Carbonic anhydrase II deficiency syndrome: A report of 18 new Saudi Arabian cases

Abstract

To describe the clinical, radiological and biochemical features of 18 new Saudi Arabian children with the carbonic anhydrase II deficiency syndrome, who have been in follow up at Al-Rass General Hospital in the period from September 2004 to September 2008. The medical records of these children were reviewed. The diagnosis was based on the typical clinical, radiological and biochemical evidence of the disease. These patients had characteristic clinical features, which include typical facial appearance and growth and psychomotor retardation. All patients had renal tubular acidosis (the majority have distal renal tubular acidosis) and metaphyseal osteopetrosis. Intracerebral calcifications were reported in 9 out of the 15 children in whom cranial tomography scan of the brain was performed. Half had nystagmus, about half had squint, another half had visual impairment and two patients had optic atrophy and total blindness. Two patients had hepatosplenomegaly with anemia and thrombocytopenia due to bone marrow involvement. Four patients had spastic quadriplegia and three patients had pectus carinatum. The median age of diagnosis was significantly lower than that reported, and two of the patients reported in this study represent the first two cases to be diagnosed at birth. Their intrauterine growth was normal, however radiological evidence of osteopetrosis were reported at birth, but renal acidosis developed at around 2 weeks of age. The syndrome of carbonic anhydrase II deficiency is prevalent in this region of Saudi Arabia. The disease has serious complications and early diagnosis is important. This series included the first two cases that were diagnosed at birth and also showed that central nervous system complications are common presentation of this syndrome.

Keywords

Osteopetrosis - renal tubular acidosis - intracranial calcification - carbonic anhydrase II deficiency