4. Usually apparent at birth, this disorder may manifest with abnormal or missing nails. Characteristic nail changes include triangular lunulae and, most prominently on the thumb and index fingers, hypoplasia. Also apparent are orthopedic changes (particularly affecting the knees and elbows), renal disease, and glaucoma.
Reprinted with permission from Cutis. 2000;66:71, 75-76.
Diagnosis: The osteo-onychodysplasia, or nail-patella syndrome, is an autosomal dominant disorder. Studies have linked the syndrome to chromosome 9q34 and identified point mutations in the LMX1B gene.4 Other kindreds have been linked to chromosome 17q21-22.5 Prenatal diagnosis is possible, including noninvasive prenatal diagnosis using ultrasonography. Because of the risk for glaucoma, all family members should be screened by an ophthalmologist.6
4. Seri M, Melchionda S, Dreyer S, et al. Identification of LMX1B gene point mutations in Italian patients affected with nail-patella syndrome. Int J Mol Med. 1999;4:285-290.
5. Mangino M, Sanchez O, Torrente I, et al. Localization of a gene for familial patella aplasia-hypoplasia (PTLAH) to chromosome 17q21-22. Am J Hum Genetics. 1999;65:441-447.
6. Lichter PR, Richards JE, Downs CA, et al. Cosegregation of open-angle glaucoma and the nail-patella syndrome. Am J Ophthalmol. 1997;124:506-515.
For more information on this case, see “What Is Your Diagnosis? Nail-Patella Syndrome.” Cutis. 2000;66:71, 75-76.