Is it recommended to screen a newborn whose mother and maternal grandfather have Factor V Leiden mutation?
The factor V leiden mutation is very common in the general population. Studies of Caucasians have shown that 2-7% are heterozygotes and about 0.1% are homozygotes. Almost all factor V mutation homozygotes and about 10% of heterozygotes experience at least one thrombotic event during their lifetime. I’m assuming the mother is homozygous for the mutation. If so, your patient would be an obligate heterozygote at least, with a possibility of being a homozygote if his father is also affected. Screening is not recommended until adulthood when the patients are able to actively decide if they want to be genetically tested, as many discriminatory factors come into play including military eligibility, insurance coverage, etc. For girls, screening would be recommended if/when they wish to become pregnant. If a boy was found to be homozygous, prophylactic heparin with things such as a femur fracture, etc. would be indicated. If a girl was found to be homozygous, prophylactic heparin during pregnan
