DM2 is caused by an unstable CCTG expansion in intron-1 of the ZNF9 gene.[9] Allele expansions range from 75 to 11,000 repeats (mean 5000; (Table 1). Because the CCTG repeat is too large to amplify by PCR, all expansionpositive individuals appear to be homozygous and are thus indistinguishable from unaffected truly homozygous controls. Family studies may distinguish true homozygotes from expansion carriers. Failure of the expanded allele to amplify, also referred to as ''blank allele,'' suggests a non-Mendelian inheritance pattern and provides evidence that a family carries a DM2 expansion or that paternity was misinterpreted.1-2-1 Expansion sizes in the blood of affected children are usually shorter than in their parents. Most affected American families can trace an affected ancestor to Germany or Poland and all are of European descent.[2]

ZNF9, also referred to as cellular nucleic acid-binding protein, contains 7 zinc-finger domains and is thought to be an RNA-binding protein. It is broadly expressed, with the highest expression in heart and skeletal muscle. Mutant ZNF9 RNA accumulates in numerous nuclear foci, similar to those in DM1, but with lower stability of the probe-target complex. Whether nuclear RNA foci contain the entire unprocessed ZNF9 transcript is unknown. As in

DM1, intranuclear foci bind specific RNA-binding proteins, leading to altered splicing of the insulin receptor and CLC1.[2]

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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