[Hypomyelination with atrophy of the basal ganglia and cerebellum. Contribution of two new cases to a recently reported entity].

INTRODUCTION

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare condition that has only recently been reported. Here we present two new cases belonging to the same family.

CASE REPORTS: Case 1: 17-month-old boy with severe underdevelopment in all areas, absence of language and eye contact. The examination revealed microcephaly with spastic tetraparesis. A magnetic resonance imaging scan showed predominantly vermian atrophy of the cerebellum with loss of volume of both nuclei of the putamen and the head of the caudate, and a pattern of hypomyelination of the white matter. Electromyography recording highlighted the presence of a predominantly motor pattern of chronic polyneuropathy. Homovallinic acid and 5-hydroxyindoleacetic acid values were lower than usual. Treatment with levodopa/carbidopa was not effective. Case 2: 11-month-old girl, the sister of the boy in the previous case. The patient presented severe underdevelopment in all areas and microcephaly with spastic tetraparesis was detected in the clinical examination. Magnetic resonance imaging of the head showed findings that could be superimposed upon those of the brother, with hypomyelination, cerebellar atrophy and involvement of the putamen and both caudates; electromyography findings were consistent with motor polyneuropathy of a demyelinating nature. Homovallinic acid and 5-hydroxyindoleacetic acid values in cerebrospinal fluid were lower than usual. Treatment with levodopa/carbidopa was ineffective.

CONCLUSIONS

These two new cases help characterise this condition better and reinforce the hypothesis of the genetic origin of the syndrome, given that the two cases occurred in the same family.