Introduction: Pontocerebellar hypoplasia an autosomal recessive neurodegeneration, causing important neurodevelopment delay. It affects less than 1 from 1000000 inhabitants. From the ten subtypes, that have been reported, type 1, results from a severe cerebellar underdevelopment, associated to a degeneration in the moto neuron of the spinal cord. Exosomes are affected, especially EXOSC3, EXOSC8, EXOSC9. These children have a significant hypotonia, visual dysfunction, dysphagia, respiratory failure and psychomotor retardation. Most of them, will die the first year of life. There are some exceptions, patients with minor affections.

Case Description: An infant, diagnosticated of severe gastroesophageal reflux, who started with a motor development delay and hypotonia. Even after having early stimulation and daily neurorehabilitation. He had a bad progress, characterize by inadequate gaining of weight, axial and peripheral hypotonia, generalized weakness, and neurodevelopment retardation. For that reason, some exams were preform: electromyography that suggest motor neuron disease. The first magnetic resonance was normal. Months later a new one was done, at his 18 months, which reflects a vermis hypoplasia and cortical atrophy. Finally, an EXON sequence c.395A>c (p.Asp132Ala), demonstrated EXONC3 homozygosis.

Discussion: Pontocerebellar hypoplasia is a neurodegenerative pathology, even though it is rare. As some subtypes have been reported, clinical manifestations are variable. Patients have a high risk of mortality. Neuroradiology and genetic exams are necessary for an accurate diagnosis.