Objective To explore the clinical characteristics and molecular diagnosis of 4H syndrome.Methods The clinical data of 1 patient with 4H syndrome diagnosed by gene was retrospectively analyzed , and the clinical characteristics were analyzed combined with the literature .Results This child patient was male , 6 years and 8 months old, with hands shake for 1 years, mental and movement development backwardness , walking instability, teething delay .Ophthalmic examination showed myopia and optic atrophy .Brain MRI suggested a wide range of cerebral white matter lesions on both sides of the cerebral hemisphere .Gene examination showed POLR3A compound heterozygous mutation (c.1781T>G,c.2693delT).He was diagnosed as 4H syndrome.Conclusions The early manifestations of 4H syndrome are mental and movement development backwardness and teething delay .The main clinical features of 4H syndrome are leukodystrophy, myopia and ataxia.The genetic characteristics are POLR3A or POLR3B mutation.