coloboma of macula-brachydactyly type b syndrome coloboma of macula-brachydactyly type b syndrome coloboma of macula-brachydactyly type b syndrome, also known as sorbsy syndrome is a rare genetic disorder which is characterized by bilateral macular coloboma, nystagmus of the horizontal pendular type, visual impairment, and brachydactyly type b. additional findings include congenital anonychia, broad/duplication of the thumbs and big toes, syndactyly and camptodactyly. it is inherited in an autosomal dominant manner. it has been described in 9 members of a 4-generation british family. coloboma of macula-brachydactyly type b syndromeother namessorsby syndromeautosomal dominant patternspecialtymedical genetics, ophthalmologysymptomsmainly coloboma with type b brachydactylyusual onsetbirthdurationlifelongpreventionnonefrequencyraredeaths-