Homozygous thermolabile variant of the methylenetetrahydrofolate reductase gene: a potential risk factor for hyperhomocysteinaemia, CVD, and stroke in childhood.
In this study of 118 children (median age 5.1 years; range 6 months to 17 years) with ischaemic stroke or transient ischaemic attack (TIA), 22 children (19%) were homozygous for the thermolabile variant of the methylenetetrahydrofolate reductase allele (t-MTHFR), compared with nine of 78 (12%) of a reference population (p=0.18, OR 1.76, 95% CI 0.76 to 4.04). Of those with cerebrovascular disease (CVD), 17 of 84 were homozygous for the t-MTHFR allele (p=0.13 compared with the reference population (OR 1.95, 95% CI 0.81 to 4.65). There was a significant (p<0.025) increment of plasma total homocysteine concentration in homozygotes for the t-MTHFR allele compared with heterozygotes, negatives for the t-MTHFR allele, and control children with no history of stroke. In four of 12 homozygotes for the t-MTHFR allele, plasma homocysteine levels were raised, compared with three of 38 of those who were negative or heterozygous (p=0.047; OR 5.8, 95% CI 1.1 to 31.2). Homozygotes for the t-MTHFR allele were significantly more likely to have a recurrent event than those who were negative or heterozygous (Cox regression p=0.031, hazard ratio 2.18, 95% CI 1.08 to 4.42). These data suggest that homozygosity for the t-MTHFR allele is associated with raised homocysteine levels in children and is a risk factor for primary and secondary stroke and TIA.
Prengler
M
M
Neurosciences Unit, Institute of Child Health, University College London, UK.
Sturt
N
N
Krywawych
S
S
Surtees
R
R
Liesner
R
R
Kirkham
F
F
D000293:Adolescent; D000483:Alleles; D002561:Cerebrovascular Disorders / Q000097:blood / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D006710:Homocysteine / Q000097:blood*; D006720:Homozygote; D006801:Humans; D007223:Infant; D002546:Ischemic Attack, Transient / Q000097:blood / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000235:genetics*; D013696:Temperature
D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)