A family study on primary blepharospasm

Abstract

Background: Previous family studies provided evidence that blepharospasm (BSP) can aggregate in families but did not give accurate and reliable information on the characteristics and degree of familial clustering. Aim: To evaluate the proportion of familial and non-familial BSP cases, the clinical expression of dystonia within families, the inheritance pattern, and the extent of penetrance. Methods: The study was based on the examination of the first degree relatives of 56 probands with primary BSP. Results: The 56 families produced a potential population of 436 first degree relatives of whom 296 were alive and 233 were examined. The proportion of index patients with at least one first degree relative affected by BSP, or adult onset dystonia other than BSP, was 27%. There was a remarkable degree of phenotypic variability of dystonia within families. Similar segregation ratios were calculated for probands' siblings and children. Under the assumption of autosomal dominant transmission of adult onset dystonia, penetrance was about 20%. Conclusions: The findings of this family study are relevant for accurately counselling the families of patients with BSP and may help identify the most appropriate study design to explore genetic susceptibility in BSP.

Traditional eye medication and pterygium occurrence in Limpopo Province

“…Diagnosed pterygiumaffected key relatives were associated with pterygium occurrence, so confirming familial occurrence, which is a similar finding to that in a report on primary blepharospasm. 15 The association of diagnosed pterygium-affected relatives with pterygium cases has not been reported before. Since alleles may or may not be transmitted, this explains why some families had 1 or 2 affected individuals.…”

“…19 Moreover, heredity explains the tendency of larger families to have more affected members. 15,20 Because some patients were exposed for short durations, sunlight despite low exposure may be only a trigger for pterygium to occur in predisposed individuals. As the level of education was equally low among patients and controls, and the available employment was mainly on farms (as reported before 21 ), these may be reasons why controls were as excessively exposed to sunlight and dust as the cases.…”

“…15 The difference in proportion of pterygium-affected individuals between the combined families of the cases and those of the controls was compared. The proportion of pedigrees having a group of pterygium-affected individuals was compared between cases and controls.…”

Clinical features and treatment with botulinum toxin in blepharospasm: a 17-year experience

“…We have to highlight that this data was acquired through patient report and that their family members were not examined in our center. Positive family history in previously published articles ranged from 7 to 32%, according to distinct methodology and population studied 8,12,13,15 .…”

“…Complaints of dry eye and photophobia are usually reported, but the exact nature of this association remains unestablished 5 . Finally, concerning the genetic pattern and inheritance of BPS, it seems that there is a higher frequency of focal dystonia in relatives, however with a considerable phenotypic variability 8 . The purpose of this study was to evaluate the demographic and clinical features, including outcomes of botulinum toxin treatment in patients with BPS referred to a Brazilian tertiary care center.…”