Enzyme replacement therapy--an experiment of nature in a chimeric mannosidosis calf.

Enzyme replacement therapy was studied in a chimeric mannosidosis calf which had received a natural transplacental transplant of normal lymphocytes from its co-twin. There was considerable reduction in the pathology of certain organs and in the amount of storage oligosaccharides, but the clinical course of this neurologic disease was not significantly altered. It was postulated that if this disease had been purely visceral the transplant would have been relatively effective.