Manganese is a cofactor of enzymes involved in maintaining cellular homeostasis, whose exogenous intoxication causes only neurotoxicity, while inherited variant causes cirrhosis and polycythemia in addition.  We present two affected siblings born of non consanguineous parentage underlining the importance of early suspicion and detection before this treatable disorder causes irreversible damage.  

CASE 1

The pro-band was a 12 year old boy with normal birth history and global developmental delay, who presented with dysarthria, hypophonia, generalised dystonia and a typical “cock walk” type of gait.  His routine investigations showed polycythemia and normal liver parameters.  MRI Brain showed symmetric T1 hyperintensities in globus pallidus, pontine central segmental tract sparing ventral pons (“horseshoe moustache sign”) and dentate nucleus.  His serum Mn level was 119 ugm/L (Ref:03.-1.04 ugm/L).  Genetic study showed homozygous mutation in first exon of solute carrier family 30 member 10 (SLC30A10) gene(c.134T>C) and genetic segregation analysis of both parents showed heterozygous mutation in same gene, confirming the diagnosis.

CASE 2

The younger sibling of the pro-band was 6 year old boy and had similar clinical presentation, but was mild and intermittent, who in addition had coarse echo texture of liver on screening ultrasound abdomen.  His serum manganese level was also elevated and genetic analysis showed the same gene mutation as his elder brother.  Both the siblings were treated with disodium calcium edetate and oral iron supplementation, with which they had moderate benefit of symptoms and are being kept under followup.  

Hypermanganesemia with dystonia type 1 syndrome must be suspected in a child with progressive dysarthria without dysphagia, generalised dystonia and cock-walk type of gait.  This disorder being a treatable condition must be always borne higher in clinical differentials.