Age-related macular degeneration (AMD) is a heterogeneous group of disorders and is the leading cause of blindness in the elderly. While degeneration changes in the macula can occur at any time in life, it is the most common cause of severe visual impairment with advancing age. The disease affects approximately 11 million Americans and causes loss of central vision, impairing activities such as reading. The exact cause of the disorder is not known. In this report, we studied two unrelated families having familial-type AMD, with the assumption that mutations in the peripherin/retinal degeneration slow (RDS) gene could contribute to the disease phenotype. Our extensive analyses have identified two silent mutations (84D and 106V) in one family in the same allele of exon 1 which segregated in 3 patients with AMD. However, the fourth affected individual in the same family, as well as 40 normal controls, did not contain this mutation. Further analysis of exon 2 and exon 3 in both families did not show any other sequence alterations. Since one of these silent mutations (106V) has been reported to exist in certain general populations and the other mutation (84D) failed to segregate completely in the family, it is unlikely that these mutations are pathogenic. The results of the study suggest that the peripherin/RDS gene is not a major factor responsible for AMD in the families analyzed.