Response to milk in infancy: Most infants with DG who consume breast milk or formula containing milk
do not show symptoms; however, some infants with DG may show symptoms like jaundice, vomiting, or
diarrhea, after drinking milk. Infants who do show these symptoms typically recover quickly when
switched to a non-dairy diet, such as soy formula. To be clear, there are many reasons why an
infant with or without DG may show sensitivity to breast or cow’s milk, and the prevalence of milk
sensitivity, such as a milk protein allergy, is estimated at >1% in the general population, which is more
than 40 times the prevalence of DG.

Developmental outcomes later in childhood: While many healthcare providers have believed for years
that most children and adults with Duarte galactosemia (DG) do well, until recently no large study had
been reported testing whether DG is associated with an increased risk for specific developmental
difficulties. Here are the relevant studies published as of January 2019:

In this study of developmental outcomes among a small number of toddlers and very young children
with DG, the authors did not find evidence of significant developmental problems.

In both of these studies of older children with DG, the authors reported some evidence of possible
developmental problems. However, one of these studies was indirect (meaning they got their
information from records and not from testing the children) and both were small.

This study assessed 73 outcomes representing 5 developmental domains in 350 children, ages 6-12
years old; 206 of these children had DG and 144 did not. These authors found no significant differences
in prevalence of the outcomes tested between the children with DG and the children without DG in the
study. This study also did not find significant differences in outcomes tested between children with DG
who drank milk as babies, and children who drank low-galactose formula.

Ovarian outcomes: Premature ovarian insufficiency, a common experience among girls and women
with classic galactosemia, has been checked by hormone studies and does not appear to occur at high
prevalence among girls with DG. To read more about that study, see: