Classical Galactosaemia and Bone Mineral Density - Abstract
Objective: Classic galactosaemia (CG), due to Galactose-1-phosphate uridylyltransferase (GALT), deficiency presents in neonates after exposure to galactose. On galactose restricted and lactose free diet, the mainstay of treatment of CG, initial symptoms recede but patients still experience long term complications including impaired bone health. Decreased bone mineral density (BMD), has been observed in pre-pubertal children increasing the risk of osteoporosis and fractures later in life. We present longitudinal and individual serial data on bone health in CG patients by retrospective analysis of clinical and biochemical data.
Patients and methods: A total of 47 CG patients between the ages of 10-18 years old from a single centre were included. Data on clinical presentation, comorbidities, mobility status, BMD, hormone replacement therapy (HRT), and fracture data was collected. In addition, biochemical results including: Vitamin D, calcium, galactose-1-phosphate, alkaline phosphatase and sex hormone levels were collected and analysed.
Results: There was significant difference (p=0.02), in BMD age matched Z-scores of female and male patients. There was modest improvement in BMD in female patients on hormone replacement therapy. Vitamin D insufficiency was observed and treated in 34% of the subjects. Calcium and ALP remained within normal range.
Conclusions: Patients in this study demonstrated low BMD median age matched Z-score (-1.7 SD). Impaired bone health is a common feature in children with CG. This occurs despite prompt initiation and good compliance to treatment. The aetiology of reduced BMD in galactosaemia has not been fully elucidated. Understanding the pathogenic mechanism will inform development of improved therapeutic strategies.