Rs1801133
Encyclopedia
C677T or rs1801133 is a genetic variation—a single nucleotide polymorphism
(SNP)—in the MTHFR gene
.
Among Americans the frequency of T-homezygosity ranges from 1% or less among Blacks to 20% or more among Italians and Hispanics.
It has been related to
In 2000 association studies on oral clefts, Down syndrome
, and fetal anticonvulsant syndrome were either unreplicated or had yielded conflicting results.
Studies have investigated the combined effect of C677T and A1298C.
Single nucleotide polymorphism
A single-nucleotide polymorphism is a DNA sequence variation occurring when a single nucleotide — A, T, C or G — in the genome differs between members of a biological species or paired chromosomes in an individual...
(SNP)—in the MTHFR gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Among Americans the frequency of T-homezygosity ranges from 1% or less among Blacks to 20% or more among Italians and Hispanics.
It has been related to
- schizophreniaSchizophreniaSchizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
- Alzheimer's diseaseAlzheimer's diseaseAlzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
- depression
- autismAutismAutism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
- spina bifidaSpina bifidaSpina bifida is a developmental congenital disorder caused by the incomplete closing of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through...
.
In 2000 association studies on oral clefts, Down syndrome
Down syndrome
Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...
, and fetal anticonvulsant syndrome were either unreplicated or had yielded conflicting results.
Related genetic variants
A1298C is a SNP in the same gene.Studies have investigated the combined effect of C677T and A1298C.