All of the following diseases are associated with trinucleotide repeat sequence except:
Rest of the options are associated with trinucleotide repeat sequence. Triple-repeat mutations (Allelic expansion disorders) Due to an increase in the number of nucleotide repeats above a ceain threshold Length of the nucleotide repeat often correlates with the severity of the disease Anticipation: When repeat length increases from one generation to the next, disease manifestations may worsen or be observed at an earlier age. Disease Repeats Clinical features Fragile X-Syndrome CGG Mental retardation, large ears and jaws, macroorchidism in males Myotonic Dystrophy (Chromosome 19) CTG Muscle loss, cardiac arrhythmia , cataracts , frontal balding Huntington&;s disease CAG Affective disorder Spinocerebellar ataxia type 1 CAG Progressive ataxia, dysahria, dysmetria Friedreich&;s ataxia GAA Progressive ataxia, dysahria , hyperophic cardiomyopathy Ref: Nelson textbook of Medical Physiology 21st edition Pgno: 647
Huntington's disease
Fredreich's ataxia
Myotonica dystrophy
Hereditary motor-sensory neuropathy
Genetic and genetic disorders