Familial occurrence of histiocytosis.

The clinical and histological findings of four children with lethal histiocytosis are reported. The children belonged to two sibships and originated from a Swedish geographical isolate. Consanguinity between the parents was established for one of the sibships, belonging to a pedigree in which malignant disease occurred in two generations. The observations indicate that the type of histiocytosis investigated is caused by homozygosity for a single recessive gene. The association between histiocytosis and malignancy is discussed.