Description:
Current
State of the Art:
Type 1 diabetes is an organ-specific autoimmune disease with
aberrant immune responses to specific β-cell autoantigens. Prevention is important because diabetes
interrupts normal development in children and carries the threat of severe
complications in the most active period of life. Both environmental and genetic factors
play etiological roles. The most informative genetic locus, HLA class II,
confers about half of the total genetic risk, but has low positive predictive
value when used alone in the general population1. Autoantibodies provide a
practical readout of β-cell autoimmunity, are easily sampled in venous blood,
and have become a mainstay of type 1 diabetes prediction
efforts.
Disadvantages
with the Current Art:
Autoantibodies
are useful to detect developing type 1 diabetes in close relatives of diabetic
patients, whose risk is ∼3%.
However, most cases are sporadic rather than familial, necessitating general
population screening. This has been difficult in part because the observed
autoantibody prevalence greatly exceeds the low disease prevalence in
nonrelatives leading to high false-positive rates. As stated previously, the most
informative genetic locus, HLA class II, confers about half of the total genetic
risk, but has low positive predictive value when used alone in the general
population.
Advantages
of the Invention:
Through a genetic study of 944 multi-ethnic diabetes families, the
inventors have narrowed the human IDDM5 locus to a 180kb of genomic DNA on
chromosome 6q25. The inventors have
cloned and characterized a novel gene named SUMO4, which showed strong
homologies to the SUMO gene family.
SUMO4 confers susceptibility to human type 1 diabetes. This is an improvement on current
methods; the addition of the SUMO4 gene as a predictor of type 1 diabetes risk
to HLA genes enhances prediction risk because there is one more gene, SUMO4,
added to the group of existing predictive genes such as HLA.
Patent
Status: US Pat. Pub. No.
2007/0225480
Inventors:
Jin-Xiong She, Ph.D; Cong-Yi,
M.D.;
Case
Number: GHSU
2004-011