I also found this in Neonatology: Pathophysiology and Management of the
Newborn by Gordon Avery, Second Edition (1981---yes, another old book) page
1133:

In galactosemia, cataracts may appear as early as 7 days after
birth...Cataracts of a similar type may occur within 5 months of birth in
galactokinase deficiency....Systemic abnormalities are present in
[galactosemia] but---with the possible exception of mental retardation---not
in galactokinase deficiency.  Prompt diagnosis is of the utmost importance,
because in both disorders early dietary restriction of galactose (the major
source of which is the lactose in milk) can prevent cataracts from developing
and can also cause regression of established cataracts.

So this author seems to think that mental retardation is a possibility---my
other reference did not.  I've sent this to Tammy Bretscher.

Surely, someone out there has up-to-date references!  Please share them with
Tammy Bretscher ([log in to unmask]) and the rest of us!

Rita