Data were analyzed from 419 Fanconi anemia (FA) patients enrolled in the American Registry of the International Fanconi Anemia Registry (IFAR) to determine whether Fanconi anemia (FA) patients without major congenital malformations (CM) have distinguishing characteristics that can lead to an earlier diagnosis. These included 377 patients reported by physicians to the IFAR and 42 patients examined by us. The number of FA patients in each group without CM was 128 and 16, respectively; one third of all patients lacked CM. We found that height, weight, and head circumference were < or = 5th centile in 26.6%, 18.0%, and 8.6% of FA patients without CM referred to the IFAR, and in 43.8%, 25.0%, and 43.8% of FA patients without CM examined by us. Minor anomalies were reported in 9.4% of FA patients without CM referred to the IFAR and 100% of FA patients without CM examined by us. Most FA patients without CM have alterations in growth parameters, skin pigmentation abnormalities, or microphthalmia. Increased awareness of the complete spectrum of FA by clinicians will enable an earlier diagnosis to be made.