Galactosemia is an autosomal recessive disorder caused by deficient or absent activities of one of the three enzymes involved in the galactose metabolic pathway. The predominant form is classic type galactosemia cause...Galactosemia is an autosomal recessive disorder caused by deficient or absent activities of one of the three enzymes involved in the galactose metabolic pathway. The predominant form is classic type galactosemia caused by severe reduction or absence of the galactose- 1-phosphate uridyl transferase (GALT) enzyme. Coexistence of extrahepatic biliary atresia (EHBA) with Duarte 1 and 2 variants of galactosemia has not been described earlier. Here we report a case of EHBA with concordant Duarte 1 and 2 variants of galactosemia in an infant with cholestasis. Genetic analysis of the index patient for galactosemia revealed presence of Duarte 1/Duarte 2 variants of galactosemia with genotype N314D-L218L/N314D-G1105C-GI391A- G1323A-5’UTR-119delGTCA. Clinical evaluation of the patient showed the presence of EHBA. Henceforth, it may be hypothesized that EHBA may have a genetic basis with simultaneous involvement of the GALT gene.展开更多
We describe the GALT-Prot database and its related web-based application that have been developed to collect information about the structural and functional effects of mutations on the human enzyme galactose-l-phospha...We describe the GALT-Prot database and its related web-based application that have been developed to collect information about the structural and functional effects of mutations on the human enzyme galactose-l-phosphate uridyltransferase （GALT） involved in the genetic disease named galactosemia type I. Besides a list of missense mutations at gene and protein sequence levels, GALT-Prot reports the analysis results of mutant GALT structures. In addition to the structural information about the wild-type enzyme, the database also includes structures of over 100 single point mutants simulated by means of a computational procedure, and the analysis to each mutant was made with several bioinformatics programs in order to investigate the effect of the mutations. The web-based interface allows querying of the database, and several links are also provided in order to guarantee a high integration with other resources already present on the web. Moreover, the architecture of the database and the web application is flexible and can be easily adapted to store data related to other proteins with point mutations. GALT-Prot is freely available at http：//bioinformatica.isa.cnr.it/GALT/.展开更多
Background:Galactosemia due to complete or near-complete galactose-l-phosphate uridyltransferase(GALT)deficiency was the first disorder added to the pioneering newborn screening panel besides phenylketonuria.In the la...Background:Galactosemia due to complete or near-complete galactose-l-phosphate uridyltransferase(GALT)deficiency was the first disorder added to the pioneering newborn screening panel besides phenylketonuria.In the last 50 years,many criticisms have been focused on the opportunity of its inclusion.Consequently,long-term single center experiences with this issue are generally lacking.Methods:We reviewed the outcome of newborn screening for hypergalactosemia performed at our department since 1982 and the correspondent long-term clinical outcome.Results:Among 1123909 newborns screened for hypergalactosemia,33 showed abnormal results confirmed at second tier test.Thirteen patients were affected with classic galactosemia,8 partial GALT deficiency,3 severe galactokinase deficiency,7 transient galactosemia,one congenital porto-systemic shunt,and one glucose transporter 2 deficiency.Acute neonatal liver failure in the late first week of life(5.8±1.1 days)unavoidably complicated the clinical course of classic galactosemia,unless in three second-born siblings treated on the basis of presumptive diagnosis immediately after newborn screening sample collection on day 3.Despite early treatment and longterm steadily normal peripheral blood galactose,77%of patients with severe GALT deficiency present mild to severe intellectual disabilities.All patients with partial GALT deficiency showed normal intellectual development on a regular diet,as well as patients with galactokinase deficiency under treatment.Conclusions:Availability of screening results within the fifth day after birth would allow the prevention of acute decompensation in classic galactosemia.A systematic diagnostic work-up in all positive newborns is essential to unravel the etiology of hypergalactosemia.展开更多
Most newborn screening laboratories use CE-marked or FDA-approved test-kits, like in routine clinical chemistry. National regulations require only minimal evaluation from the customer, if the test-kits are used as spe...Most newborn screening laboratories use CE-marked or FDA-approved test-kits, like in routine clinical chemistry. National regulations require only minimal evaluation from the customer, if the test-kits are used as specified by the manufacturer. The microtiter-based kit-concept is often based on the perception, that the laboratory always processes whole microtiter plates. However, in the daily routine, this is rather a rare exception, which leads to much higher costs per newborn, compared to the costs per assay in the test-kits. In addition the amount of wasted resources is quite high. Performance of the Neonatal Total Galactose kit from Perkin Elmer was tested. We have determined specificity, limit of detection (LOD), limit of quantitation (LOQ), intra and inter assay variation, recovery, stability of measuring signal and reagents. Results were also compared with the Astoria Pacific Spot Check System. In addition, we had (by chance) the opportunity to test 2 kits, which were already expired for more than 3 years. LOD was 165 - 306 μmol/L and LOQ 475 - 703 μmol/L, depending on the definition of LOD/LOQ. Mean recovery was 112.8%, intra assay CVs were 11.3, 7.3, 4.0, and 3.0, and inter assay CVs 28.7, 15.9, 7.8, and 9.3, at 220, 590, 1200, and 2060 μmol/L respectively. Reconstituted and mixed reagents must be used within some hours, and were unstable even if stored at -20℃. However, if the reconstituted galactose substrate reagent and galactose oxidase reagent were only mixed according to the daily requirements, and the rest stored separately at -20℃, they were stable for at least 12 days. The performance of the expired test-kits did not differ from the others. The performance of the Total Galactose kit is comparable to other tests used for newborn screening. However, we could significantly reduce the costs per newborn and reduce unnecessary production of waste, by thorough validation and modification of the assay procedures.展开更多
文摘Galactosemia is an autosomal recessive disorder caused by deficient or absent activities of one of the three enzymes involved in the galactose metabolic pathway. The predominant form is classic type galactosemia caused by severe reduction or absence of the galactose- 1-phosphate uridyl transferase (GALT) enzyme. Coexistence of extrahepatic biliary atresia (EHBA) with Duarte 1 and 2 variants of galactosemia has not been described earlier. Here we report a case of EHBA with concordant Duarte 1 and 2 variants of galactosemia in an infant with cholestasis. Genetic analysis of the index patient for galactosemia revealed presence of Duarte 1/Duarte 2 variants of galactosemia with genotype N314D-L218L/N314D-G1105C-GI391A- G1323A-5’UTR-119delGTCA. Clinical evaluation of the patient showed the presence of EHBA. Henceforth, it may be hypothesized that EHBA may have a genetic basis with simultaneous involvement of the GALT gene.
基金This work has been devel-oped in the frame of the CNR-Bioinformatics Project
文摘We describe the GALT-Prot database and its related web-based application that have been developed to collect information about the structural and functional effects of mutations on the human enzyme galactose-l-phosphate uridyltransferase （GALT） involved in the genetic disease named galactosemia type I. Besides a list of missense mutations at gene and protein sequence levels, GALT-Prot reports the analysis results of mutant GALT structures. In addition to the structural information about the wild-type enzyme, the database also includes structures of over 100 single point mutants simulated by means of a computational procedure, and the analysis to each mutant was made with several bioinformatics programs in order to investigate the effect of the mutations. The web-based interface allows querying of the database, and several links are also provided in order to guarantee a high integration with other resources already present on the web. Moreover, the architecture of the database and the web application is flexible and can be easily adapted to store data related to other proteins with point mutations. GALT-Prot is freely available at http：//bioinformatica.isa.cnr.it/GALT/.
文摘Background:Galactosemia due to complete or near-complete galactose-l-phosphate uridyltransferase(GALT)deficiency was the first disorder added to the pioneering newborn screening panel besides phenylketonuria.In the last 50 years,many criticisms have been focused on the opportunity of its inclusion.Consequently,long-term single center experiences with this issue are generally lacking.Methods:We reviewed the outcome of newborn screening for hypergalactosemia performed at our department since 1982 and the correspondent long-term clinical outcome.Results:Among 1123909 newborns screened for hypergalactosemia,33 showed abnormal results confirmed at second tier test.Thirteen patients were affected with classic galactosemia,8 partial GALT deficiency,3 severe galactokinase deficiency,7 transient galactosemia,one congenital porto-systemic shunt,and one glucose transporter 2 deficiency.Acute neonatal liver failure in the late first week of life(5.8±1.1 days)unavoidably complicated the clinical course of classic galactosemia,unless in three second-born siblings treated on the basis of presumptive diagnosis immediately after newborn screening sample collection on day 3.Despite early treatment and longterm steadily normal peripheral blood galactose,77%of patients with severe GALT deficiency present mild to severe intellectual disabilities.All patients with partial GALT deficiency showed normal intellectual development on a regular diet,as well as patients with galactokinase deficiency under treatment.Conclusions:Availability of screening results within the fifth day after birth would allow the prevention of acute decompensation in classic galactosemia.A systematic diagnostic work-up in all positive newborns is essential to unravel the etiology of hypergalactosemia.
文摘Most newborn screening laboratories use CE-marked or FDA-approved test-kits, like in routine clinical chemistry. National regulations require only minimal evaluation from the customer, if the test-kits are used as specified by the manufacturer. The microtiter-based kit-concept is often based on the perception, that the laboratory always processes whole microtiter plates. However, in the daily routine, this is rather a rare exception, which leads to much higher costs per newborn, compared to the costs per assay in the test-kits. In addition the amount of wasted resources is quite high. Performance of the Neonatal Total Galactose kit from Perkin Elmer was tested. We have determined specificity, limit of detection (LOD), limit of quantitation (LOQ), intra and inter assay variation, recovery, stability of measuring signal and reagents. Results were also compared with the Astoria Pacific Spot Check System. In addition, we had (by chance) the opportunity to test 2 kits, which were already expired for more than 3 years. LOD was 165 - 306 μmol/L and LOQ 475 - 703 μmol/L, depending on the definition of LOD/LOQ. Mean recovery was 112.8%, intra assay CVs were 11.3, 7.3, 4.0, and 3.0, and inter assay CVs 28.7, 15.9, 7.8, and 9.3, at 220, 590, 1200, and 2060 μmol/L respectively. Reconstituted and mixed reagents must be used within some hours, and were unstable even if stored at -20℃. However, if the reconstituted galactose substrate reagent and galactose oxidase reagent were only mixed according to the daily requirements, and the rest stored separately at -20℃, they were stable for at least 12 days. The performance of the expired test-kits did not differ from the others. The performance of the Total Galactose kit is comparable to other tests used for newborn screening. However, we could significantly reduce the costs per newborn and reduce unnecessary production of waste, by thorough validation and modification of the assay procedures.
