Lenz-Majewski syndrome.

Lenz-Majewski syndrome is a rare disorder of unknown etiology. The condition is characterized by a disproportionately large head with large fontanels and widely separated sutures that close late. The head appears large relative to the reduced size of the trunk and limbs. The skin is loose, wrinkled, and atrophic with prominent veins, especially in the scalp. The ears are large and floppy, and frequently there is choanal atresia or stenosis, nasolacrimal duct obstruction, and, in boys, cryptorchidism and inguinal hernia. The disorder is characterized by failure to thrive and mental retardation. In contrast to craniometaphyseal and craniodiaphyseal dysplasias, the conditions most likely to be mistaken for this disorder, there does not appear to be any impingement on cranial nerves. The skeletal alterations are striking. The radiographic features include progressive sclerosis of the skull, facial bones, and vertebrae; broad clavicles and ribs; short or absent middle phalanges; diaphyseal undermodeling and midshaft cortical thickening; metaphyseal and epiphyseal hypostosis; and retarded skeletal maturation. Tooth enamel is also defective.