Fragile X syndrome Fragile X syndrome is a genetic disease that most commonly causes intellectual disability, behavioral problems, and physical abnormalities. Symptoms vary widely from patient to patient. The syndrome is also referred to as Martin Bell Syndrome (MBS) or Marker X syndrome. Physical characteristics It can give physical characteristics like an elongated face, large … Continue reading Fragile X syndrome (FXS) or Martin Bell Syndrome (MBS) causes intellectual disability, behavioral problems, and physical abnormalities