A Patient with Myotonic Dystrophy Type 1 (DM1) Accompanied by Laryngeal and Renal Cell Carcinomas Had a Small CTG Triplet Repeat Expansion But No Somatic Instability in Normal Tissues

• Published in: Internal Medicine Vol. 41; no. 4; pp. 312 - 318
• Main Authors: KINOSHITA, Masanobu, OSANAI, Ryuichi, KIKKAWA, Masaru, ADACHI, Akiko, OHTAKE, Toshiyuki, KOMORI, Tetsuo, HASHIMOTO, Kohzo, ITOYAMA, Shinnji, MITARAI, Tetsuya, HIROSE, Kazuhiko
• Format: Journal Article
• Language: English
• Published: Tokyo The Japanese Society of Internal Medicine 01.04.2002; Japanese Society of Internal Medicine
• Subjects: (CTG)n triplet repeat; Anticipation, Genetic; Autopsy; Biological and medical sciences; Blotting, Southern; Carcinoma, Renal Cell - complications; Carcinoma, Renal Cell - genetics; Carcinoma, Squamous Cell - complications; Carcinoma, Squamous Cell - genetics; DNA, Neoplasm - analysis; double cancers; Genes, Tumor Suppressor; Humans; Kidneys; Laryngeal Neoplasms - complications; Laryngeal Neoplasms - genetics; Male; Medical sciences; Middle Aged; Myotonic Dystrophy - complications; Myotonic Dystrophy - genetics; Nephrology. Urinary tract diseases; non-somatic instability; Polymerase Chain Reaction; Trinucleotide Repeat Expansion - genetics; Tumors of the urinary system; Kidney disease; Human; Neuromuscular diseases; Nervous system diseases; Urinary system disease; Carcinoma; Respiratory disease; Myotonia; Repeated sequence; Triplet; Malignant tumor; Genetic determinism; Kidney; Genetic disease; Case study; Polymerase chain reaction; Myotonic dystrophy; ENT disease; Larynx; Larynx disease; Molecular biology; Southern blotting; Expansion
• ISSN: 0918-2918; 1349-7235
• DOI: 10.2169/internalmedicine.41.312

We examined (CTG)n lengths in various tissues from a 70-year-old man with myotonic dystrophy type 1 (DM1) who had a small 60-70 (CTG)n expansion in his leukocytes. He died of renal cell carcinoma 5 years after a total laryngectomy for laryngeal carcinoma. Southern blot and polymerase chain reaction analyses were done on tissues obtained at autopsy. In the various normal tissues, (CTG)n lengths were almost all the same size, whereas the renal cell carcinoma and metastatic tissues had longer lengths. When compared with the lengths in leukocytes about 5 years previously, (CTG)n lengths in the normal tissues were the same size. These findings suggest that both somatic instability and age-dependent (CTG)n expansion in DM1 patients with a small expansion may be less dominant than in patients with large expansions. (Internal Medicine 41: 312-318, 2002)