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[A patient with Kennedy-Alter-Sung syndrome showing cardiomyopathy]
T Hattori1, S Ikeda, K Yoshida
1Department of Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
Insights
Kennedy-Alter-Sung (KAS) syndrome, a genetic disorder, can cause dilated cardiomyopathy. This study identifies a link between androgen receptor gene abnormalities and cardiac muscle degeneration in KAS patients.
Area of Science:
- Neurology
- Cardiology
- Genetics
Background:
- Kennedy-Alter-Sung (KAS) syndrome is a rare genetic disorder characterized by progressive muscular atrophy and weakness.
- It is caused by an abnormal androgen receptor gene with an increased number of CAG tandem repeats.
Observation:
- A 31-year-old male patient with KAS syndrome presented with recent arrhythmia, gynecomastia, and proximal muscle weakness.
- Cardiac investigations revealed dilated cardiomyopathy, and myocardial biopsy showed cell degeneration.
Findings:
- Androgen receptor gene analysis confirmed increased CAG repeats, diagnosing KAS syndrome.
- The study establishes a causal relationship between androgen receptor gene abnormality and cardiac involvement in KAS syndrome.
Implications:
- Androgen receptor dysfunction, due to gene abnormality, can lead to myocardial involvement and cardiomyopathy in KAS patients.
- This research elucidates a previously unknown pathophysiology of cardiomyopathy associated with KAS syndrome.
Abstract:
A 31-year-old man with a history of progressive muscular atrophy and weakness from around 22 years of age, recently experienced arrhythmia. On examination he showed gynecomastia and slight proximal weakness in both upper and lower extremities. Androgen receptor gene analysis showed an increased number of tandem CAG repeats in exon 1, thus leading to a diagnosis of Kennedy-Alter-Sung (KAS) syndrome. Cardiological investigations including echocardiography, scintigraphy and catheterization disclosed dilated cardiomyopathy. Cardiac muscle biopsy showed myocardial cell degeneration. KAS syndrome is causatively related to androgen receptor gene abnormality. This receptor is widely distributed throughout human body, including the genital tract, spinal cord, liver, and heart. Androgen receptor dysfunction may induce cardiac muscle involvement in patients with KAS syndrome, producing the previously unknown pathophysiology of cardiomyopathy.