Monilethrix

Monilethrix (also referred to as beaded hair) is a rare autosomal dominant hair disease that results in short, fragile, broken hair that appears beaded. It comes from the Latin word for necklace (monile) and the Greek word for hair (thrix). [Source: Wikipedia ]

OrphaNet reference
Monilethrix 
May Cause
Eyebrow anomaly
Sparse eyebrows