Association and linkage of juvenile MS with HLA-DR2(15) in Russians.

The aim of this study was to determine the role of the HLA-DRB1 gene [6p21] in susceptibility to juvenile MS (JMS) (age at onset < or =15 years) of children of Russian descent. Association of DR2(15) with JMS has been found by the comparison of patients with JMS with both unrelated and affected family-based healthy controls. The linkage of DR2(15) with JMS was shown by transmission disequilibrium test. There were no significant differences in the frequencies of DRB1 alleles and genotypes between 56 patients with JMS and 234 patients with MS with age at onset > or =16 years.

Clinico-immunogenetic characteristics of multiple sclerosis with optic neuritis in children.

The frequency of multiple sclerosis (MS) with clinical onset before 16 years of age in different regions of Russia fluctuates from 2 to 10% of all MS patients. One of the most frequent signs of MS manifestation and/or exacerbation at this age is optic neuritis (ON). Forty-seven children with MS were observed in Moscow. Diagnosis of MS in every case was clinically definite and proved by serial MRI. Clinico-tomographic dissociation was noticed: numerous large lesions, typical for MS on T2 images were often seen in children with mild or moderate residual neurological symptoms. All patients had relapsing/remitting MS course, mean EDSS was 2.24+/-0.26. Thirty-eight children (80%) had ON at least once, ten (21.3%) - twice or more times. In several cases ON had subclinical course or might be missed and the damage of the optic nerve with partial atrophy was found only after complex ophthalmological investigation including visual evoked potentials. Thus, the clinical course of MS and ON have some peculiarities in children and may be genetically based. Analyses of allelic polymorphisms of HLA-DR and TNF loci on chromosome 6 was performed. Data from children with MS were compared with data from their parents, healthy controls and other MS patients from the same ethnic group. Children with MS had increased frequency of DR2(15) and TNF-a11, but not TNF-a9 as adult MS patients from the same ethnic group. The presence of TNF-a7, rare in adult patients, could be proposed as a marker of early MS onset.