Autosomal dominant polycystic kidney disease (ADPKD) is caused by at least two different genes. The ADPKD 1 gene is located on chromosome 16p and a second locus is at 4q. Although the ADPKD 1 gene is responsible for the majority of the disease in whites, there was no information regarding the gene type in blacks. We studied a black family which presented with both ADPKD and sickle-cell trait (SA) to determine which ADPKD gene was present in this family, and to examine linkage between the ADPKD in this family and markers for the β-hemoglobin gene on chromosome 11. The ADPKD in this family was linked to markers on chromosome 16, and no linkage was found with the β-hemoglobin gene. Family members with SA and ADPKD had an early onset of end-stage renal disease. The hemoglobin haplotype was identified as the Central African Republic-type, which has been reported to be associated with a higher incidence of renal failure in sickle-cell anemia.