Oto-palato-digital syndrome, type II: report of three cases with further delineation of the chondro-osseous morphology.

Oto-palato-digital syndrome type II (OPD II) is a lethal X-linked skeletal dysplasia with pleiotropic manifestations. The basic defect is not known. There has been only one detailed report of the chondro-osseous abnormalities in this condition describing abnormal periosteal ossification in a single case [1990: Am J Med Genet 36:226-231]. We report on three cases of OPD II emphasizing the chondro-osseous morphology. Although endochondral ossification was normal, periosteal ossification was defective with islands of cortical bone aplasia and hyperplasia of the periosteum. The trabecular bone was also extremely poorly formed and markedly hypercellular. Both membranous ossification and bone remodeling appear to be defective in OPD II and should account for part of the observed phenotype. The biglycan gene maps to Xq28 and is involved in bone formation, but was excluded as a candidate by direct sequencing of cDNA in one case.

Syndrome of multiple pterygia, camptodactyly, facial anomalies, hypoplastic lungs and heart, cystic hygroma, and skeletal anomalies: delineation of a new entity and review of lethal forms of multiple pterygium syndrome.

Three unrelated stillborn infants (cases 1-3) are presented here with a distinct constellation of multiple anomalies: namely, multiple pterygia involving chin-to-sternum, cervical, axillary, antecubital, crural and/or popliteal areas, flexion contractures of multiple joints, small chest, hydrops, characteristic abnormal facial appearance with hypertelorism, markedly flattened nasal bridge with hypoplastic nasal alae, cleft palate, micrognathia, apparently low-set malformed ears, short neck with a cystic hygroma at the back of the neck and head, and pulmonary and cardiac hypoplasia. Radiographic studies, in addition, showed scalp edema, microbrachycephaly, flattened mandibular angle, lack of normal curvature at the cervico-thoracic junction, marked bony fusion of posterior spinous processes of older fetuses (cases 1, 2), thin crowded ribs, markedly hypoplastic scapulae, hypoplastic iliac wings, ischia and pubic bones, undermodeling of tubular bones, and radio-ulnar synostosis. Histologic studies of the skeletal system showed cartilaginous and bony fusion of the spinous processes (cases 1, 2), fusion of epiphyseal cartilages of distal humerus and proximal ulna, a poorly developed joint space, an abnormal growth plate, and weak safranin staining of the resting cartilages (cases 1, 2). To the best of our knowledge, this pattern of anomalies constitutes a previously undescribed syndrome. Prenatal diagnosis of this entity is possible by ultrasonographic studies on the basis of nonimmune fetal hydrops, a cystic hygroma at the back of the head and neck, diminished fetal activity, short and fixed limbs, and/or maternal hydramnios. Three additional cases (cases 4-6) are also presented to show a possible heterogeneity of this syndrome.

Odontoid hypoplasia with vertebral cervical subluxation and ventriculomegaly in metatropic dysplasia.

Our experience with 12 patients with metatropic dysplasia has demonstrated two important and treatable complications: odontoid hypoplasia with subluxation of the first and second cervical vertebrae, and ventriculomegaly. Hypoplasia and lack of ossification of the odontoid process were noted in all cases. Subluxation of these two vertebrae was demonstrated in all six patients who had lateral flexion-extension radiographs; three had subluxation even in a neutral position, and sudden odontoid dislocation developed in another after a simple fall. Four individuals have had surgical fusion of the cervical vertebrae; one child died suddenly, 1 week before scheduled surgery. In the three patients in whom computed tomography scans of the head were obtained, enlarged ventricles were found; one had symptomatic increased intracranial pressure and required a shunt. We recommend that odontoid hypoplasia be evaluated in all patients with metatropic dysplasia. If subluxation is proved, atlantoaxial fusion should be performed before damage to the cervical part of the spinal cord results. Serial head circumference measurements and evaluation for hydrocephalus are also recommended.

An embedding method for histochemical studies of undecalcified skeletal growth plate.

We have used glycol methacrylate to study undecalcified skeletal growth plate and subchondral bone. Minor modifications of the original technique including dehydration in glycol methacrylate vacuum infiltration and polymerization in the cold make it quite suitable for embedding of such tisssues. Moreover, specimens can be processed quickly and the morphologic and biochemical integrity of the tissue retained so that histochemical procedures can be readily applied. Collagen, glycosaminoglycan, glycogen, lipid, calcium and the activity of alkaline and acid phosphatase were localized. This technique appears to be very useful for studying skeletal tissues.

An oculocerebrofacial syndrome.

A syndrome of mental retardation, microcephaly, a mongoloid slant to the palpebral fissures, microcornea, strabismus, myopia, optic atrophy, high-arched palate, preauricular skin tags and small mandible is described in four (including one set of twins) of seven sibs born to unaffected, nonconsanguineous parents of German ancestry. An autosomal recessive mode of inheritance seems most likely.

The Morquio syndrome (mucopolysaccharidosis IV): Morphologic and biochemical studies.

The Morquio syndrome (mucopolysaccharidosis IV) is a lysosomal storage disease characterized clinically by dwarfism, corneal opacities, dental abnormalities, cardiopulmonary complications, normal intelligence, dysostosis multiplex with universal platyspondyly, and excessive urinary excretion of keratosulfate. The purpose of this communication is to report morphologic observations of Morquio skin and cartilage, and biochemical studies of cultured fibroblasts and cartilage-derived cells. Cells of the basal and Malpighian layers of the epidermis contain large single-membrane-bound vacuoles whereas other dermal cells types are normal. Chondrocytes are packed with similar vacuoles. Preliminary studies of mucopolysaccharide (MPS) metabolism of cultured Morquio cartilage-derived cells and fibroblasts reveals excessive intracellular MPS accumulation in cartilage-derived cells but only modest accumulations in fibroblasts. The Morquio syndrome appears to be a cell-type specific MPS storage disorder, and further studies to elucidate the presumed deficiency of lysosomal hydrolase(s) should be directed at tissues displaying both morphologic and metabolic abnormalities.

Alkaline and acid phosphatase demonstration in human bone and cartilage: effects of fixation interval and methacrylate embedments.

Human bone and cartilage specimens were evaluated for acid and alkaline phosphatase localization following varying fixation periods for fresh or frozen tissue. Formalin fixations of up to 183 hr were followed by embedment in methyl methacrylate; frozen tissue was examined either without fixation or following fixation for up to 1 hr and subsequent glycol or methyl methacrylate embedding. The humeral epiphysis of a young patient with osteogenic sarcoma showed optimum acid and alkaline phosphatase localization following fixation for periods up to 15 hr and embedding in methyl methacrylate. Frozen costochondral junction from a newborn with osteogenesis imperfecta type II showed optimum acid and alkaline phosphatase localization following 30 min fixation in formalin and embedding in methyl methacrylate or after 5 min fixation and embedding in glycol methacrylate.