Blepharophimosis-intellectual disability syndrome, SBBYS type is characterised by the association of congenital hypothyroidism, facial dysmorphism (microcephaly, blepharophimosis, a bulbous nose, thin lip, low-set ears and micrognathia), postaxial polydactyly and severe intellectual deficit. Less than 20 cases have been reported so far. Cryptorchidism is present in affected males. Some patients also have cardiac anomalies (interventricular communication), hypotonia and growth delay. Autosomal recessive inheritance has been suggested.

Hard-palate submucous clefts are characterized by bony defects in the midline of the bony palate that are covered by the mucous membrane of the roof of the mouth. It may be possible to detect a submucous cleft hard palate upon palpation as a notch in the bony palate.