anyone ever use this rare snp program? my brain is not working well right now so have to re-read instuctions later.
http://www.ianlogan.co.uk/23andme/23andMe_index2.htm
I've never heard of that program before - looks interesting.
There is potentially so much information in rarely-appearing phenomena.
(I guess being a routine "outlier" leads me to have that point of view.
)
Although, 2% / 1 in 50 isn't so unusual.
Ian Logan wrote that having the heterozygous allele does not seem to cause obvious health problems, but being homozygous probably could (and thus there are very few people alive in the world who are - I saw one reference that said 3 cases had been reported, and incidence was <1 in 1,000,000, but I closed some windows and lost the page before I'd copied the url):
"A 'heterozygous result, such as 'AG' indicates a 'carrier' status, which would not be expected to give any symptoms
whereas, a 'homozygous result, such as 'AA' indicates a complete change in the protein, and a pathological change may occur."
from Wikipedia:
"People with hypermethioninemia often do not show any symptoms. Some individuals with hypermethioninemia exhibit learning disabilities,
mental retardation, and other neurological problems; delays in motor skills such as standing or walking; sluggishness; muscle weakness; liver problems; unusual facial features; and their breath, sweat, or urine may have a smell resembling boiled cabbage.
Hypermethioninemia can occur with other metabolic disorders, such as
homocystinuria,
tyrosinemia and
galactosemia, which also involve the faulty breakdown of particular molecules."
"Inherited hypermethioninemia that is not associated with other metabolic disorders can be caused by shortages in the enzymes that break down methionine. These enzymes are produced from the
MAT1A,
GNMT and
AHCY genes. The reactions involved in metabolizing methionine help supply some of the amino acids needed for protein production. These reactions are also involved in transferring methyl groups, consisting of a carbon atom and three hydrogen atoms, from one molecule to another (
transmethylation), which is important in many cellular processes."
"The
AHCY gene provides instructions for producing the enzyme
S-adenosylhomocysteine hydrolase. This enzyme converts the S-adenosyl homocysteine into the compound
homocysteine. Homocysteine may be converted back to methionine or into another amino acid,
cysteine.
A deficiency of any of these enzymes results in a buildup of methionine in the body, and may cause signs and symptoms related to hypermethioninemia."
http://en.wikipedia.org/wiki/Hypermethioninemia
Looks like they screen newborns for hypermethioninemia:
http://newbornscreeningcodes.nlm.nih.gov/nb/sc/condition/MET
Here are some tests for hypermethioninemia:
https://www.bcm.edu/geneticlabs/test_detail.cfm?testcode=2070 (looks like they are all genetic?)
Some info from
http://www.perkinelmergenetics.com/Hypermethioninemia.htm
"Testing
Newborn screening of a dried blood spot using tandem mass spectrometry reveals elevated levels of methionine, which should prompt testing plasma for amino acids, including homocysteine. Elevated methionine and homocysteine in plasma indicate CBS deficiency, while an isolated increase in methionine suggests hepatic methionine adenosyltransferase deficiency. In affected patients, the presence of homocystine in the urine is a consistent finding, especially after early infancy."
Blood test for methionine:
http://www.ucdenver.edu/academics/c...s/DiagnosticTests/BGLTests/Pages/BGLtsmq.aspx
Looks like amino acids urine tests check for methionine - such as this one:
http://www.greatplainslaboratory.com/home/eng/urine_amino_acid.asp