Revised proposal for the prevention of low bone mass in patients with classic galactosemia

Decreased bone mass is frequently encountered in classic galactosemia, an inborn error of galactose metabolism. This decrease is most prominent in adults, but is already seen in prepubertal children with increased risk of osteoporosis and fractures later in life. Therefore, bone health in patients with classic galactosemia is increasingly monitored. Although the pathophysiological mechanism is still not fully understood, several factors could negatively affect bone metabolism in this disease. Patients are at risk of nutritional deficiencies due to the galactose-restricted diet. Primary ovarian insufficiency (POI) in female patients also contributes to decreased bone mass. Furthermore, patients with classic galactosemia might be less physically active due to motor or neurological impairments. A disease-specific intrinsic abnormality has been suggested as well. This revised proposal is an update of the 2007 recommendations. In this current approach, we advise comprehensive dietary evaluation, optimization of calcium intake if needed, monitoring and if necessary supplementation of vitamin D, hormonal status evaluation and hormone replacement therapy (HRT) consideration, as well as a regular exercise and assessment of skeletal deformities and clinically significant fractures. We propose bone mineral density (BMD) assessment by serial DXA scans of the lumbar spine, femoral neck, and total hip in adults and lumbar spine and total body less head (TBLH) in children.