title: Serum markers of bone turnover in children and adolescents with classic galactosemia.
abstract: OBJECTIVE
  Classic galactosemia is an inherited metabolic disease resulting from galactose-1-phosphate uridyltransferase (GALT) deficiency. Dietary lactose exclusion reverses many clinical manifestations of acute phase of the disease. Unfortunately most of the patients, despite dietary treatment, develop long-term complications among them disturbances of bone mineralization resulting in decrease of bone mineral density (BMD). The aim of our study was to assess bone formation and resorption processes with bone turnover markers in children and adolescents with galactosemia.
  
  
  METHODS
  We studied 62 galactosemic children (mean age+/-SD 5.9+/-2.7 years) and adolescents (mean age+/-SD 15.6+/-2,4 years). The clinical diagnosis had been confirmed by the absence of GALT activity in erythrocytes. All patients were diagnosed in the neonatal period and had good dietary control. Healthy children (n=70) were the reference group. Serum osteocalcin (OC), bone alkaline phosphatase (BALP), collagen type I crosslinked C-telopeptide (CTX-I), 25(OH)D metabolite of vitamin D were determined by ELISA assays.
  
  
  RESULTS
  We observed similar mean values of bone formation markers in children with galactosemia as compared to the age-matched controls. The level of bone resorption marker CTX-I in these patients was lower by about 20% (p<0.001) than in healthy children. On the contrary we obtained slightly higher values of CTX-I in adolescents with galactosemia in comparison to the age-matched controls. In these patients the values of OC and BALP were significantly higher than in healthy adolescents (111.8+/-52.1 microg/L versus 82.3+/-43.0 microg/L, p<0.02; and 95.4+/-45.7 U/L versus 72.6+/-40.6 U/L, p<0.05 respectively).
  
  
  CONCLUSIONS
  Our results suggest that bone turnover in galactosemic patients elevates from childhood to adolescence, whereas in healthy individuals there is a decline during aging. Further studies on adults with galactosemia are necessary to assess bone status in these patients.
authors.affiliation: Department of Newborn Screening, Institute of Mother and Child, Warsaw, Poland. biochem@imid.med.pl
authors.forename: J
authors.initials: J
authors.lastname: Gajewska
authors.forename: J
authors.initials: J
authors.lastname: Ambroszkiewicz
authors.forename: B
authors.initials: B
authors.lastname: Radomyska
authors.forename: M
authors.initials: M
authors.lastname: Chełchowska
authors.forename: M
authors.initials: M
authors.lastname: Ołtarzewski
authors.forename: T
authors.initials: T
authors.lastname: Laskowska-Klita
authors.forename: A
authors.initials: A
authors.lastname: Milanowski
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism*; D002113:Calcification, Physiologic; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D024042:Collagen Type I / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005693:Galactosemias / Q000097:blood* / Q000473:pathology; D006801:Humans; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010012:Osteogenesis; D010455:Peptides / Q000097:blood; D014807:Vitamin D / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D014807:Vitamin D; D000469:Alkaline Phosphatase