PubMed Health⌕ Search

Biomedical subjects

T Rosenberg

Publications and source records attributed to T Rosenberg.

At least 19 recordsLinked to original sources
PubMed1995

[Molecular genetics of red-green color blindness].

Normal colour vision is trichromatic and is mediated by the blue, green and red visual pigments present in the corresponding blue, green, and red cone cells of the retina. The red and green pigment genes have evolved from an ancestral pigment gene and reside in a head-to-tail tandem array on the long arm of the X chromosome. This arrangement and a high degree of homology predispose to illegitimate recombination between the red and green pigment genes explaining the various forms and the high frequency of red-green colour vision defects.

Color Vision Defects↗
PubMed1995

[Molecular genetic examination in sex-linked color blindness].

The molecular structure of the X-linked colour-vision locus was studied in a family where mild red-green colour-vision deficiency (deuteranomaly) segregated, and in a male with complete absence of red and green colour-vision (blue cone monochromasy). In individuals with normal colour-vision the red and green pigment genes had normal molecular structure whereas individuals with deuteranomaly, in addition to normal red and green genes, also had an abnormal hybrid gene consisting of parts of the green and red pigment genes. The individual with blue cone monocromasy had only a red-green hybrid gene inactivated by a critical mutation in codon 203. Thus, the phenotypes predicted from the individual genotypes were in complete accord with the observed phenotypes.

Adult↗
PubMed1995

[Hereditary optic nerve atrophy. A clinical-genealogical status over Danish families with Leber disease].

An update on Leber's hereditary optic neuropathy (LHON) in Denmark disclosed 32 families with at least one live affected member, or recent disease onset (Table 1). Mitochondrial DNA analysis in the 30 families available for blood sampling identified the pathogenic mutation in all of them: ND4/11778 (26 families), ND1/3460 (three families), and ND6/14484 (one family). A previous distinct male dominance (sex ratio 4.6:1 in 157 ND4-patients with onset before 1968) seems to level (sex ratio 2.6:1 in 69 ND4-patients with onset in 1968 or later). Among possible explanations, we discuss improved diagnostic abilities and possible changes in women's alcohol consumption and smoking habits.

Adolescent↗
PubMed1995

Assignment of congenital cataract Volkmann type (CCV) to chromosome 1p36.

Congenital cataract, type Volkmann (McKusick no 115665, gene symbol CCV) is an autosomal dominant eye disease. The disease is characterized by a progressive, central and zonular cataract, with opacities both in the embryonic, fetal and juvenile nucleus and around the anterior and posterior Y-suture. We examined blood samples from 91 members of a Danish pedigree comprising 426 members, by using highly informative short tandem repeat polymorphisms and found the closest linkage of the disease gene (CCV) to a (CA)n dinucleotide repeat polymorphism at locus D1S243 (Zmax = 14.04 at theta M = 0.025 theta F = 0.000), at a penetrance of 0.90. Using two additional chromosome 1 markers, we were able to map the CCV gene in the sequence 1pter-(CCV, D1S243)-D1S468-D1S214. The (enolase 1) gene has been mapped to this area; however, a mutation described in this gene did not give eye disease.

Cataract↗
PubMed1995

Leber's hereditary optic neuropathy: implications of the sex ratio for linkage studies in families with the 3460 ND1 mutation.

Leber's hereditary optic neuropathy (LHON), which is associated with mutations in mitochondrial DNA (mtDNA), is commoner in males than females. A study of over 30 LHON families with a mutation at position 3460 of mtDNA demonstrates a significantly decreased male excess from that generally quoted, with evidence for a marked bias in the ascertainment of males over females. This has implications for the analysis of those factors which give rise to the male bias.

Adult↗
PubMed1995

Laboratory measurements of the transport of radon gas through concrete samples.

Experiments were conducted to measure the transportability of radon gas through common concrete samples which were characterized by their mix proportions, dimensions, porosity, air permeability, and radon gas diffusion coefficient. Several innovative test systems and methods were designed, fabricated, and calibrated to accurately measure these radon gas transport characteristics for concrete and to overcome many of the shortcomings of previously published experimental works. From the experimental results, it was found that diffusion is the dominant transport mechanism by which radon gas moves through an intact concrete slab. It was also shown that indoor radon entry rates can be greatly affected by the type of concrete mix employed. The results of this study can be utilized to improve the present technology of radon-resistant construction techniques for new residential construction.

Air Pollution, Indoor↗
PubMed1995

Leber's hereditary optic neuropathy associated with a disorder indistinguishable from multiple sclerosis in a male harbouring the mitochondrial DNA 11778 mutation.

This report describes a multiple sclerosis (MS)-like disorder in a male patient with Leber's hereditary optic neuropathy (LHON) harbouring the mitochondrial DNA 11778 base pair mutation. Given the population frequencies of MS and LHON, coincidental occurrence is unlikely. Hypothetically the mitochondrial mutation underlying LHON may contribute to presumably immunologically mediated involvement of other myelinated axons in the central nervous system in susceptible individuals, producing a disorder indistinguishable from MS. We recommend that investigation for oligoclonal bands in CSF, evoked potentials and MR brain scan in these patients be supplemented with mitochondrial DNA analysis.

Adult↗
PubMed1995

Clinical pathology and retinal vascular structure in the Bardet-Biedl syndrome.

A comparative study of clinical pathology and retinal vascular structure is described as studied by vascular casting in an eye of a patient with the Bardet-Biedl syndrome. At the time of examination the eye had been almost blind for at least 4 years. The histopathological examination showed a largely uniform loss of the outer retinal layers. The gross pathological examination of the cast ocular fundus showed three distinct zones, an inner zone inside the temporal vascular arcades where retinal vessels had been cast, a mid peripheral zone with bone spicules, and a peripheral zone with neither cast vessels nor bone spicules. The findings are discussed in relation to possible pathophysiological mechanisms involved in the development of retinal dystrophy in the Bardet-Biedl syndrome.

Female↗
PubMed1994

Gene for autosomal dominant congenital stationary night blindness maps to the same region as the gene for the beta-subunit of the rod photoreceptor cGMP phosphodiesterase (PDEB) in chromosome 4p16.3.

We studied a large multigeneration Danish family with autosomal dominant congenital stationary night blindness. Both electrophysiological and psychophysical findings in affected family members were identical to those reported in patients from the 'Nougaret family'. The disease locus in the Danish family has now been mapped by demonstrating close linkage without recombination (Q = 0.00 at Zmax = 14.4) to the locus for alpha-L-iduronidase assigned to chromosome 4p16.3. Interestingly the gene for the beta-subunit of the rod photoreceptor cGMP-specific phosphodiesterase maps to the very same chromosomal region.

Chromosome Mapping↗
PubMed1994

Dominant optic atrophy (OPA1) mapped to chromosome 3q region. I. Linkage analysis.

Dominant optic atrophy, type Kjer (McKusick no. 165500) is an autosomal dominant eye disease. The disease is characterized by moderate to severe visual impairment with an insidious onset during the first decade of life, blue-yellow dyschromatopsia and centrocecal scotoma of varying density. We examined three extended Danish pedigrees using highly informative short tandem repeat polymorphisms and found linkage of the disease gene (OPA1) to a (CA)n dinucleotide repeat polymorphism at locus D3S1314 (Zmax = 10.34 at theta M = F = 0.075). Using two additional chromosome 3 markers we were able to map the OPA1 gene in the region between D3S1314 and D3S1265 (3q28-qter).

Chromosome Mapping↗
PubMed1994

Age differences of visual field impairment and mutation spectrum in Danish choroideremia patients.

Visual prognosis is a crucial theme in the counselling of individuals affected by a progressive retinal dystrophy. Unfortunately prognostic predictions are hampered by large interindividual differences in disease courses even within well defined nosological entities. Ten patients from 8 families affected by choroideremia were studied. The clinical signs in our patients were rather uniform. Deterioration of the peripheral visual fields typically began in the second decade of life, and progressed during the following one or two decades. Esterman transformation of peripheral visual field measurements was chosen as the best single indicator of visual impairment. Noticeable age differences in residual visual fields among patients were demonstrated. The age difference between the mildest and the severest cases amounted to 25 years. One of the expectations of the exploration of disease genes, is the potential predictive value of mutation identification with regard to phenotypic variability. Different presumed causative mutations were identified. Nevertheless, all the mutations are predicted to cause premature stops during translation, resulting in a non-functional or missing protein. Consequently, the observed age variation in the photopic visual field degradation must be due to still unrecognized factors, either constitutional and/or environmental.

Adolescent↗
PubMed1992

Autosomal dominant congenital cataract; linkage relations; clinical and genetic heterogeneity.

Congenital cataract is a heterogeneous disorder. Approximately one third of the cases are hereditary. A large family with autosomal dominant congenital cataract is described here. Clinical examinations showed variable expressivity, but all affected persons were eventually operated, most of them in the first or second decade of life. Linkage relations with a number of polymorphic marker systems were studied, all of them being negative. Among the 21 systems studied were Fy, HP, D16S4 and CRYG. The present autosomal dominant congenital cataract is termed the Volkman cataract, after the ancestor in the pedigree, and is genotypically different from the Marner cataract found in another large Danish pedigree.

Cataract↗
PubMed1992

Visual impairment in Nordic children. III. Diagnoses.

The diagnoses, according to type and site and the degree of visual impairment, responsible for severe visual impairment in children below the age of 18, were analyzed in a material compiled from the national registers of visually impaired in Denmark, Finland, Iceland and Norway. Among 2527 children the predominant causes of visual impairment are ascribed to congenital malformations, neuro-ophthalmological diseases and retinal diseases. Optic atrophy is the leading single cause of severe visual impairment when all diagnoses are compared, and this also applies when all categories of visual impairment are included. Retinopathy of prematurity is the second principal cause of severe visual impairment, while cerebral amblyopia rates as the third most significant cause. Congenital cataract is also of considerable importance when all categories of visual impairment are compared. The differences registered between the Nordic countries were found to be within reasonable limits, except for a preponderance of neuro-ophthalmological diseases in the Danish material. This could be explained by a better medical supervision of mentally retarded patients in Denmark. Additional impairments occur in a large percentage of patients, but are unevenly distributed in the disease groups. A high frequency of additional impairments are found in the neuro-ophthalmological group and in the groups with congenital malformations, emphasizing the importance of a multidisciplinary evaluation when dealing with the visually impaired child.

Adolescent↗
PubMed1992

Visual impairment in Nordic children. IV. Sex distribution.

A Nordic study group of ophthalmologists, NORDSYN, has compiled registers in Denmark, Finland, Iceland and Norway of 2527 visually impaired children aged 0-17 years. This paper is concerned with the sex-distribution in the registers and has documented a statistically significant excess of males in two of the registers (Denmark and Finland). The dominance of males seems to be related to two main conditions: 1. Genetic factors. 2. Perinatal factors. The genetic factors are mainly concerned with X-linked inheritance. The fact that perinatal influences involve visual impairment in males more than in females is difficult to account for. It may be conjectured, that the basis for perinatal visual damage is determined by unknown prenatal, possibly genetic, factors.

Adolescent↗
PubMed1992

Birdshot retinochoroidopathy in monozygotic twins.

Birdshot retinochoroidopathy is a rare ocular disorder which was named and delineated as a separate clinical entity by Ryan & Maumenee in 1980. We diagnosed birdshot retinochoroidopathy in a monozygotic pair of twins, who were affected with a time interval of 12 years, respectively. These are the first with birdshot retinochoroidopathy to be reported from the Nordic countries and the first report on this disorder in monozygotic twins. Due to night-blindness, visual field defects and a severely affected electroretinogram one of our cases initially was diagnosed as a choroidoretinal dystrophy. Birdshot retinochoroidopathy should be kept in mind as a differential diagnosis in retinitis pigmentosa-like disorders with widespread choroidal involvement. Our cases substantiated the evidence of a strong correlation with the presence of HLA-A29 antigen.

Chorioretinitis↗
PubMed1992

Visual impairment in Nordic children. I. Nordic registers and prevalence data.

A Nordic study group of ophthalmologists, NORDSYN, has compiled data from registers in Denmark, Finland, Iceland and Norway of 2527 visually impaired children. Each record contains the following information: sex, year of birth, year of registration, classification of visual impairment, ocular diagnosis, systemic diagnosis, aetiology and evt. additional impairments. The ocular diagnoses were compiled into groups, and coding systems for aetiology and additional impairment were developed. The sex distribution revealed a dominance of males compared to the general population at the same age. Cases with non-genetic aetiology showed--through to a lesser extent--the same relative preponderance of males. The diseases in males caused by x-linked genetic factors do, therefore, not fully explain the sex distribution observed in the study. The national prevalences for registration of childhood blindness (WHO-definition: best corrected visual acuity in the best eye less than 3/60 or visual field less than 10 degrees around fixation for the ages 0-15 years) are per 100,000 child-population aged 0-15 years: Denmark 41, Finland 15, Iceland 19 and Norway 15. The differences are primarily presumed to be due to varying efficiency in registration. The proportion of visually impaired children with an additional mobility, hearing or mental impairment is between one-third and one-half of the national materials, thus indicating the need for interdisciplinary tracing of and care for the visually impaired child. This study documents the need of uniform routines for data classification of visually impaired children. The quality of the data in the present study calls for caution in the interpretation of the prevalence estimates. Incidence studies are being prepared to obtain information on whether the amount and causes of visual impairment in children with or without multiple impairments are changing.

Adolescent↗