Gender testing to help avoid genetic diseases

The new test will try to identify the healthiest sperm Keystone

A new test called Microsort will allow couples with certain serious hereditary disorders to choose the sex of their baby in order to reduce the chance of passing on an active form of their disease.

The test, developed in the United States, will be offered by the University of Basel starting in July, said a report in the Basler Zeitung newspaper confirmed by the university. Basel will likely be the only location in continental Europe to offer the test in the foreseeable future.

The test is based on the principle that sperm with the female X chromosome contain more genetic material than sperm with the male Y chromosome. Using Microsort to sort the sperm, the sex of a child can be predicted with a reliability of 80 per cent.

Because certain hereditary diseases affect one sex more than the other, the test can be used to choose sperm which will produce a child of the unaffected sex. Some diseases, for example, are active in male children, whereas females carry the disease without showing its effects.

Currently, some women in Switzerland who suffer from genetic diseases terminate multiple pregancies in an attempt to become pregnant with a child which is not affected by their disease. Genetic testing is allowed in Switzerland only after a baby has been conceived.

Pre-implantation genetic diagnosis – a procedure which tests embryos before implantation – is forbidden in Switzerland.

Swiss law allows gender selection of sperm only in cases in which one or both parents suffer from a genetic disease.