When 6 million Jewish people perish in concentration camps, it is called a Holocaust.
When 20 million people died in Stalin’s Soviet Union it was called ruthless Communist murder.
When PolPot murdered 1.8 million in Cambodia he was a madman.
When a million plus died in the fatricidal civil war between the Hutu’s and Tutsi’s in Rwanda and Burundi – we were horrified.
When close to a million died in rioting during partition, it was a human tragedy.

when 60 million girls go missing what do you call it?

The UNFPA report of 2005 makes for scary reading. It states that 60 million girls are missing in Asia.

Discrimination against girls may begin in the womb. In some countries, a strong preference for sons has led to the elimination of millions of girls through prenatal sex selection. Baby girls also die through deliberate neglect and starvation. In Asia, at least 60 million girls are “missing”.

In Chapter 7 dealing with Geneder Based Violence the report also states:

Worldwide, an estimated one in five women will be a victim of rape or attempted rape in her lifetime.One in three will have been beaten, coerced into sex or otherwise abused, usually by a family member or an acquaintance. More often than not, the perpetrators go unpunished. Each year, hundreds of thousands of women and children are trafficked and enslaved, millions more are subjected to harmful practices. Violence kills and disables as many women between the ages of 15 and 44 as cancer. And its toll on women’s health surpasses that of traffic accidents and malaria combined.

If 60 million Tamils, or Muslims, or Slavs or Jews or Yadavs or Todas or Bedu’s or Kurds disappeared it would be front page news. But, when 60 million girls disappear, it seems to be par for the course.