Mondo Description X-linked neurodegenerative syndrome, Bertini type is characterised by generalised hypotonia, psychomotor deficit, congenital ataxia and recurrent bronchopulmonary infections. It has been described in seven males from three generations of a family. Five of them died during the first years of life and the remaining patients developed myoclonic encephalopathy and macular degeneration. The locus has been mapped to Xp22.33-pter.