“Huntington Disease”, Victor McKusick, “Mendelian Inheritance in Man”, 1966.

Huntington disease (HD) is an inherited neurodegenerative disease.  Huntington Disease is caused by a heterozygous expanded trinucleotide repeat (CAG)n, encoding glutamine. In normal individuals, the range of repeat numbers is 9 to 36. In those with HD, the repeat number is above 37.  Huntington Disease (HD) is on cytogenetic location 4p16.3 at genomic coordinate 4:3,074,681-3,243,960 and the screenshot is shown BELOW  of 169,280 bp (base pairs) length of DNA.