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A group of fetuses with a perinatally lethal variety of osteogenesis imperfecta (O.I. type II) is characterized by short limbs, and clinical and roentgenological evidence of severe osseous fragility and defective ossification. Forty-eight cases were reviewed and can be subdivided into 3 groups on the basis of small but probably significant differences in clinical and radiographic findings. Group A (38 cases): short, broad, "crumpled" long bones, angulation of tibiae and continuously beaded ribs. Group B (6 cases): short, broad, crumpled femora, angulation of tibiae but normal ribs or ribs with incomplete beading. Group C (4 cases): long, thin, inadequately modelled, rectangular long bones with multiple fractures and thin beaded ribs. Consistency of findings within sibships suggests the groups reflect genetic heterogeneity. An increased frequency of parental consanguinity, sib occurrence with normal parents, and normal mean paternal age at birth, suggest that most cases of O.I. type II represent autosomal recessive traits. Some previously reported cases and the biochemical findings in one case suggest still further genetic heterogeneity.

To further characterize the clinical, radiographic and chondro-osseous morphologic changes in the Desbuquois syndrome, 7 patients from three sibships are described. They all had prenatal onset severe rhizomelic and mesomelic shortness with marked joint laxity and marked micrognathia. Radiographic changes were distinct, consisting of a supernumerary ossification center between the proximal phalanx of the index finger and the second metacarpal, and variable thumb changes. The femoral necks showed enlargement of the lesser trochanter with metaphyseal breaking, producing a characteristic "monkey wrench" (Swedish key) appearance. Growth plate cartilage showed dilated cisterns of rough endoplasmic reticulum in reserve zone chondrocytes. Three of the 7 cases were diagnosed prenatally by second trimester ultrasound and one case by fetoscopy. This syndrome exhibits significant phenotypic variability and must be differentiated from the Catel-Manzke syndrome which exhibits similar radiographic changes in the hands.