A new restless legs syndrome locus on chromosome 14 recently has been reported in one family of Italian origin. Our study aimed to replicate this finding and determine the importance of this locus in the French Canadian population. Markers spanning the region were genotyped in 14 large families and linkage assessed using two-point and multipoint logarithm of odds scores. Possible linkage to this locus was found in one of our kindreds providing support for the existence of this locus and indicating that this locus may be responsible for a small fraction of French Canadian restless legs syndrome.
The first Danish case of Aarskog syndrome is reported. The child had attended several specialized out-patient clinics before the diagnosis was suggested. This underlines the need for dysmorphology in paediatrics.
In the northernmost county of Sweden (Norrbotten) two different clinical and genetic types of hereditary palmoplantar keratoderma have been reported: a common autosomal dominant form, corresponding to the descriptions performed by Unna and Thost, and an obviously autosomal recessive form, which clinically differed from other diffuse palmoplantar keratodermas, named the Gamborg Nielsen type. For further family studies and to support its probably recessive inheritance a demographic mapping of four families with this rare keratinization disorder was performed. It could be shown that these families belonged to the same family at different levels of generations; however, a common ancestor, who connected these families was not found. Marital distance of heterozygotes and birth places of probands were limited to an area, which is generally known to harbour different inherited disorders. According to a map of the origin of family members, it was shown that the major part originated from the same area and that the integration of family members had occurred in the same places. It was concluded that adoption of a demographic database for family studies in genetic research may contribute valuable information about family relations.
To describe an unusual kindred with adult-onset ataxia and thalamic lesions detected by brain MRI.
The authors characterized clinical, laboratory, and pathologic features of the disease and sought linkage to previously recognized ataxia loci.
Two sisters and a brother developed progressive ataxia, dysarthria, mild cognitive impairment, and sensorimotor neuropathy at age 30, combined with epilepsy in one sibling. MRI showed symmetric thalamic lesions, changes in brainstem gray matter, and white matter changes in the cerebellum. Autopsy in one of the patients revealed neuronal degeneration with a peculiar vacuolar change in thalamus, probably representing transsynaptic degeneration in response to deafferentation. Neuronal and secondary tract degeneration was observed in the spinal cord, cerebellum, and brainstem suggesting a spinocerebellar degeneration. The disorder appears to be transmitted as an autosomal recessive trait. Genetic and sequence analysis of the FRDA gene and comprehensive laboratory examinations excluded Friedreich's ataxia and other similar recessive diseases.
Adult-onset recessive ataxia with bilateral thalamic lesions in this family may represent a distinct hereditary spinocerebellar ataxia.
The spinocerebellar ataxias (SCAs) are a genetically and clinically heterogeneous group of neurodegenerative disorders. Relative frequencies vary within different ethnic groups and geographical locations.
1) To determine the frequencies of hereditary and sporadic adult onset SCAs in the Movement Disorders population; 2) to assess if the fragile X mental retardation gene 1 (FMR1) premutation is found in this population.
A retrospective chart review of individuals with a diagnosis of adult onset SCA was carried out. Testing for SCA types 1, 2, 3, 6, 7, and 8, Dentatorubral-pallidoluysian atrophy (DRPLA), Friedreich ataxia and the FMR1 expansion was performed.
A total of 69 patients in 60 families were identified. Twenty-one (35%) of the families displayed autosomal dominant and two (3.3%) showed autosomal recessive (AR) pattern of inheritance. A positive but undefined family history was noted in nine (15%). The disorder appeared sporadic in 26 patients (43.3%). In the AD families, the most common mutation was SCA3 (23.8%) followed by SCA2 (14.3%) and SCA6 (14.3%). The SCA1 and SCA8 were each identified in 4.8%. FA was found in a pseudodominant pedigree, and one autosomal recessive pedigree. One sporadic patient had a positive test (SCA3).Dentatorubral-pallidoluysian atrophy and FMR1 testing was negative.
A positive family history was present in 53.3% of our adult onset SCA patients. A specific genetic diagnosis could be given in 61.9% of dominant pedigrees with SCA3 being the most common mutation, followed by SCA2 and SCA6. The yield in sporadic cases was low. The fragile X premutation was not found to be responsible for SCA.
A genetic and epidemiological sample of 20-59-year-old males, Moscow residents (n = 3141), was surveyed. The authors obtained data on the prevalence of coronary heart disease from epidemiological criteria and genealogical data on cardiovascular diseases by the "Familial History" questionnaire in the first-degree relatives who were interviewed by using a genetic and mathematical monolocus diallelic model. It was found that out of the 10 possible variants under study a genetic and environmental variant with independent penetrance of 3 genotypes adequately describes the prevalence of coronary heart disease in the families and in the population. This suggest that both genetic and environmental factors have an influence on the prevalence of coronary heart disease and that there is a possible genetic polymorphism of the disease.
BACKGROUND: Systematic comparisons of mode of inheritance for renal cell carcinoma (RCC) have not been carried out. The occurrence of cancer in parents and offspring may be due to dominant causes, whereas cancer affecting only siblings may indicate a recessive causation. Environmental effects need to be excluded. METHODS: The Swedish Family-Cancer Database includes all Swedes born after 1931 with their biologic parents, totaling 10.2 million persons. Cancer data were retrieved from the Swedish Cancer Registry from years 1961 to 2000, included 2415 cases of RCC in offspring and 18531 in parents. Standardized incidence ratios (SIRs) and 95% CI limits were calculated for offspring whose parents or sibling were diagnosed with RCC. RESULTS: The SIRs for siblings for RCC depended on their age difference. SIR was 7.63 (95% CI 3.63-14.08) when the age difference was less than 3 years and compared to 3.43 (95% CI 1.77-6.02) for large age difference. SIRs for familial risk of RCC were 1.73 (95% CI 1.31-2.26) when a parent and 4.58 (95% CI 2.87-6.94) when a sibling had RCC. Age-specific analysis of familial RCC among siblings revealed maxima at ages 40 to 49 and 60 to 68 years. CONCLUSION: The findings in the present study offer evidence on recessive effects in early onset RCC.
Allgrove syndrome (isolated glucocorticoid deficiency, achalasia and alacrima) was found in eight members of an inbred French Canadian/North American Indian pedigree. The high degree of consanguinity supports an autosomal recessive mode of inheritance for this disorder. Six patients presented with hypoglycaemia and other evidence of cortisol deficiency between 2.5 and 8 years of age; however, two others became cortisol deficient after initial testing showed normal cortisol responses to ACTH, evidence that the glucocorticoid insufficiency of this syndrome may not be congenital, but may develop as late as the third decade. No evidence of mineralocorticoid deficiency has been found during 65 patient-years of follow-up. Alacrima was the earliest and most consistent clinical sign of Allgrove syndrome. Other manifestations of peripheral or autonomic neuropathy were found in four patients. The patients showed similar facial features, and three had significant velo-pharyngeal incompetence. All showed oesophageal dysmotility even in the absence of symptomatic dysphagia. In-vitro studies of lymphocyte ACTH binding showed no differences from normal controls. If such lymphocyte binding, as has been suggested, reflects adrenal ACTH receptor activity, these data would suggest that the glucocorticoid deficiency of Allgrove syndrome is not the result of a defect in that receptor. However, the observation that ACTH does not elicit increased adenylate cyclase activity even in normal lymphocytes casts considerable doubt on the physiological significance of ACTH binding to lymphocytes. It seems likely, therefore, that true ACTH receptors are not expressed on peripheral lymphocytes, and any conclusions regarding a possible receptor defect in Allgrove syndrome must await studies of receptor expression on adrenal cell membranes.