Abstract
The last comprehensive epidemiological studies on familial sarcoidosis in the UK were more than twenty five years ago. One of these reported that in only 1.7% of index cases was another family member affected. In addition, a significant proportion of like-sex over unlike-sex pairs among both siblings and parent child associations was noted as well as an excess of mother-child over father-child associations. A peponderance of monozygous over dizygous twins was also recorded. This study aimed to identify the risk ratio (λR) for relatives of familial sarcoidosis in the UK and to determine if the previous epidemiological findings have remained persistent over time. Questionnaires were sent to 406 index patients. Two hundred and sixty eight replies (66%) were received. Twenty four of the original 406 index patients (5.91%) were found to have at least one other relative (first or second degree) with biopsy proven sarcoidosis. A λR value of 16 was calculated providing evidence for significant familial clustering of the disease. Ethnically the families comprised Caucasian (62.5%), Afrocaribbean (29.2%) and Asian (8.3%). Three sets of female twins (two monozygous and one dizygous) were included. Overall the mean age at diagnosis was 39.8 for females and 40.9 for males. The male to female ratio was 1:1.7. This differed only for the asian families of which all affected members were male. There was an equal distribution of like-sex and unlike-sex families as well as mother-child and father-child pairs. The like-sex families however were mainly female. Pulmonary involvement was predominant irrespective of ethnicity, as was the need for corticosteroid treatment. These results support the theory that a shared determinant (either genetic or environmental) is operating in familial sarcoidosis and suggest that this determinant is similar for all ethnic groups.
Original language | English |
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Pages (from-to) | A24 |
Journal | Thorax |
Volume | 54 |
Issue number | SUPPL. 3 |
Publication status | Published - Dec 1999 |
Externally published | Yes |