I posted this to Tammy Bretscher ([log in to unmask]):

This is from Schaffer's Diseases of the Newborn, 5th edition (1984) page 534:

Galactose may appear in blood and urine as a result of deficient activity of
galctokinase or UDPG-4-epimerase.  Galactokinase deficiency has been
identified in the newborn as well as in older children.  In contrast to
galactosemia, this condition is not associated with an accumulation of
galactose-1-phosphate.  In the untreated state, cataracts will develop during
infancy or early childhood, but, unlike galactosemia, gactokinase deficiency
manifests no neonatal symptoms, and other complications such as liver disease
and mental retardation do not occur.  The diagnosis is suspected upon
discovery of large amounts of galactose in the blood and urine and confirmed
by demonstration of markedly reduced or absent galactokinase activity in
erythrocytes.  The treatment is identical with that for galactosemia in that
milk and milk products are excluded from the diet.  Neonatal screening in
which an assay for galactose is performed should detect galactokinase
deficiency as well as galactosemia.  It is important to identify and treat
this disorder in the neonatal period in order to prevent the formation of
cataracts.

UDPGalactose-4-epimerase (epimerase) deficiency has been described in only a
few families.  The affected infants or older individuals accumulate a small
amount of galactose in blood and a much larger amount of
galactose-1-phosphate in erythrocytes.  No signs of disease have been noted,
suggesting that this may be a benign disorder.  The diagnosisis confirmed by
the demonstration of reduced epimerase activity in erythrocytes.

<<Is a deficiency in galactokinase also considered galactosemia, or is
that term reserved for deficiency of galactose-1-phosphate uridyl
transferrase?>>
Galactosemia and galactokinase deficiency are two separate entities.

<<Are there degrees of disease, or are these deficiencies all-or-nothing?>>
As far as I know, all-or-nothing.

<<How common are false positives for any of these tests?>>
No idea.  But I would ask if testing is being done to differentiate
galactokinase deficiency from UDPC-4-epimerase deficiency---the latter seems
to be a benign condition, though this IS an older book...

<<How much damage would continuing to nurse for a week cause if there
is a deficiency in galactokinase, and what kind of damage could be
expected?>>
Cataracts, but I don't know how quickly they would develop.

<<Lawrence and Auerbach & Riordan say "the baby will soon develop
symptoms."  How soon is soon?  Days?  Weeks?  What kind of symptoms?>>
No idea how soon, but cataracts.

Can anyone add anything to this information, specifically how quickly
cataracts would develop in an untreated (breastfed) infant?  Also, the
reference I've quoted is thirteen years old.  Does anyone have access to a
text that is more up-to-date?  Any assistance you can render would be
appreciated.  Please e-mail Tammy directly ([log in to unmask]) as she is not
on Lactnet.  I'd like to see any replies as well ([log in to unmask])---you
can e-mail me directly, or post to Lactnet.

Rita