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Biomedical subjects

A Bygum

Publications and source records attributed to A Bygum.

13 recordsLinked to original sources
PubMed2006

A founder mutation for ichthyosis prematurity syndrome restricted to 76 kb by haplotype association.

Autosomal recessive congenital ichthyosis (ARCI) is a group of keratinisation disorders that includes the ichthyosis prematurity syndrome (IPS). IPS is rare and almost exclusively present in a restricted region in the middle of Norway and Sweden, which indicates a founder effect for the disorder. We recently reported linkage of IPS to chromosome 9q34, and we present here the subsequent fine-mapping of this region with known and novel microsatellite markers as well as single nucleotide polymorphisms (SNPs). Allelic association, evaluated with Fisher's exact test and P (excess), was used to refine the IPS haplotype to approximately 1.6 Mb. On the basis of the average length of the haplotype in IPS patients, we calculated the age of a founder mutation to approximately 1,900 years. The IPS haplotype contains a core region of 76 kb consisting of four marker alleles shared by 97.7% of the chromosomes associated with IPS. This region spans four known genes, all of which are expressed in mature epidermal cells. We present the results from the analysis of these four genes and their corresponding transcripts in normal and patient-derived samples.

Alleles↗
PubMed2000

A gene for hypotrichosis simplex of the scalp maps to chromosome 6p21.3.

Hypotrichosis simplex of the scalp (HSS) is an autosomal dominant form of isolated alopecia causing almost complete loss of scalp hair, with onset in childhood. After exclusion of candidate regions previously associated with hair-loss disorders, we performed a genomewide linkage analysis in two Danish families and localized the gene to chromosome 6p21.3. This was confirmed in a Spanish family, with a total LOD score of 11.97 for marker D6S1701 in all families. The combined haplotype data identify a critical interval of 14.9 cM between markers D6S276 and D6S1607. Localization of the locus for HSS to 6p21.3 is a first step toward identification of the gene. The gene will give important insights into the molecular and cellular basis of hair growth on the scalp.

Adolescent↗
PubMed2000

[Giant cell arteritis and scalp necrosis].

We present a case of a 75-year old woman, who developed scalp necrosis as a result of giant cell arteritis in the temporal arteries. This is a very rare, but serious complication of temporal arteritis, which implies an increased risk of visual loss and other catastrophic sequelae. Healing of the ulceration was achieved after cortico-steroid therapy supplemented with split skin transplantation.

Aged↗
PubMed2000

[Porphyria cutanea tarda].

Porphyria cutanea tarda (PCT), the most common porphyria disease, is characterized by blistering and skin fragility of sun-exposed skin. The symptoms are caused by lowered activity of uroporphyrinogen decarboxylase (URO-D) resulting in accumulation of water-soluble porphyrins in the skin. Most PCT cases are sporadic but can be familiar due to mutations in the URO-D gene located on chromosome number 1. The disease may be exacerbated by environmental factors. Iron accumulation is a characteristic finding and there is an association to hereditary haemochromatosis. Therapeutic venesection reduces the iron load and the uroporphyrins are mobilized by treatment with hydroxychloroquine. An increased risk of liver cirrhosis and hepatocellular carcinoma may presumably be reduced by early diagnosis and treatment.

Humans↗
PubMed2000

[Asymmetric periflexural exanthema of childhood].

Asymmetric peri-flexural exanthem of childhood is a "new" disease, which has never been reported by Danish authors. It is characterized by an asymmetric maculopapular exanthem in early childhood. The exanthem is initially unilateral and localised close to the axilla, but it spreads centrifugally during the first week, becomes more widespread and resolves spontaneously within four to six weeks. We describe two cases of this entity.

Axilla↗
PubMed2000

Association between CYP1A2 polymorphism and susceptibility to porphyria cutanea tarda.

Individuals with the most common form of the porphyrias, porphyria cutanea tarda (PCT), are believed to be genetically predisposed to development of clinically overt disease through mutations and polymorphisms in genes associated with known precipitating factors. In this study, we have examined a group of Danish patients with PCT for the presence of the C/A polymorphism in intron 1 of CYP1A2. The results demonstrate that the frequency of the highly inducible A/A genotype is increased in both familial and sporadic PCT. This suggests that inheritance of this genotype is a susceptibility factor in development of PCT.

Cytochrome P-450 CYP1A2↗
PubMed2000

Uroporphyrinogen decarboxylase gene mutations in Danish patients with porphyria cutanea tarda.

Decreased uroporphyrinogen decarboxylase (UROD) activity is a characteristic feature of the most common of the porphyrias, porphyria cutanea tarda (PCT). A subgroup of the clinically overt PCT cases is associated with mutations in the gene encoding UROD and inherited as an autosomal-dominant trait. In this study, DNAs from 53 Danish PCT patients were subjected to genetic analysis for UROD mutations using denaturing gradient gel electrophoresis. Eleven genetic variations, seven of which are possible disease causing, were identified. All but one of these mutations were previously unknown, lending further support to the assumption that PCT is a heteroallelic disease. Only 11% of the examined patients were previously recognized as familial PCT cases. However, possible disease-related UROD mutations were identified in 24% of the examined patients, indicating that genetic analysis of PCT patients may improve differentiation between familial and sporadic PCT cases.

Base Sequence↗
PubMed1998

[Granuloma annulare after herpes zoster: isotopic response].

A 33 year-old woman was seen with a localized zosteriform papular eruption in a Th7 dermatomal distribution. The patient experienced neuralgic pain. A skin biopsy demonstrated palisading granulomatous dermatitis and a diagnosis of granuloma annulare after a subclinical herpes zoster infection was made. "Isotopic response" describes the occurrence of a new disorder at the site of another, unrelated, and already healed skin disease.

Adult↗
PubMed1997

[Mealworm allergy].

A 24 year-old female employed in a pet shop developed occupationally related asthma, rhinoconjunctivitis and contact urticaria caused by exposure to the yellow mealworm (Tenebrio molitor Linnaeus) sold as food for birds and reptiles. A wholebody extract of the mealworm showed positive prick test and histamine release.

Adult↗