Acute necrotizing encephalopathy (ANE) is a rapidly progressive encephalopathy that can occur in otherwise healthy children after common viral infections such as influenza and parainfluenza. Most ANE is sporadic and nonrecurrent (isolated ANE). However, we identified a 7 Mb interval containing a susceptibility locus (ANE1) in a family segregating recurrent ANE as an incompletely penetrant, autosomal-dominant trait. We now report that all affected individuals and obligate carriers in this family are heterozygous for a missense mutation (c.1880C-->T, p.Thr585Met) in the gene encoding the nuclear pore protein Ran Binding Protein 2 (RANBP2). To determine whether this mutation is the susceptibility allele, we screened controls and other patients with ANE who are unrelated to the index family. Patients from 9 of 15 additional kindreds with familial or recurrent ANE had the identical mutation. It arose de novo in two families and independently in several other families. Two other patients with familial ANE had different RANBP2 missense mutations that altered conserved residues. None of the three RANBP2 missense mutations were found in 19 patients with isolated ANE or in unaffected controls. We conclude that missense mutations in RANBP2 are susceptibility alleles for familial and recurrent cases of ANE.

Acute necrotizing encephalopathy of childhood is a novel type of parainfectious encephalopathy with a racial and geographic predilection, rarely reported from other than East Asian areas. The objective was to describe the clinical, imaging, and other laboratory findings of non-Asian patients with acute necrotizing encephalopathy. Data were collected from three patients diagnosed in Athens over a 4-year period plus 16 cases reported from other European and North American countries. One of the Greek children died, and the other two had a normal outcome. A neuropathologic examination in the fatal case showed edematous necrosis without inflammatory, reactive, or proliferative changes. Data from Greek and other non-Asian patients support the homogeneity of the disease worldwide.

This study aimed to investigate whether carbamazepine, sodium valproate or phenobarbital as monotherapy in ambulatory epileptic children with adequate sun exposure have some effect on their bone metabolism based on the determination of total serum alkaline phosphatase (AP) levels and its bone isoenzyme activity. Blood samples were obtained from 118 epileptic children (37 on carbamazepine, 47 on sodium valproate and 34 on phenobarbital) and from corresponding healthy controls matched for age, gender and anthropometric parameters. AP and its liver, bone and intestinal isoenzyme levels, other common biochemical markers of bone and liver metabolism and drug levels were measured in the study participants. Patients on carbamazepine or phenobarbital had significantly elevated AP levels accompanied by increased bone and liver isoenzyme activity compared to controls. An increase of bone AP isoenzyme values, correlated with the duration of treatment ( r= 0.49, P= 0.002), was found in children on sodium valproate without, however, a concomitant significant elevation of total AP values. We conclude that children who receive antiepileptic drugs as monotherapy, even when residing in a Mediterranean country with adequate sunlight, may have their bone metabolism affected as indicated by the elevated levels of bone AP isoenzyme. This isoenzyme, but not total AP values, could therefore be used as a marker for the selection of patients who would be benefited by a thorough evaluation of their bone metabolism profile.