The Food and Drug Administration is expected to approve a new gene therapy drug from pharmaceutical company Novartis by the end of May.  

• Zolgensma is a treatment for spinal muscular atrophy

• Hundreds of children are born in the United States each year with the genetic, muscle-wasting disorder that kills many sufferers before they reach their second year

• Industry analysts expect the price for the single-treatment therapy to be from $1.5 million to $5 million

• Insurance companies might be reluctant to cover the drug

• Zolgensma represents a coming wave of gene therapy drugs that likely will carry whopping price tags