Linkage Study of Long QT Syndrome In An Amish Kindred

BACKGROUND: LQTS is a severe heart disorder leading to sudden death due to ventricular tachycardia or ventricular fibrillation. The syndrome segregated as a Mendelian recessive in the highly inbred population under study and resulted in the sudden death of several members of the population. DESIGN NARRATIVE: The entire population was screened to identify cases of LQTS. In addition, 29 obligate heterozygotes were studied by 24-hour Holter monitoring to determine whether these gene carriers had any subtle phenotypes. The data were subjected to complex segregation and linkage analysis to establish the mode of inheritance and penetrance of LQTS. The study completion date listed in this record was obtained from the "End Date" entered in the Protocol Registration and Results System (PRS) record.