Discordant repeat size and phenotype in Kennedy syndrome

• Published in: Clinical genetics Vol. 53; no. 4; pp. 276 - 277
• Main Authors: Morrison, PJ, Mirakhur, M., Patterson, VH
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-04-1998; Blackwell
• Subjects: Biological and medical sciences; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Diagnosis, Differential; Female; Humans; Kennedy syndrome; Male; Medical sciences; Middle Aged; Muscular Atrophy - diagnosis; Muscular Atrophy - genetics; Neurology; Pedigree; Phenotype; Syndrome; Trinucleotide Repeats; triplet repeat size; X-linked bulbospinal neuronopathy; Human; Neuromuscular diseases; Nervous system diseases; Family study; Repeated sequence; Spinal amyotrophy; Genetic disease; Phenotype; Central nervous system disease; Kennedy maladie; Degenerative disease; Mutation; Spinal cord disease
• ISSN: 0009-9163; 1399-0004
• DOI: 10.1111/j.1399-0004.1998.tb02695.x

Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease.