Hereditary osteo-onychodysplasia



synonym: nail-patella syndrome, HOOD

Definition, clinical and x-ray picture
Nail-patella syndrome (hereditary osteoonychodysplasia).
 * Rare autosomal dominant hereditary disease (mutation gene in LMX1B on the 9th chromosome; role, among other things, in the morphogenesis of the glomerular basement membranes);
 * severe deformities (dystrophic changes) of the nails or their aplasia (most pronounced on the thumbs);
 * aplasia or hypoplasia patellae;
 * dysplastic changes of the skeleton elbow (cubitus valgus) and knee joint (genua valga) - often leading to dislocation of the head radius (and limitation of movement in the elbow) or dislocation of the patella;
 * outgrowths of the iliac blades ("iliac horns") + open iliac blades with protruding spina iliaca anterior superior (image of an "elephant ear");
 * spondylolisthesis, scoliosis;
 * pes equinovaris, congenital flat foot, abnormal pigmentation of the iris, in the 3rd-4th decade of nephropathy with renal failure (in about 1/3 of patients; preceded by proteinuria and hematuria).

Therapy

 * Symptomatic (correction of leg deformities, then possible dislocation of the patella).