To the Editor.
—Dr. Scheinberg's provocative article titled "The Genetics of Hemochromatosis" in the Archives (132:126, 1973) and Dr. Crosby's reply (133:1072, 1974) warrant further comment in the light of recent new data on the subject.Dr. Scheinberg postulates that hemochromatosis results from inheritance of a recessive trait, a pair of abnormal alleles (homozygotes) leading to the classical "end-stage" disease in nonalcoholic subjects, whereas a single abnormal allele (heterozygote) may also be associated with phenotypic effects if environmental factors, notably alcoholism, accelerate the iron excess. He designates the first situation as "primary hemochromatosis" and the disease in heterozygotes as "secondary hemochromatosis." Dr. Crosby, on the other hand, suggests that hereditary hemochromatosis represents a group of diseases and that "it is most unlikely that one pattern of inheritance will be found to fit them all." Dr. Crosby cites our family study (Lancet 2:555, 1964) as evidence of dominant inheritance; Dr. Scheinberg