Familial clustering of presumptive sudden unexplained death syndrome (PSUDS).

Regarding the suggestion that presumptive sudden unexplained death syndrome (PSUDS) may be genetically associated, we recently conducted a study to reveal the clustering of the PSUDS in extended families. The data collection was done through case searching, interviewing using structured questionnaires and cross-referencing among informants. The precise criteria were used to identify the SUNDS cases. The collected data were age, sex, time and place of death, details of events at death, and vital statistics of relatives. There were forty-nine families with 418 family members included in the study. Twenty-five cases of PSUDS were reported from 14 families. All were men, with the mean age (+/- SD) 31.26 (+/- 7.01) years and the age range was 25-50. There were 6 clusters of SUNDS in sibling groups. Three of the clusters consisted of three siblings each and the other three clusters consisted of two siblings each. Most of the individuals in the siblings clusters had different occupations and died in different places and in different years. The aggregation of PSUDS in families is demonstrated. However, whether it is genetically related needs further study.