Source The Telegraph
Seventeen British sperm donors have fathered more than 500 children between them, new figures show.
The startling numbers have led to fears that men could be unknowingly passing defective DNA to dozens of youngsters, because currently donors are not screened for faulty genes such as BRCA1/2 which increase the risk of ovarian and breast cancer.
It also raises the risk that siblings could unexpectedly meet and form relationships without realising they are related.
Although more than 18,000 children have been born who have at least nine other half-brothers or sisters, just 163 have registered on the Human Fertilisation and Embryology Authority (HFEA) Donor Sibling Link, which attempts to reunite them.