| Disease ID | Source | Name | Description |
| 615085 | OMIM | Osteopetrosis, autosomal recessive 8 (OPTB8) | A rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. Osteopetrosis occurs in two forms: a severe autosomal recessive form occurring in utero, infancy, or childhood, and a benign autosomal dominant form occurring in adolescence or adulthood. Recessive osteopetrosis commonly manifests in early infancy with macrocephaly, feeding difficulties, evolving blindness and deafness, bone marrow failure, severe anemia, and hepatosplenomegaly. Deafness and blindness are generally thought to represent effects of pressure on nerves. OPTB8 is clinically characterized by dense bones with no distinction between outer and inner plates, due to extensive encroachment of cortical bone into the medullary space, increased head circumference, broad open fontanelle, frontal bossing, and hepatosplenomegaly. Osteoclasts number is low and their bone resorptive capacity is impaired. The disease is caused by variants affecting the gene represented in this entry. |