osteopetrosis autosomal recessive type 1

osteopetrosis autosomal recessive type 1

A severe autosomal recessive form (OMIM:259700) of osteopetrosis—a rare disease characterised by dense bone, due to defective resorption of immature bone—which is characterised by early (in utero, infancy or childhood) onset, macrocephaly, hepatosplenomegaly, progressive deafness and blindness (both attributed to pressure on nerves), and severe anaemia (attributed to marrow replacement).

Molecular pathology
Defects in TCIRG1 on chromosome 11q13.2, which encodes an osteoclast-specific H+-ATPase proton pump and multipass membrane protein, cause OPTB1.