Herein we report comparative functional studies on wild-type and mutant forms of recombinant human galactose-1-phosphate uridylyltransferase (GALT), seeking a molecular basis for the phenotypes assigned to classical galactosemia patients bearing the respective mutations. GALT plays a key role in galactose metabolism. Mutations in the GALT gene resulting in GALT deficiency set the basis for classical galactosemia, an autosomal recessive disorder. To date, more than 200 mutations have been described, the majority being missense. Novel mutations were identified in the Portuguese galactosemic population (e.g. G175D and P185S), which will be studied in parallel with other known mutations (R148Q, Q188R and S135L). To characterize the wild-type and mutant forms, GALT wild-type cDNA was cloned into pET24b(+), bearing an N-terminal 6xHis-tag, the mutations generated by site directed mutagenesis, and expressed in E. coli BL21(DE3) Rosetta cells, in LB medium supplemented with iron and zinc. After purification by affinity-chromatography, comparative functional studies were employed to evaluate the cofactor loading, oligomeric profiles, conformational stability and enzymatic activity of wild-type vs. mutant GALT. The results provided biochemical information confirming that the selected mutations are disease-causing, and contributed for the understanding of how the mutational spectrum in galactosemic patients modulates GALT functional properties. Background: Galactokinase deficiency (GALK) is a rare autosomalrecessive disease with an estimated incidence 1:150,000 to 1:1,000,000. Cataract formation due to accumulation of galactitol may already occur in early childhood. This can be prevented, reversed or ameliorated by early diagnosis and therapy with a galactose restricted diet. Methods: From 2000 to 2010 the Screening-Laboratory Hannover analyzed 2 million dried blood spot samples from neonates. Enzymatic activities of galactose-1-phosphate uridyltransferase (GALT) and galactose plus galactose-1-phosphate were quantified. Indirectly screening for GALK was accompanied; in cases with elevated galactose plus galactose-1-phosphate and normal GALT activity, GALK activity was measured in erythrocytes to confirm GALK deficiency. Results: In 9/11 cases with elevated galactose levels and normal GALT activity the diagnosis of GALK was confirmed. In two cases screening results were false positive. 3/9 children developed cataracts. Two children were treated with lentectomy. Under a galactose-restricted diet existing cataracts were stable or reversed; concentrations of galactose normalized. Galactokinase activities and cataract formation did not correlate. Conclusion: For galactokinase deficiency a therapy with galactose restricted diet is available and useful to ameliorate ophthalmological complications. Measurement of elevated galactose levels as well as normal GALT activity in newborn screening may be helpful to detect galactokinase deficiency early Background: Transaldolase (TALDO) deficiency is a rare inborn error of pentose phosphate pathway. So far 14 patients from 8 families were described. In the majority of these cases clinical course of the disease was severe with neonatal presentation and early death. In 2009 we described two transaldolase deficient brothers (6 and 4 years of age) with relatively mild phenotype. Patients: Three years of follow up revealed in the older brother (currently 8 years old) advanced liver (nodular) cirrhosis, hyperbilirubinemia, persisted moderate anaemia and thrombocytopenia, clotting disturbances, splenomegaly, low body mass. Since the age of 7 the boy developed tubulopathy, proteinuria and progressing renal damage, mild pulmonary fibrosis and cardiomegaly. His intellectual development and social functioning are adequate to the calendar age. He has persisted tendency to generalized edema, and ascites requiring diuretics administration. His younger brother (6 years old) presents less advanced liver cirrhosis, as well as anaemia, thrombocytopenia, clotting disturbances, tubulopathy, proteinuria and osteopenia. Conclusions: TALDO deficiency is mostly pronounced in liver but taking into account the severe renal, pulmonary and cardiac involvement, TALDO deficiency should be considered as severe multisystemic disease. Hereditary fructose intolerance (HFI) is an autosomal recessive disease caused by mutations in the ALDOB gene encoding aldolase B enzyme. If undiagnosed, the persistent ingestion of fructose can lead to severe liver and kidney damage and death. Molecular genetic analysis are essential and useful diagnostic tool for HFI because of less invasive methods. Recently, promoter mutations in ALDOB gene were identified in patients with HFI beside over 50 different type of known mutations. In this study, mutation screening of 2-9 exons and promoter region (untranslated exon 1) in ALDOB gene was carried out in 13 Turkish patients with HFI by using direct sequence analysis. Six different type of mutations in ALDOB gene (one splice site, three missense and two deletion) were detected. In this new cohort with HFI, ALDOB gene harbored for three novel mutations including IVS2-3deltagG, c.71delTTGCins11GAATCTCTGGG, IVS1+ 1 G>A and three known mutation, p.A175D and p.C135R in coding region and g. -132 G>A mutation in promoter region of the ALDOB gene. Background/Objectives: Lactose intolerance is the inability to metabolize lactose, because of the lack of enzyme lactase in the digestive system. There are known three major types of lactose intolerance. We report a patient with adult type of hypolactasia who was picked up by selective screening for galactosemia. Case report: 2-month-old boy with recurrent complaints of restlessness and meterorism. Urinary Benedict's test was positive and urinary monoand disaccharide analysis revealed the elevation of galactose. Repeated analysis showed even larger excretion of galactose and also galactitol. Lactose-free diet showed positive impact. All galactosemia subtypes were ruled out by enzymatic analysis, but hypolactasia was confirmed on molecular level. He is homozygous for c.-13910 C>T polymorphism in MCMG gene, which regulates lactase gene transcription. Methods: Urinary galactose/galactitol content was evaluated by HPLC with refractive index/ultraviolet-visible spectrophotometrical detectors. Results: concentration of glucose in urine was 0.08 mmol/l (ref<0.8), galactose 334 mmol/mol cr (ref<377); 1-month later urinary glucose 1 mmol/l (ref<0.8), galactose 782 mmol/mol cr, galactitol 597 mmol/mol cr (ref<30); sugar derivatives in organic acid GC/MS analysis. Lactose contents in urine were respectively 44.3 mmol/mol cr and 20.3 mmol/mol cr. Conclusion: Urinary galactose analysis might be a valuable tool for picking up infantile hypolactasia cases. Patients with Pompe disease (Glycogen storage disease (GSD) type II) have been shown to excrete increased amounts of glucose tetrasaccharide (Glc4) in urine, thought to be derived from the action of serum amylase on glycogen accumulated as a result of lysosomal acid alpha glucosidase deficiency. We have developed a simple, rapid and reproducible method for the analysis of Glc4 by HPLC-ECD, by adaptation of an established method for urine and faecal sugars analysis. Using this method, we were able to demonstrate elevated urinary Glc4 concentrations in all Pompe patients studied (n=11), with all control patients having concentrations below the limit of detection (5 μmol/mmol creatinine) (n= 21); and importantly, we were able to show a distinction in Glc4 excretion between Pompe patients and an individual harbouring a pseudo-Pompe mutation. A clear decrease in Glc4 excretion was observed following commencement of enzyme replacement therapy (ERT) in 3 Pompe patients studied.