Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that occurs when pancreatic cells are destroyed by the body's immune system. In healthy persons, beta cells produce insulin. Insulin is a hormone required by the body to store and convert blood sugar into energy. T1D results in high blood sugar levels in the body prior to treatment. Common symptoms include frequent urination, increased thirst, increased hunger, weight loss, and other complications. Additional symptoms may include blurry vision, tiredness, and slow wound healing. While some cases take longer, symptoms usually appear within weeks or a few months.
Chromosome 6 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 6 spans nearly 171 million base pairs and represents between 5.5 and 6% of the total DNA in cells. It contains the major histocompatibility complex, which contains over 100 genes related to the immune response, and plays a vital role in organ transplantation.
In genetics, the transmission disequilibrium test (TDT) was proposed by Spielman, McGinnis and Ewens (1993) as a family-based association test for the presence of genetic linkage between a genetic marker and a trait. It is an application of McNemar's test.
Non-obese diabetic or NOD mice, like biobreeding rats, are used as an animal model for type 1 diabetes. Diabetes develops in NOD mice as a result of insulitis, a leukocytic infiltrate of the pancreatic islets. The onset of diabetes is associated with a moderate glycosuria and a non-fasting hyperglycemia. It is recommended to monitor for development of glycosuria from 10 weeks of age; this can be carried out using urine glucose dipsticks. NOD mice will develop spontaneous diabetes when left in a sterile environment. The incidence of spontaneous diabetes in the NOD mouse is 60–80% in females and 20–30% in males. Onset of diabetes also varies between males and females: commonly, onset is delayed in males by several weeks. The mice are known to carry IgG2c allele.
HLA-DR is an MHC class II cell surface receptor encoded by the human leukocyte antigen complex on chromosome 6 region 6p21.31. The complex of HLA-DR and peptide, generally between 9 and 30 amino acids in length, constitutes a ligand for the T-cell receptor (TCR). HLA were originally defined as cell surface antigens that mediate graft-versus-host disease. Identification of these antigens has led to greater success and longevity in organ transplant.
HLA-DQ (DQ) is a cell surface receptor protein found on antigen-presenting cells. It is an αβ heterodimer of type MHC class II. The α and β chains are encoded by two loci, HLA-DQA1 and HLA-DQB1, that are adjacent to each other on chromosome band 6p21.3. Both α-chain and β-chain vary greatly. A person often produces two α-chain and two β-chain variants and thus 4 isoforms of DQ. The DQ loci are in close genetic linkage to HLA-DR, and less closely linked to HLA-DP, HLA-A, HLA-B and HLA-C.
HLA-DQ9 (DQ9) is a human leukocyte antigen serotype within the HLA-DQ (DQ) serotype group. DQ9 is a split antigen of the DQ3 broad antigen. DQ9 is determined by the antibody recognition of β9 and this generally detects the gene product of DQB1*0303.
Calpain-10 is a protein that in humans is encoded by the CAPN10 gene.
Large proline-rich protein BAT2 is a protein that in humans is encoded by the BAT2 gene.
Forkhead box protein N3 is a protein that in humans is encoded by the FOXN3 gene.
Complement C4-A is a kind of the Complement component 4 protein that in humans is encoded by the C4A gene.
HLA A1-B8-DR3-DQ2 haplotype is a multigene haplotype that covers a majority of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles; common multigene haplotypes are generally the result of descent by common ancestry. Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.
HLA A1-B8 is a multigene haplotype that covers the MHC Class I region of the human major histocompatibility complex on chromosome 6. A multigene haplotype is set of inherited alleles covering several genes, or gene-alleles; common multigene haplotypes are generally the result of identity by descent from a common ancestor. Chromosomal recombination fragments multigene haplotypes as the distance to that ancestor increases in number of generations.
The dog leukocyte antigen (DLA) is a part of the major histocompatibility complex (MHC) in dogs, encoding genes in the MHC. The DLA and MHC system are interchangeable terms in canines. The MHC plays a critical role in the immune response system and consists of three regions: class I, class II and class III. DLA genes belong to the first two classes, which are involved in the regulation of antigens in the immune system. The class II genes are highly polymorphic, with many different alleles/haplotypes that have been linked to diseases, allergies, and autoimmune conditions such as diabetes, polyarthritis, and hypothyroidism in canines.
Neonatal diabetes mellitus (NDM) is a disease that affects an infant and their body's ability to produce or use insulin. NDM is a kind of diabetes that is monogenic and arises in the first 6 months of life. Infants do not produce enough insulin, leading to an increase in glucose accumulation. It is a rare disease, occurring in only one in 100,000 to 500,000 live births. NDM can be mistaken for the much more common type 1 diabetes, but type 1 diabetes usually occurs later than the first 6 months of life. There are two types of NDM: permanent neonatal diabetes mellitus (PNDM), a lifelong condition, and transient neonatal diabetes mellitus (TNDM), a form of diabetes that disappears during the infant stage but may reappear later in life.
MODY 6 or NEUROD1-MODY is a form of maturity onset diabetes of the young.
Most cases of type 2 diabetes involved many genes contributing small amount to the overall condition. As of 2011 more than 36 genes have been found that contribute to the risk of type 2 diabetes. All of these genes together still only account for 10% of the total genetic component of the disease.
CDKAL1 is a gene in the methylthiotransferase family. The complete physiological function and implications of this have not been fully determined. CDKAL1 is known to code for CDK5, a regulatory subunit-associated protein 1. This protein CDK5 regulatory subunit-associated protein 1 is found broadly across tissue types including neuronal tissues and pancreatic beta cells. CDKAL1 is suspected to be involved in the CDK5/p35 pathway, in which p35 is the activator for CDK5 which regulates several neuronal functions.
In recent years it has become apparent that the environment and underlying mechanisms affect gene expression and the genome outside of the central dogma of biology. It has been found that many epigenetic mechanisms are involved in the regulation and expression of genes such as DNA methylation and chromatin remodeling. These epigenetic mechanisms are believed to be a contributing factor to pathological diseases such as type 2 diabetes. An understanding of the epigenome of diabetes patients may help to elucidate otherwise hidden causes of this disease.
In Japan, there are an estimated 11 million people with diabetes in 2021. Like much of the developed world, cases of diabetes in Japan have increased in recent times from an estimated 6.9 million people affected in 1997, to around 8.9 million in 2007, to over 11 million today.
