The frequency of multiple sclerosis (MS) with clinical onset before 16 year
s 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 exacerb
ation 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: num
erous large lesions, typical for MS on T2 images were often seen in childre
n with mild or moderate residual neurological symptoms. All patients had re
lapsing/remitting MS course, mean EDSS was 2.24 +/- 0.26. Thirty-eight chil
dren (80%) had ON at least once, ten (21.3%) -twice or more times. In sever
al cases ON had subclinical course or might be missed and the damage of the
optic nerve with partial atrophy was found only after complex ophthalmolog
ical investigation including visual evoked potentials. Thus, the clinical c
ourse of MS and ON have some peculiarities in children and may be genetical
ly based. Analyses of allelic polymorphisms of HLA-DR and TNF loci on chrom
osome 6 was performed. Data from children with MS were compared with data f
rom their parents, healthy controls and other MS patients from the same eth
nic group. Children with MS had increased frequency of DR2(15) and TNF-all,
but not TNF-a9 as adult MS patients from the same ethnic group. The presen
ce of TNF-a7, rare in adult patients, could be proposed as a marker of earl
y MS onset.