IllnessOsteochondromas

NGS +

[Sanger]

In hereditary multiple osteochondromatoses, patients develop multiple benign osteochondromas whose number and location vary widely. These osteochondromas are not yet present in the newborn, but almost all affected individuals develop multiple exostoses by the age of 12 years. Osteochondromas grow at the end of the long bones, on the scapula, and the hip bones. Osteochondromas can interfere with normal bone growth, resulting in short stature and arms and legs that may vary in length and may be curved. Multiple osteochondromas can also lead to chronic pain, limited joint mobility due to pressure on nerves, blood vessels, the spinal cord and the tissues surrounding the osteochondromas. Osteochondromas are usually benign, but rarely sarcomas can develop (up to 5% lifetime risk). Skeletal studies suggest that a solitary osteochondroma as a benign bone tumor is found in 1-2% in the general population. The inheritance of multiple osteochondromas is autosomal dominant, and the penetrance for EXT1/2 mutations is approximately 96% in females and complete in males. The DNA diagnostic yield is up to 90%. Therefore, an inconspicuous molecular genetic result does not exclude the clinical diagnosis.

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1235/

• Alias: Hereditary multiple osteochondromas
• Allelic: Chondrosarcoma (EXT1)
• Allelic: Glioma, susceptibility to, somatic (IDH1)
• Allelic: LEOPARD syndrome 1 (PTPN11)
• Allelic: Noonan syndrome (PTPN11)
• Allelic: Seizures, scoliosis, macrocephaly syndrome (EXT2)
• Exostoses, multiple, type 1 (EXT1)
• Exostoses, multiple, type 2 (EXT2)
• Metachondromatosis (PTPN11)
• Metaphyseal chondromatosis + D-2-hydroxyglutaric aciduria/Spondyloenchondromatosis (IDH1)