Biallelic MITF mutations were also shown to cause the rare syndrome, COMMAD (coloboma, osteopetrosis, microphthalmia, macrocephaly, albinism—oculocutaneous type, and deafness) in two unrelated children whose heterozygous parents were affected with classic WS2A26, while children in another family had a WS4-like phenotype but with more severe depigmentation of hair and skin while their parents were mildly affected27. This evidence concerns the gene MITF and osteopetrosis.