Newborn Screening For Galactosemia Research Articles

Newborn screening for galactosemia: a 30-year single center experience.

Galactosemia due to complete or near-complete galactose-1-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. We reviewed the outcome of newborn screening for hypergalactosemia performed at our department since 1982 and the correspondent long-term clinical outcome. Among 1 123 909 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 long-term 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. 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.

Erratum to: Newborn Screening for Galactosemia in the United States: Looking Back, Looking Around, and Looking Ahead.

It has been 50 years since the first newborn screening (NBS) test for galactosemia was conducted in Oregon, and almost 10 years since the last US state added galactosemia to their NBS panel. During that time an estimated >2,500 babies with classic galactosemia have been identified by NBS. Most of these infants were spared the trauma of acute disease by early diagnosis and intervention, and many are alive today because of NBS. Newborn screening for galactosemia is a success story, but not yet a story with a completely happy ending. NBS, follow-up testing, and intervention for galactosemia continue to present challenges that highlight gaps in our knowledge. Here we compare galactosemia screening and follow-up data from 39 NBS programs gathered from the states directly or from public sources. On some matters the programs agreed: for example, those providing relevant data all identify classic galactosemia in close to 1/50,000 newborns and recommend immediate and lifelong dietary restriction of galactose for those infants. On other matters the programs disagree. For example, Duarte galactosemia (DG) detection rates vary dramatically among states, largely reflecting differences in screening approach. For infants diagnosed with DG, >80% of the programs surveyed recommend complete or partial dietary galactose restriction for the first year of life, or give mixed recommendations; <20% recommend no intervention. This disparity presents an ongoing dilemma for families and healthcare providers that could and should be resolved.

Literature Review and Outcome of Classic Galactosemia Diagnosed in the Neonatal Period

The aim of this study was to evaluate the features and outcome of classic galactosemia diagnosed in the neonatal period. A retrospective study was carried out on 22 newborns with classic galactosemia who were followed-up in a tertiary neonatal intensive care unit from January 2005 to January 2011. During the study period, 22 (18 boys, 4 girls) newborns were diagnosed with classic galactosemia. The median gestational age was 38 weeks (31 - 42) with a median age of 13 (3 - 23) days on admission. Major presenting symptoms were hepatomegaly (n = 22, 100%), jaundice [n = 19, 86%; including (n = 14, 63%) indirect and (n = 8, 36%) direct hyperbilirubinemia], vomiting (n = 17, 77%), and nuclear cataract (n = 15, 68%). Liver dysfunction (n = 22, 100%), Escherichia coli sepsis (n = 10), purpura fulminans (n = 1), hemophagocytosis (n = 1), and long QT syndrome (n = 1) were also noted. Cataract resolved in 11 (73%) patients with galactose-restricted diet in the first months. Four patients were operated for cataracts. Neurodevelopmental evaluation showed mild psychomotor retardation in one patient, learning disabilities in five, and developmental delay in three. None died from galactosemia or its complications. Patients who were diagnosed before 17 days did not require cataract operation. Early diagnosis of galactosemia and treatment with a galactose-restricted diet could partially prevent and recover complications of the disease, but not all of them. Cataracts can develop even in the first few weeks of life. Early diagnosis seems important in the prevention of severe cataracts. Therefore, newborn screening for galactosemia should improve morbidity.

Newborn screening for galactosemia by a second‐tier multiplex enzyme assay using UPLC‐MS/MS in dried blood spots

Galactosemia is one of the most important inherited metabolic disorders detected by newborn screening tests. Abnormal results during screening should be confirmed by enzyme activity assays. Recently, we developed a multiplex enzyme assay for galactosemia in erythrocytes using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In this study, we proposed a second-tier multiplex enzyme assay for galactosemia that can be directly applied to dried blood spots (DBSs). Supernatants from two rehydrated-punched 3.2-mm DBSs were incubated with a reaction mixture containing [¹³C6]galactose, [¹³C2]galactose-1-phosphate, and UDP-glucose as substrates for three galactose-metabolizing enzymes. After a 4-hour incubation, the end products from the combined reaction mixture, [¹³C6]galactose-1-phosphate, UDP-[¹³C2]galactose, and UDP-galactose, were simultaneously measured using UPLC-MS/MS. Substrates, products, and internal standards from the mixture of the three enzyme reactions were clearly separated in the UPLC-MS/MS system, with an injection cycle time of 10 min. Intra- and inter-assay imprecisions of the UPLC-MS/MS were 8.4-14.8% and 13.2-15.7% CV, respectively. Enzyme activities in DBSs from 37 normal individuals and 10 patients with enzyme deficiencies were analyzed. DBSs from galactosemia patients showed consistently lower enzyme activities as compared to those of normal individuals. In conclusion, multiplex enzyme assays using UPLC-MS/MS can be successfully applied to DBS analysis. This method allows a fast and effective second-tier test for newborns showing abnormal screening results.

Rapid quantification of conjugated and unconjugated bile acids and C27 precursors in dried blood spots and small volumes of serum

The aim of the study was to develop a method for fast and reliable diagnosis of peroxisomal diseases and to facilitate differential diagnosis of cholestatic hepatopathy. For the quantification of bile acids and their conjugates as well as C(27) precursors di- and trihydroxycholestanoic acid (DHCA, THCA), in small pediatric blood samples we combined HPLC separation on a reverse-phase C18 column with ESI-MS/MS analysis in the negative ion mode. Analysis was done with good precision (CV 3,7%-11.1%) and sufficient sensitivity (LOQ: 11-91 nmol/L) without derivatization. Complete analysis of 17 free and conjugated bile acids from dried blood spots and 10 microL serum samples, respectively, was performed within 12 min. Measurement of conjugated primary bile acids plus DHCA and THCA as well as ursodeoxycholic acid was done in 4.5 min. In blood spots of healthy newborns, conjugated primary bile acids were found in the range of 0.01 to 2.01 micromol/L. Concentrations of C(27) precursors were below the detection limit in normal controls. DHCA and THCA were specifically elevated in cases of peroxysomal defects and one Zellweger patient.

Newborn Screening for Galactosemia: A Review of 5 Years of Data and Audit of a Revised Reporting Approach

Availability of the galactose-1-phosphate uridyltransferase (GALT) assay for newborn (NB) screening has improved identification of classic galactosemia. Previously defined critical cutoffs for total galactose (Gal), typically 1.110 mmol/L (20 mg/dL), are still in use in laboratories measuring total Gal for the diagnosis of nonclassic galactosemias. Urgent notification/referral to a treatment center follows, although few of the NBs will need treatment. We reviewed all NB galactosemia-screening results and their corresponding clinical outcomes over a 5-year period (first phase, 1.32 x 10(6) NBs) and then over a 2-year period (second phase, 274 960 NBs). Each NB was screened for Gal and GALT. When Gal was increased and/or GALT was deficient, testing for percentage galactose-1-phosphate and/or DNA testing for common GALT mutations were performed. Of 209 reported positive results, 89% did not indicate GALT deficiency. These non-GALT-deficient results represented mostly clinically benign cases with a Gal threshold of > or = 1.110 mmol/L (> or = 20 mg/dL). The positive predictive value of a GALT cutoff of < or = 40 micromol/L was 83%. After a protocol change that redefined a critical result as a GALT value < or = 40 micromol/L and/or a Gal value > or = 1.665 mmol/L (> or = 30 mg/dL), results were monitored for an additional 2 years. The new protocol dramatically reduced the number of urgent calls/referrals and reduced the total number of referrals by nearly half. Use of a GALT cutoff of < or = 40 micromol/L/L and a Gal cutoff of > or = 1.665 mmol/L (> or = 30 mg/dL) for urgent notification/referral dramatically reduces false positives and unnecessary follow-up, thereby reducing the stress on healthcare resources.

Duarte (DG) galactosemia: A pilot study of biochemical and neurodevelopmental assessment in children detected by newborn screening

Newborn screening for galactosemia has shown a high prevalence of partial galactose uridyl transferase deficiencies such as Duarte (DG) galactosemia. Study objective: To determine whether (a) there is any clinical impact of DG galactosemia on development (b) there is a relationship between outcome and biochemical parameters in patients who receive no treatment. Study population: Twenty-eight children with DG galactosemia. Group-I—17 children had a lactose restricted diet in the first year of life. Group-II—11 children had a regular diet since birth. Methods: Developmental, physical, and ophthalmologic assessments were completed on both DG groups. RBC gal-1-p and urine galactitol were monitored during the follow-up visits in every child with DG galactosemia. Gal-1-p, urine galactitol, liver function tests, and FSH were tested at the time of study visit. Results: The groups had statistically significant differences on RBC gal-1-p and urine galactitol at the 2 week, 1 month, 6 month, and 1 year time points. There was no statistical difference of gal-1-p or urine galactitol in group-I and -II at the time of study. The groups had statistically significant differences on adaptive scores, but not on language or IQ. None of the DG subjects had abnormal liver function at the time of diagnosis or the study visit. The FSH levels were normal. There were no statistically significant relationships between the first year metabolic values and developmental outcomes. Conclusions: The data presented here indicate that clinical and developmental outcomes in DG galactosemics are good regardless of any diet changes.

Molecular detection of galactosemia mutations by PCR-ELISA.

AbstractClassic galactosemia is an autosomal recessive disorder caused by the deficiency of galactose 1-phosphate uridyltransferase, GALT (EC 2.7.7.12) (1). It presents with vomiting and diarrhea in neonates within a few days of milk intake. Most patients develop jaundice and hepatic failure. If untreated, it is potentially lethal. Newborn screening for galactosemia is routine in all states in the USA and in many other countries. Elimination of dietary galactose is the main treatment. However, this does not prevent secondary complications such as growth retardation, mental retardation, dyspraxia, cataracts, ataxia, and ovarian failure later in life (2).KeywordsPolymerase Chain Reaction ProductHybridization ReactionClassic GalactosemiaIntended PrimerPolymerase Chain Reaction Thermal CyclingThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Evaluation of Mutation Scanning As A Confirmatory Test in Newborn Screening for Galactosemia

Evaluation of Mutation Scanning As A Confirmatory Test in Newborn Screening for Galactosemia

Minimizing false positive diagnoses in newborn screening for galactosemia.

Heat and humidity, rather than summertime heat alone, cause extensive loss of galactose-1-phosphate uridyltransferase activity in mailed blood spots and seem to account for false positive diagnoses of galactosemia. The spots are partially protected from the effects of atmospheric humidity if they are allowed to dry and then are sealed in a plastic freezer bag before being exposed to higher humidity. Conversely, extensive loss of transferase activity occurs if the samples are sealed in the bags before the spots are dry. The fluorescence from transferase activity can be monitored with greater sensitivity fluorometrically than visually. A simultaneous fluorometric determination of phosphoglucomutase activity reveals whether decreased transferase activity represents sample deterioration or galactosemia. Mg2+ and a sulfhydryl agent, such as dithiothreitol, are needed for activity of phosphoglucomutase, an enzyme in the sequence leading to the fluorescent substance (NADPH). They must be added in certain modifications of the assay.

Microdetermination of galactose and galactose 1-phosphate in dried blood spots

Newborn screening for galactosemia (galactose-1-phosphate uridyltransferase deficiency), as well as for other defects in galactose metabolism (galactokinase deficiency and uridine diphosphogalactose 4-epimerase deficiency), requires a method of determining both galactose and galactose 1-phosphate in dried blood. We have developed a sequential quantitative method for the microdetermination of galactose and galactose 1-phosphate that can be applied to 3-mm-diameter disks of dried blood and that can be used with a Technion Autoanalyser II equipped with a fluorometer. Galactose is determined by the fluorescence of NADH following treatment with β-galactose dehydrogenase and with the consequent reduction of NAD. The complete system includes alkaline phosphatase for the hydrolysis of galactose 1-phosphate, so that the total amounts of a galactose and galactose 1-phosphate are determined. For the measurement of galactose alone, alkaline phosphate is omitted from the system. The difference in fluorescence between that from the complete system and that from the alkaline phosphatase-omitted system yields the concentration of galactose 1-phosphate.

Newborn screening for galactosemia and other galactose metabolic defects

Summary Routine newborn screening is necessary for the effective diagnosis of galactosemia. The criticism that routine screening for galactosemia is unnecessary is based on the misconception that the diagnosis will almost always be made clinically, since the disease produces clinical manifestations in the infant. Acutally most newborn infants, detected by routine screening, were not suspected to have galactosemia, even when ill. Furthermore, some infants with clinically important transferase variants are not ill as neonates. In Massachusetts, a black infant who probably has the Negro variant form of galactosemia and an infant with the Rennes variant of galactosemia 6 were clinically normal at five days of age when detected by routine screening. Complications of galactosemia can occur in both variants if treatment is not given. In addition, galactokinase deficiency, which results in cataracts but not in acute illness, 32 cannot be detected on a clinical basis until the cataracts have become apparent, when it is too late for preventive therapy. The full impact of galactosemia on the newborn infant has become evident only since routine newborn screening has been initiated. It is now apparent that death associated with bacterial sepsis may occur in about 30% of those with untreated classical galactosemia. 4 In most of these deaths diagnosis and treatment were delayed until the second week of life. Consequently, screening for galactosemia should be performed on a blood specimen that is obtained no later than the third or fourth day of life and is delivered promptly to the screening laboratory. There should be sufficient medical back-up available to the laboratory so that the attending physician can be quickly contacted by telephone when an abnormality suggesting galactosemia is encountered. Further procedures should follow: (1) Urine should be tested for reducing substance. (2) If urinary reducing substance is present, galactosemia should be presumed; milk feedings should be discontinued; and blood and urine specimens should be sent to a laboratory for confirmatory testing. (3) If the infant is ill, bacterial cultures should be obtained and treatment for sepsis initiated. (4) If galactosemia is confirmed, treatment should be continued. Otherwise, treatment can be discontinued. Galactosemia screening should be routine for all newborn infants. It is a disorder with definite and severe complications, but one in which the complications can be prevented with simple and inexpensive treatment. When a test for galactose and gal-l-P, such as the Paigen assay, is also applied to the newborn blood specimen that is, submitted for PKU screening, galactosemia can be detected efficiently and effectively.