Autosomal Recessive Osteopetrosis 1

**Semantic type:** Congenital Abnormality

**Definition:** A sub-type of autosomal recessive osteopetrosis caused by mutation(s) in the TCIRG1 gene on chromosome 11q13, encoding the osteoclast-specific (alpha 3) subunit of the vacuolar proton pump. It is characterized by macrocephaly, frontal bossing, nystagmus, optic atrophy, blindness, deafness, and facial palsy.

**Synonyms:** - ARO1 - Autosomal Recessive Albers-Schonberg Disease - Autosomal Recessive Marble Bones - Autosomal Recessive Osteopetrosis Type 1 - Infantile Malignant Osteopetrosis 1 - OPTB1