RÉSUMÉ
Two siblings, one male and one female, were noted to have a distinct skeletal dysplasia. The clinical and radiographic features resemble those observed in Kniest dysplasia and Rolland-Desbuquois syndrome, but important differences were noted. Specifically, these two patients have microstomia, "pursed" lips, and ectopia lentis, and their radiographs reveal no coronal clefts. Chondro-osseous features also differ from those observed in either of the other disorders. Scattered dense patches consisting of collagen fibers 10 to 30 times broader than normal are seen scattered throughout the cartilage matrix; the "Swiss cheese" appearance characteristic of Kniest dysplasia is not observed. These patients appear to have a new skeletal dysplasia, most likely inherited in an autosomal recessive fashion.
Sujet(s)
Dysplasies osseuses/génétique , Dysplasies osseuses/imagerie diagnostique , Dysplasies osseuses/anatomopathologie , Os et tissu osseux/ultrastructure , Cartilage/ultrastructure , Ectopie du cristallin/génétique , Femelle , Gènes récessifs , Humains , Nourrisson , Mâle , Microstomie/génétique , Radiographie , SyndromeRÉSUMÉ
Signs of myasthenia gravis developed by age 3 years in 11 children. Six of these patients had persistent neonatal myasthenia gravis, a familial abnormality of neuromuscular transmission that is not immunologically mediated. Five patients had juvenile onset myasthenia gravis, an autoimmune disorder similar to myasthenia gravis in adults. Autoimmune myasthenia has rarely been recognized by age 3 years, but the presence of five cases in our series suggests that the disorder may be more common in young children than once believed. The development of anti-acetylcholine receptor antibody assays makes it easier to distinguish autoimmune myasthenia gravis from the congenital forms. This distinction is important, because the prognosis, treatment, and risk of recurrence in family members is different for each type of myasthenia.