ABSTRACT
SUMMARY: The evaluation of genu varum and intoeing in young toddlers is a frequent problem seen by the primary care physician and the orthopaedic surgeon. This report describes six nonwhite breast-fed toddlers with extreme genu varum. Clinical and radiographic findings were consistent with vitamin D-deficiency rickets. Within 3 to 6 months of the initiation of ergocalciferol treatment, reparative processes were evident on both radiographic and clinical examinations. Laboratory studies also showed underlying correction. With the current emphasis on the benefits of breast-feeding and the limitation of sunlight, this diagnosis must remain on the differential in the evaluation of genu varum.
Subject(s)
Breast Feeding/adverse effects , Child Nutrition Disorders/etiology , Rickets/etiology , Vitamin D Deficiency/etiology , Vitamin D/analogs & derivatives , Black or African American , Black People , Child Nutrition Disorders/blood , Child Nutrition Disorders/diagnostic imaging , Child Nutrition Disorders/drug therapy , Child Nutritional Physiological Phenomena , Child, Preschool , Diagnosis, Differential , Ergocalciferols/therapeutic use , Female , Humans , Infant , Nutrition Policy , Nutritional Requirements , Radiography , Rickets/blood , Rickets/diagnostic imaging , Rickets/drug therapy , Socioeconomic Factors , Vitamin D/blood , Vitamin D Deficiency/blood , Vitamin D Deficiency/diagnostic imaging , Vitamin D Deficiency/drug therapyABSTRACT
The etiology of familial idiopathic scoliosis remains in question. The role of genetic factors in the development of this disorder has been well-documented; however, reports of the specific mode of genetic inheritance are inconclusive. These facts, combined with the phenotypic variability of this disorder, suggest that the genetic expression if idiopathic scoliosis may be dependent upon multiple factors and genetic interactions. Strategies to resolve the complex nature of this condition include genome-wide scanning of one extensive family or, alternatively, a well-characterized population of families affected with idiopathic scoliosis.
Subject(s)
Genetic Linkage/genetics , Scoliosis/genetics , Genetic Predisposition to Disease , Genome, Human , Humans , PhenotypeABSTRACT
To assess its possible role in the etiology of adolescent idiopathic scoliosis, the elastic fiber system of the ligamentum flavum was examined in twenty-three patients who had scoliosis and in five age-matched individuals who did not. Elastic fibers are composed of two components: the amorphous core of elastin and microfibrils, of which fibrillin is the primary element. Fresh-frozen histological specimens of ligamentum flavum removed at the time of an operation were examined by Verhoeff staining for elastic fibers and by immunohistochemical staining with use of a monoclonal antibody to fibrillin. Additionally, cultures of fibroblast cells from the ligamentum flavum were used to study the biosynthesis and secretion of fibrillin and its incorporation into the extracellular matrix in vitro. The specimens from one patient did not provide sufficient material for the histological studies; however, fibroblasts were harvested from this specimen. In five (23 percent) of the remaining twenty-two specimens from patients who had adolescent idiopathic scoliosis, Verhoeff staining of elastic fibers showed a marked decrease in fiber density (the number of fibers per unit area) and a non-uniform distribution of fibers throughout the ligament. Eighteen specimens (82 percent) exhibited abnormalities on immunohistochemical staining, including a marked disarrangement of the fibers and a difference in the density of staining, when compared with the control specimens from individuals who did not have adolescent idiopathic scoliosis. Studies of the biosynthesis and secretion of fibrillin and its incorporation into the extracellular matrix in vitro demonstrated that fibroblasts from four (17 percent) of the twenty-three specimens produced normal amounts of fibrillin and secreted it from the cell, but the fibrillin failed to bind to other macromolecules, to form a sedimentable complex, and to incorporate into the extracellular matrix. Collectively, the results suggest the potential role of the elastic fiber system as a component in the pathogenesis of adolescent idiopathic scoliosis in some individuals.
