21-hydroxylase deficiency is one of the forms of adrenogenital syndrome.
One manifestation is electrolyte imbalance due to adrenal hormones being
deficient.  If properly controlled on replacement hormones, these kids do
fine.  The Ped may be concerned that breastmilk has a lower sodium load
than ABM, but the solution would be to better regulate the hormone levels
to keep from losing sodium in the urine, NOT to wean.

Becky Saenz, MD
Assistant Professor
University of MS Medical Center
Department of Family Medicine
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