substitution (R752Q mutation) in the ligand binding domain of the androgen receptor and a complete androgen insensitivity. Members of the family were genotyped using a PCR based method for identification of the mutant allele. The results strongly indicated a de novo mutation in a germ cell of the maternal grandmother, as the mutation was not found in her blood leucocytes. The diagnostic test provided a basis for genetic counselling for the family.

English Abstract↗
PubMed2000

[Puberty in Icelandic girls.].

In a crosssectional study, 2775 healthy Icelandic girls, aged 6-16 years, were examined for physical signs of puberty. The study was performed in 1983-1987 and was a part of a larger crosssectional study of growth and development of 5526 Icelandic children all of whom were examined by the authors. Breast development stage 2 according to Tanner (B 2) was considered the first sign of puberty in girls. The mean age of Icelandic girls reaching B 2 was 10.84 years (SD 1.43). The mean time interval between B 2 and menarche was 2.42 years. The first signs of pubic hair growth, Tanner stage 2 (PH 2) were found at 11.46 years (SD 1.25). The mean time interval between PH 2 and PH 5 was 3.40 years. Comparison with studies from other countries is difficult because of different methods and different study designs, but the timing and tempo of puberty in Icelandic girls seems to be similar to what has been reported from other Nordic countries and countries in Western-Europe.

English Abstract↗
PubMed2000

[Puberty in Icelandic boys.].

In a crosssectional study, 2751 healthy Icelandic boys aged 6-16 years, were examined for physical signs of puberty. The study was performed in 1983-1987 and was a part of a larger crosssectional growth study of 5526 Icelandic children all of whom were examined by the authors. Testicular volume of 4 ml (T 4) was considered the first sign of puberty in boys. The mean age of Icelandic boys reaching T 4 was 11.89 years (SD 1.08). The mean time interval between T 4 and T 12 was 2.21 years. The first signs of pubic hair growth, Tanner stage 2 (PH 2), were found at 12.74 years (SD 1.37). The mean time interval between PH 2 and PH 5 was 2.43 years. Even though comparison with studies from other countries is difficult because of different methods and different study design, we find that the timing and tempo of puberty in Icelandic boys is similar to what has been reported from other Nordic countries and countries in Western-Europe.

English Abstract↗
PubMedDate not supplied

[Height and weight of Icelandic children 6-20 years of age.].

INTRODUCTION: Monitoring growth rate in children reflects the state of health and nutrition of the individual as well as the state of health of a nation. Until now little information has been available about the growth pattern of Icelandic children. We report here the results of a nationwide cross-sectional study of growth in Icelandic children aged 6-20 years. MATERIAL AND METHODS: Height, standing and sitting and weight were measured in a total of 6500 schoolchildren, 3173 girls and 3327 boys. The measurements were performed 1983-1987. Children were randomly selected from The National Registry according to date of birth from both urban and rural areas of the whole country of Iceland. Stature was measured by a Harpenden stadiometer and the children were weighed in underwear only using a standardized scale. RESULTS: The mean values and standard deviations for height, standing and sitting and weight are presented in tables. Growth charts for height weigt and sitting height are presented. No difference in height and weight was found between children from rural and urban areas. The results show that the growth of Icelandic children is in all age groups almost identical to the growth of Norwegian children. Compaired to other Nordic and WHO growth standards, Icelandic children are tall, especially during early pubertal development. CONCLUSIONS: Icelandic children are tall and the growth of Icelandic and Norwegian children follows the same pattern wich supports the theory that the two nations are closely related.

English Abstract↗