Osteopetrose - renale tubuläre Azidose
Osteopetrosis with renal tubular acidosis is a rare disorder characterized by osteopetrosis (see this term), renal tubular acidosis (RTA), and neurological disorders related to cerebral calcifications.
Prevalence of this disorder is not known. Fewer than 100 cases have been reported to date. Many reports involved families of North African and Middle Eastern descent, but cases have been documented worldwide.
Patients present a triad of mild osteopetrosis, mixed proximal and distal RTA, and intracerebral calcifications. Other clinical manifestations include fractures, growth failure and short stature, developmental delay, intellectual deficit, dental malocclusions/malalignment, cranial nerve compression and hearing impairment.
Osteopetrosis with renal tubular acidosis is caused by mutations in the CA2 gene (8q22) encoding carbonic anhydrase II.
Diagnosis is based on radiological findings in the presence of acidosis and intracerebral calcifications, and can be confirmed by molecular genetic testing.
Antenatal diagnosis is possible if the mutation(s) causing the condition in the family are known.
Transmission is autosomal recessive.
Treatment is symptomatic. Referral to a renal physician to manage the acidosis is recommended.
Severity is variable but the disorder has a milder course than in patients with classic osteopetrosis.
Quelle: Orphanet: an online rare disease and orphan drug data base. Copyright, INSERM 1997. Available on http://www.orpha.net. Accessed 17.01.2015