Nail-Patella Syndrome in a 76-Year-Old Woman: Multisystem Phenotype, Diagnostic Delay, and Clinical Implications

Abstract

Nail-patella syndrome (NPS) is a rare autosomal dominant multisystem disorder characterized by a variable combination of nail abnormalities, patellar hypoplasia or dysplasia, elbow involvement, and iliac horns, with possible renal, ophthalmological, neurological, and skeletal manifestations. Recognition may be substantially delayed when individual abnormalities are assessed separately or attributed to age-related and degenerative musculoskeletal disease. We report the case of a 76-year-old woman evaluated for progressive bilateral knee pain, gait impairment, and chronic multisite musculoskeletal symptoms. Congenital thumbnail abnormalities and long-standing restriction of elbow extension had been present since childhood. Suspicion of NPS was first raised at the age of 43 years after bilateral iliac horns were identified radiographically in one of her grandsons. Clinical examination demonstrated bilateral thumbnail hypoplasia with partial absence of the ulnar nail plate, triangular lunulae, reduced dorsal distal interphalangeal creases, bilateral fifth-finger flexion contractures, marked limitation of elbow extension with restricted pronation and supination, and clinically hypoplastic patellae. Bilateral Lester sign and glaucoma were also documented. Radiographic assessment revealed bilateral patellar hypoplasia, lateral displacement of the left patella, bilateral knee osteoarthritis, and characteristic bilateral iliac horns. Additional findings included bilateral hip osteoarthritis, lumbar degenerative changes, pes planus, a bifid configuration of the left fifth metatarsal, osteopenia, and sensory abnormalities. Walking pain was 70 mm on a 100-mm visual analogue scale, and the WOMAC score was 42/96. Following a 10-day rehabilitation program, walking pain decreased from 70 to 50 mm on the visual analogue scale, while the WOMAC total score improved from 42/96 to 37/96, indicating short-term symptomatic and functional improvement. Routine urinalysis showed no proteinuria or hematuria. Molecular testing for a pathogenic LMX1B variant was not performed. The diagnosis was established on the basis of the highly characteristic integrated clinical and radiographic phenotype. This case illustrates how NPS may remain incompletely recognized for decades despite congenital manifestations and emphasizes the clinical value of pattern recognition across multiple organ systems. In particular, the coexistence of characteristic nail changes, patellar abnormalities, elbow involvement, and bilateral iliac horns should prompt consideration of NPS and appropriate multidisciplinary surveillance.