Electron Microscopic and Immunohistochemical Findings of the Epidermal Basement Membrane in Two Families with Nail-patella Syndrome

• Main Authors: Satoru Shinkuma, Hideki Nakamura, Manami Maehara, Shota Takashima, Toshifumi Nomura, Yasuyuki Fujita, Satoshi Hasegawa, Kazuko C. Sato-Matsumura, Riichiro Abe, Hiroshi Shimizu
• Format: Article
• Language: English
• Published: Society for Publication of Acta Dermato-Venereologica 2019-09-01
• Series: Acta Dermato-Venereologica
• Subjects: epidermal basement membrane; glomerular basement membrane; hereditary osteo-onychodysplasia; lim-homeodomain protein; lim-homeobox transcription factor 1ß; lmx1b; type iv collagen
• Online Access: https://www.medicaljournals.se/acta/content/html/10.2340/00015555-3318

Nail-patella syndrome is an autosomal dominant disorder characterized by nail dysplasia and skeletal anomaly. Some patients have been shown to have ultrastructural abnormalities of the glomerular basement membrane that result in nephrosis. However, little has been reported on the epidermal basement membrane in this condition. This paper reports 2 families with nail-patella syndrome. Direct sequencing analysis of LMX1B revealed that family 1 and family 2 were heterozygous for the mutations c.140-1G>C and c.326+1G>C, respectively. To evaluate the epidermal basement membrane zone, ultrastructural and immunohistochemical analyses were performed using skin specimens obtained from the dorsal thumb. Electron microscopy showed intact hemidesmosomes, lamina lucida, lamina densa, and anchoring fibrils. Immunofluorescence studies with antibodies against components of the epidermal basement membrane zone revealed a normal expression pattern among the components, including type IV collagen. These data suggest that nail dysplasia in patients with nail-patella syndrome is not caused by structural abnormalities of the epidermal basement membrane.