UPDATE 1-Sequenom says SEC probes Down Syndrome test

* Says SEC initiates probe related to Down Syndrome test

* Says company's internal investigation ongoing

* Shares down 8 percent

June 30 (Reuters) - Sequenom Inc (SQNM.O) said the U.S. Securities and Exchange Commission has initiated an investigation related to the company's Down Syndrome test SEQureDx, sending its shares down 8 percent.

In April, the San Diego-based company had delayed launch of the test, citing mishandling of research and development test data and results by an employee.

Sequenom said the company intends to cooperate completely with the regulator's investigation and the company's internal investigation was ongoing.

Shares of Sequenom were down 8 percent at $3.60 after the bell. They closed at $3.91 Tuesday on Nasdaq. (Reporting by Vidya L Nathan in Bangalore; Editing by Vinu Pilakkott)