We report three Chinese patients who demonstrated ataxia, oculomotor apraxia, choreoathetosis, myoclonus and telangiectasias of the eyes.

Sequence analysis of ATM revealed two known missense mutations c.8287C > T and c.9139C > T in the siblings. Intrafamilial clinical heterogeneity was observed in the siblings.

The other patient was compound heterozygote for ATM: c.8911C > T and c.7141_7151delAATGGAAAAAT, both of which were new and not found in 200 controls.

This study widens the spectrum of mutations and phenotypes in ataxia telangiectasia.