SGCE and myoclonus-dystonia syndrome: Distinguishing BHC from DYT11-myoclonus-dystonia syndrome (due to mutations in the SGCE gene) can also be difficult.60 Asmus et al.62 attempted to identify clinical criteria differentiating BHC from genetically proven myoclonus-dystonia and concluded that early onset hypotonia, chorea in infancy, and possible association with thyroid or lung disease were good clues for differentiating BHC from this similar genetic movement disorder.