Spondylometaphyseal dysplasia: further heterogeneity.

The spondylometaphyseal dysplasias are a very heterogeneous group of disorders. Only one has been clearly defined, namely, the spondylometaphyseal dysplasia--Kozlowski type, known also as the "common type." This disorder is inherited as an autosomal dominant trait. In this report we describe an Arabic-Moslem kindred with spondylometaphyseal dysplasia, not of the common type, with an autosomal dominant mode of inheritance, indicating further heterogeneity.

Chediak-Higashi syndrome. Expression of the cytoplasmic defect by in vitro cultures of bone marrow progenitors.

Studies on proliferation and differentiation of granulocyte-monocyte progenitor cells in Chediak-Higashi syndrome (CHS) were done on a 1-month-old patient, using the soft-agar bone marrow culture technique. The number of granulocyte-macrophage colony-forming cells (GM-CFC) was markedly increased, but with a normal distribution into granulocyte, macrophage, or mixed colonies. Morphologic, cytochemical, and ultrastructural studies showed that 70% of the colonies consisted of cells with giant lysosomes typical of CHS, and in the remaining 30% abnormal cells were not detected. The supply of granulocyte-macrophage colony-stimulating factor (GM-CSF) by the patient's peripheral blood leukocytes was markedly decreased. Inhibition of normal in vitro granulopoiesis by the patient's lymphocytes or serum was not demonstrated. It appears that granulocyte progenitors in CHS proliferate normally, or even in excess, probably in response to intramedullary destruction of granulocytes. The majority of the progenitors are intrinsically defective and give rise to colonies that contain the abnormality. In others the defects are unidentifiable, probably due to the immaturity of the specific fusion process of the cytoplasmic granules. The abnormal leukocytes in CHS are also defective in their capacity to provide GM-CSF, and this may account in part to the overt neutropenia. These studies demonstrate that the basic cytoplasmic abnormalities of the granulocytes and monocytes in CHS are embedded in the granulocytic-monocytic committed stem cell.

Infantile nephrotic syndrome. Clinicopathological study of 11 cases.

The clinical picture and histopathological findings in 11 infants with infantile nephrotic syndrome are presented. Three infants, who presented in the perinatal period, had congenital nephrotic syndrome (Finnish type); six of eight infants who presented in the 1st yr of life had mesangial sclerosis nephrotic syndrome, while the remaining two had minimal change nephrotic syndrome. Four of the six infants with mesangial sclerosis nephrotic syndrome were from one family. All patients died within 2 mo to 2 yr after presentation.