And because I like lists, I made a list of all gene therapies I could find currently in trials:

  * BlueBird Bio
  ** LentiGlobin
  *** β-thalassemia
  **** Phase I/II
  *** Sickle Cell Anemia
  **** Phase I/II
  ** Lenti-D
  *** Childhood Cerebral ALD
  *** Phase II/III
  * Sangamo BioSciences
  ** SB-728
  *** HIV/AIDS
  *** Phase II
  ** SB-313
  *** T-cell therapy for Glioblastoma Multiforme (GBM)
  *** Phase I
  ** Hemophilia A + B
  *** Pre-clinical
  ** β-thalassemia
  *** Pre-clinical
  ** Sickle Cell Anemia
  *** Pre-clinical
  ** Huntington's Disease
  *** Pre-clinical
  ** Lysosomal Storage Disorders
  *** Pre-clinical
  ** Other Monogenic Disorders(?)
  *** R&D
  ** CERE-110
  *** Alzheimer's Disease
  *** Phase II
  * Voyager Therapeutics
  ** VY-AADC01
  *** Parkinson's Disease
  *** Phase I/II
  ** VY-FXN01
  *** Friedreich's Ataxia
  *** Pre-clinical
  ** VY-SOD101
  *** Monogenic ALS
  *** Pre-clinical
  ** VY-HTT01
  *** Huntington's Disease
  *** Pre-clinical
  * Genzyme
  ** AAV-sFLT GZ402663
  *** Age-related macular degeneration
  *** Phase I
  * uniQure
  ** Glybera
  *** Lipoprotein lipase deficiency (LPLD)
  *** Approved (EU, US pending)
  ** Hemophilia B
  *** Phase I
  ** Hemophilia A
  *** Pre-clinical
  ** Congestive Heart Failure
  *** Pre-clinical
  * Spark Therapeutics
  ** SPK-RPE65
  *** RPE65-Mediated inherited retinal dystrophies (IRDs)
  *** Phase III
  ** SPK-CHM
  *** Choroideremia
  *** Phase I/II
  ** Genable GTO38
  *** RHO-ADRP
  *** Pre-clinical
  ** Hemophilia B
  *** IND-Enabling
  ** Hemophilia A
  *** Pre-clinical