ABSTRACT
Hepatic dysfunction is another feature of Pearson syndrome. Similarities and differences between this syndrome and Schwachman syndrome, in which exocrine pancreatic insufficiency is associated with hematologic disease, have been considered. In Schwachman syndrome, the marrow abnormality leads to leukopenia, and the histology is of pancreatic fatty replacement. There is also bony metaphyseal dysplasia. In Pearson syndrome, vacuolation of marrow cells is distinctive; there has also been autopsy evidence of splenic atrophy. A clinically normal mother could also have more than offspring with this syndrome, especially if there were germ-line mosaicism. Similar clinical abnormalities with different deletions of mtDNA may be consistent with the fact that even small deletions include several tRNA genes and the transcript is not translated. The size and percentage of the deletions do not predict the clinical course or severity of disease.
