Last modified: 2018-09-09
Abstract
Background : Neuroimaging doesn’t play a major role while evaluation of children with primary dystonia.Hereby we present a 3-year old boy with early-childhood onset dystonia with interesting neuroimaging, which clinched the diagnosis.
Method & Result : A 3-year-old boy, first born of a third-degree consanguineous parentage had presented with recurrent falls and toe walking from 2-years of age. Birth and perinatal events were uneventful. On examination, he had microcephaly (45 cm at -3 Z score, WHO), mild calf muscle hypertrophy, bilateral tendo-achilles contractures and when made to walk with support prominent foot dystonia was noted. An initial neuroimaging done revealed symmetrical T1-weighted hyper-intense signal changes in basal ganglia, midbrain, periaqueductal grey matter, superior colliculus, middle cerebellar peduncle and dentate nuclei.Blood investigations identified markedly elevated serum manganese levels 186 microgram/l (5- 15). NGS revealed a previously unreported homozygous single base pair insertion c.18_19insT in exon 1 of SLC30A10 gene that results in stop codon and premature truncation of protein at codon 7(p.Lys7Ter).
Discussion: Inherited hypermanganesemia are caused due to mutations in SLC30A10, SLC39A14 and SLC39A81.Homozygous mutations in SLC30A10 manifests in childhood(2-15 years) with four-limb dystonia(cock-walk gait), dysarthria, polycythemia, hepatic cirrhosis and characteristic neuroimaging as in index child.Chelation with EDTA and iron supplementation is beneficial.
Conclusion: Genetic hypermanganesmia with early childhood-onset dystonia can easily be identified based on characteristic neuroimaging and initiation of chelation is beneficial.