Osteopetrosis due to homozygous chloride channel ClCN7 mutation mimicking metabolic disease with haematological and neurological impairment.
We report on the fatal clinical course of a 3 year old male Turkish patient suffering from osteopetrosis caused by a homozygous mutation in the chloride channel gene ClCN7 with developing pancytopenia and severe neurological impairment. Hepatosplenomegaly due to extramedullary hematopoesis, severe transfusion-dependent anemia and growth failure initially suggested metabolic or oncologic disorder. Particular haematological parameters like tear drop cells basophilic punctation of the polymorphonuclear cells in the absence of haemolysis caused the diagnostic X-ray investigations of the skull and vertebral column. Raised serum creatinkinase-BB isoenzyme and genetic testing were in line with the diagnose of osteopetrosis at an age of 2(1/2) years.


CONCLUSIONS
Osteopetrosis is a rare but considerable differential diagnose for unclarified change in haematopoetic cell lines combined with severe neurological symptoms mimicking metabolic or haematological disease. Because of this rare disease a consensus protocol for diagnostics, treatment and follow up of patients suffering from osteopetrosis is recently worked out from the European Group of Blood and Marrow Transplantation (EBMT) and the European Society for Immundeficiencies (ESID) to build up a central registry for this disease (available by ansgar.schulz@uniklinik-ulm.de).
Furthner
D
D
Department of Paediatrics, Children's Hospital Linz, Linz, Austria. dieter.furthner@gespag.at
Biebl
A
A
Weinzettel
R
R
Schmitt
K
K
Lahr
G
G
Ebetsberger
G
G
Rittinger
O
O
Schulz
A S
AS
D000469:Alkaline Phosphatase / Q000097:blood; D002675:Child, Preschool; D018118:Chloride Channels / Q000235:genetics*; D002869:Chromosome Aberrations; D003062:Codon / Q000235:genetics; D052276:Creatine Kinase, BB Form / Q000097:blood; D004252:DNA Mutational Analysis; D003937:Diagnosis, Differential; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000235:genetics; D005091:Exons / Q000235:genetics; D017809:Fatal Outcome; D005808:Genes, Recessive / Q000235:genetics; D006411:Hematopoiesis, Extramedullary / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008297:Male; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000235:genetics*; D010022:Osteopetrosis / Q000000981:diagnostic imaging / Q000235:genetics*; D011859:Radiography; D012886:Skull / Q000000981:diagnostic imaging; D013131:Spine / Q000000981:diagnostic imaging
C097540:CLCN7 protein, human; D018118:Chloride Channels; D003062:Codon; D052276:Creatine Kinase, BB Form; D000469:Alkaline Phosphatase