Biomedical subjects
Publications and source records attributed to A Bygum.
Explore the source record for details and available documents.
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.
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.
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.
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.
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.
Explore the source record for details and available documents.
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.
Explore the source record for details and available documents.
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.
Explore the source record for details and available documents.
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.