RESUMO
BACKGROUND:- Human T-cell lymphotropic virus type I (HTLV-I) infection is endemic in Jamaica, with an estimated crude seroprevalence of 5percent. Adult T-cell lymphoma/Leukemia (ATL), a disease caused by HTLV-I, has an incidence of 1-2/100,000 in the Jamiacan population. Familial ATL has not previously been reported from Jamaica. METHODS:- Hospital records and histologic specimens of the two cases were reviewed. HTLV-I infection was confirmed by antibody testing and by polymerase chain reaction on paraffin-embedded tissue,where serum was unavailable. Family members identified by the patient's parents. After giving informed consent, family members were asked to complete an interviewer-administered questionnaire and to agree to phlebotomy. RESULTS:- ATL developed 10 years apart in two siblings from a Jamaican family at age 16 and 24 years. A study of 19 members of their extended family, including both parents, 2 grandparents, and 3 siblings, revealed an overall HTLV-I seroprevalence of 17 percent. This compared with 75 percent among parents and sibling living in the same household as the patients (AU)