Introduction

4H Syndrome is an autosomal recessive RNA-III-polymerase related leukodystrophy consisting of a triad of hypomyelination, hypodontia and hypogonadotroppic hypogonadism. We present a 5½-year-old girl who developed postinfectious cerebellar ataxia but was subsequently diagnosed to have 4H syndrome.

Case Summary

Few days following a varicella infection at 3½ years, the girl developed difficulty and swaying while standing and walking, tremors and unclear speech. There was mild improvement in her symptoms over next 6 months, though swaying while walking and tremors of hands persisted for next 2 years, when she presented to our hospital.

She is second child of a non-consanguineous marriage without similar family history. Her birth was uneventful. Development was normal till 3½ years, after which a delay in motor milestones was noted. Dentition had been delayed and disordered. On examination she had short stature, misshapen teeth and upper incisors had not yet erupted(Fig 1). Tone and reflexes were normal. Gait was ataxic with positive hemispheric cerebellar signs, and intention tremors but no nystagmus. MRI Brain revealed severe hypomyelination. She had high myopia, normal fundus, bilateral small ovaries and normal metabolic investigations. Diagnosis of 4H syndrome was confirmed by whole exome sequencing which revealed a previously reported homozygous mutation in POLR1C gene.

Conclusion

It is imperative to recognize non-neurologic clues like dental abnormalities, short stature and hypogonadism in leukoencepahlopathies to reach a correct diagnosis.