[Pontocerebellar hypoplasia type 1: a case report]

Pontocerebellar hypoplasias constitute a group of hereditary neurodegenerative disorders of uncertain aetiopathogenesis. They have been reported as being associated with deficiencies of complexes in the mitochondrial respiratory chain (MRC) and with congenital disorders of glycosylation. On the basis of clinical and neuropathological criteria, two phenotypes can be distinguished in this condition. Pontocerebellar hypoplasia type 1 is characterised by hypoplasia of the pons and the cerebellum associated with the degeneration of the motor neurons in the anterior horn of the spinal cord.

A 4-year-old female with symptoms of severe psychomotor retardation associated with microcephaly, important generalised hypotonia, muscle hypotrophy, contractions in the four limbs, absence of stretch reflex and epilepsy with onset in the neonatal period. Magnetic resonance imaging of the brain revealed pontocerebellar hypoplasia. An electroneuromyography showed a trace that was compatible with axonal neuropathy and a biopsy of the deltoid muscle revealed the existence of neurogenic muscular atrophy. In the MRC study conducted in muscle homogenate and in skin fibroblasts, complex IV values were found to be at the lower limits of what could be considered to be normal levels. Results of the genetic study for spinal muscular atrophy were negative.

The case reported here could be included as a case of pontocerebellar hypoplasia type 1. MRC studies can be of interest in cases of pontocerebellar hypoplasia in order to explain the role it plays in this disorder.