GALK1 and classic galactosemia: Females heterozygous for pathogenic variants in GALT and with other types of galactosemia, such as GALK1 deficiency, do not have chronically elevated levels of gal-1P, have a normal ovarian reserve, and do not undergo menopause at a premature age (Knauff et al. 2007, Badik et al. 2011, Rubio-Gozalbo et al. 2021).