Eiko Amo, Takafumi Toyohara, Naoya Saijo, Satoko Sato, Jun Takayama, Yoshiko Suto, Yuji Noguchi, Sosuke Kinomura, Yusuke Ishizuka, Shun Watanabe, Koichi Kikuchi, Rui Makino, Mai Yoshida, Yuji Oe, Tasuku Nagasawa, Koji Okamoto, Takehiro Suzuki, Mariko Miyazaki, Shinya Kawaguchi, Takashi Suzuki, Takaaki Abe, Shigeo Kure, Atsuo Kikuchi, Tetsuhiro Tanaka
Edema requires management tailored to its underlying etiology; however, in some cases the cause remains elusive. We describe a 79-year-old woman with lifelong unexplained peripheral edema. Comprehensive evaluation excluded common etiologies such as heart failure, renal dysfunction, and venous thrombosis. Whole-genome sequencing identified a novel homozygous splice-site variant (NM_018676.4:c.58+2T>G) in the thrombospondin-1 domain-containing protein 1 (THSD1) gene, which has previously been associated with non-immune hydrops fetalis (NIHF). This report describes, to our knowledge, the first elderly patient with chronic peripheral edema harboring a likely pathogenic THSD1 variant, suggesting that THSD1-related disease may, in rare instances, persist beyond the perinatal period and present into late adulthood. Although causality cannot be established definitively from a single case, the findings highlight the potential utility of genetic testing in adults with chronic unexplained edema.