ⓘ Common disease-common variant. The common disease-common variant hypothesis predicts that common disease-causing alleles, or variants, will be found in all huma ..

                                     

ⓘ Common disease-common variant

The common disease-common variant hypothesis predicts that common disease-causing alleles, or variants, will be found in all human populations which manifest a given disease. Common variants are known to exist in coding and regulatory sequences of genes. According to the CD-CV hypothesis, some of those variants lead to susceptibility to complex polygenic diseases. Each variant at each gene influencing a complex disease will have a small additive or multiplicative effect on the disease phenotype. These diseases, or traits, are evolutionarily neutral in part because so many genes influence the traits. The hypothesis has held true in the case of putative causal variants in apolipoprotein E, including APOE ε4, associated with Alzheimers disease. IL23R has been found to be associated with Crohns disease; the at-risk allele has a frequency 93% in the general population.

One common form of variation across human genomes is called a single nucleotide polymorphism SNP. As indicated by the name, SNPs are single base changes in the DNA. SNP variants tend to be common in different human populations. These polymorphisms have been valuable as genomic signposts, or "markers", in the search for common variants that influence susceptibility to common diseases. Research has linked common SNPs to diseases such as type 2 diabetes, Alzheimers, schizophrenia and hypertension.

                                     
  • Variant Creutzfeldt Jakob disease vCJD is a type of brain disease within the transmissible spongiform encephalopathy family. Symptoms include psychiatric
  • The common cold, also known simply as a cold, is a viral infectious disease of the upper respiratory tract that primarily affects the nose. The throat
  • have been suspected of acting independently or along with common variants to cause disease states. Allele frequency Exome sequencing Functional genomics
  • blindness, or seizures may also occur. There exists a less common variant of Canavan disease which is generally much less serious, and involves later onset
  • recessive. It is the most common form of a group of disorders called the neuronal ceroid lipofuscinoses NCLs Although Batten disease is usually regarded
  • are years the disease has gone undetected because of misdiagnoses. Biallelic pathogenic variants in the HEXB gene cause Sandhoff disease The gene provides
  • infectiosum or fifth disease is one of several possible manifestations of infection by parvovirus B19. The name fifth disease comes from its place
  • microvascular angina, i.e. angina caused by disease of the heart s small arteries. Some key features of variant angina are chest pain that is concurrently
  • Morocco, Algeria and Tunisia. A closely related variant lives in eastern Asia including Japan. The common toad is found at altitudes of up to 2, 500 metres