Early onset of cardiomyopathy and intellectual disability in a girl with Danon disease associated with a de novo novel mutation of the LAMP2 gene

We describe a girl with Danon disease who presented with hypertrophic cardiomyopathy and Wolff‐Parkinson‐White (WPW) syndrome at 12 years of age. Subsequently, she showed signs of mild learning disability and intellectual disability on psychological examinations. She had a de novo novel mutation in the LAMP‐2 gene and harbored an identical c.749C > A (p.Ser250X) variant, resulting in a stop codon in exon 6. She showed decreased, but not completely absent LAMP‐2 expression on immunohistochemical and Western blot analyses of a skeletal muscle biopsy specimen, which has been suggested to be caused by a 50% reduction in LAMP‐2 expression (LAMP‐2 haploinsufficiency) in female patients with Danon disease caused by a heterozygous null mutation. To our knowledge, our patient is one of the youngest female patients to have been given a diagnosis of Danon disease. In addition, this is the first documented case in a girl that was clearly associated with intellectual disability, which is very rare in females with Danon disease. Our findings suggest that studies of female patients with Danon disease can extend our understanding of the clinical features of this rare disease.

Source: Neuropathology - March 31, 2016 Category: Neurology Authors: Kazuma Sugie, Hiroyuki Yoshizawa, Kenji Onoue, Yoko Nakanishi, Nobuyuki Eura, Megumu Ogawa, Tomoya Nakano, Yasuhiro Sakaguchi, Yukiko K. Hayashi, Toshifumi Kishimoto, Midori Shima, Yoshihiko Saito, Ichizo Nishino, Satoshi Ueno Tags: Case Report Source Type: research