Familial cerebellar hypoplasia and pancytopenia without chromosomal breakages

Two siblings manifested a neuro-haematologic syndrome characterised by low birth weight, failure to thrive, chronic persistent tongue ulceration, seve re truncal ataxia and pancytopenia without either telangiectasia or chromos omal instability. One sibling died from sepsis and the cerebellum demonstra ted reduced cellularity of the molecular and granular layers with relative preservation of Purkinje cells and minimal gliosis, A surviving sibling has shown haematologic progression to a myelodysplastic disorder. There was no evidence of any chromosomal instability following exposure of fibroblasts and lymphocytes to irradiation, Monasomy-7 was not present in the surviving sibling. We suspect that these two patients represent another example of t he rare Hoyeraal-Hreidarsson syndrome and we are currently engaged in very close monitoring of the surviving sibling for evidence of any karyotypic ab normality.