Epimerase-deficiency galactosemia is not a binary condition.
Openo KK, Schulz JM, Vargas CA, Orton CS, Epstein MP, Schnur RE, Scaglia F, Berry GT, Gottesman GS, Ficicioglu C, et al.
Am J Hum Genet. 2006 Jan; 78(1):89-102. Epub 2005 Nov 14.
[Am J Hum Genet. 2006]