Galactosemia is a genetic disease of a galactose metabolic abnormalities.Galactosemia, 1 - galactose uridine turn acyl shift the enzyme defect, and 1 - galactose and galactitol deposition and disease, red blood cells and liver enzyme changes, the enzyme has several variants. Liver, kidney, eye lens and brain tissue is the main organ involved. Children suffering from galactosemia is more than normal at birth, and vomiting soon after birth, not feeding, diarrhea, followed by jaundice and hepatomegaly. Children with slow growth, and not gain weight. Urine check for protein tube. Poor mental development. Also have low blood sugar caused by convulsions, cataracts, hepatomegaly, cirrhosis of the liver. Clotting substances caused by the reduced pediatric skin a number of bleeding or bleeding.
Galactosemia - an overview of diseaseGalactosemia galactosemia human genotype genetic metabolic defects is due to the lack of 1 - galactose to UDP-acyl transferase, resulting in the baby can not galactose metabolism of milk lactose decomposition. This is a hereditary disease of the number of galactose in the blood and urine. The main symptoms of nutritional disorders, cataract, mental retardation, and hepatosplenomegaly, and so on. The disease occurs in the congenital lack of semi-lactose -1 - phosphate uridine transferase. Galactose in the food, the symptoms can be improved. Adult uridine diphosphate - galactose pyrophosphate enzyme (UDP-galacto-sepyrophosphorylase) can galactose -1 - phosphate is converted to UDP galactose, galactose does not accumulate.
Children suffering from galactosemia is more than normal at birth, and vomiting soon after birth, not feeding, diarrhea, followed by jaundice and hepatomegaly. Children with slow growth, and not gain weight. Urine check for protein tube. Poor mental development. Also have low blood sugar caused by convulsions, cataracts, hepatomegaly, cirrhosis of the liver. Clotting substances caused by the reduced pediatric skin a number of bleeding or bleeding.
Should therefore be careful not to next of kin marriage. Other born children, if the above symptoms should go to hospital for treatment, check blood, urine galactose content to help diagnosis, once diagnosed should begin treatment, the sooner the better treatment, so as to avoid unrecoverable brain, eyes, liver and kidney damage to vital organs. Stop breastfeeding food and cereal instead. In addition to vitamin supplements, the time to add other complementary food. Pediatric symptom control milk diet can be gradually improved.
Galactosemia - pathogenesisThe human galactosemia, an autosomal recessive genetic disease. Human milk and milk contains lactose. Lactose into the body is broken down into glucose and galactose. Normal infants have the necessary enzymes, galactose can be broken down use. Infants suffering from galactosemia, this enzyme genotype is recessive homozygosity (gg), due to the lack of this essential enzyme, can not use galactose, so the content of galactose in the blood increased vomiting, diarrhea, hepatomegaly, cataracts, growth retardation, mental retardation and other symptoms. If we do not control, will die in infancy. If diagnosed early, the food does not contain lactose and galactose, the baby can be normal development. If it is found later, the liver has been damaged, occurs cataracts and mental retardation, although for the treatment, it is difficult to recover. Now know that galactosemia children of the missing enzyme, called galactose 1 - phosphate transfer the uridine acyl enzyme (galactose-1-phosphateuridyltransferase Gl-PUT,). Galactosemia infants suffering from congenital metabolic disease, an autosomal recessive inheritance, gene frequency of 32 ‰, group the incidence rate of 1/100 000.
Under normal circumstances, the infant breast-feeding, milk contains lactose by digestive enzymes break down the galactose and glucose, galactose to form galactose 1 - phosphate kinase, and then in the liver by galactose -1 - phosphate uridine transferase (galactose-1-phosthateuridyltransreraseGal-1-PUT) the catalytic conversion of glucose 1 - phosphate, enter glycolysis via. Gal-1-PUT, due to mutations caused structural changes and loss of function, galactose metabolism is blocked, the accumulation of galactose in the blood and tissues, and with the urine. Intermediates galactose 1 - phosphate (Gal-1-P) is harmful to the cell mainly affects the liver, kidney, brain and lens, the children breast-feeding after a few days of vomiting, diarrhea, dehydration and other symptoms. A week later, the enlargement of the liver, jaundice, ascites, and cataracts. A few months later mental retardation, and often premature death. This is galactosemia. If the feed to milk and dairy products, baby to fully develop normally after birth. Stop dairy foods can improve symptoms, but intelligence can not be restored.
1 - galactose cytotoxicity, inhibition of many enzymes in the pathway of glucose metabolism, in particular, is not l-phosphate conversion of glucose to glucose 6 - phosphate glucose phosphate mutase role Inhibitory resistance off the process of glycogenolysis; high concentrations of 1 - galactose also inhibited glucose gluconeogenesis process, thereby showing clinical symptoms of hypoglycemia. Galactose into the crystal aldose reductase are duly restored galactitol deposited in the crystal cause the crystal osmotic pressure, increased water content, amino acid transport and protein synthesis decreased metabolic abnormalities, and ultimately the formation of cataracts. Liver, kidney, brain and other tissues of the children of this type has a large number of 1 - galactose and galactitol deposition, these abnormal metabolites change the tissue penetration of the molar concentration and energy metabolism, resulting in these impaired organ function. The detailed mechanism is not fully understood.
Galactosemia - clinical manifestationsGalactosemia few weeks after birth, liver disease, including cholestasis, extensive fatty degeneration, inflammatory cell infiltration, after the formation of false bile duct, the false gland hyperplasia, liver cell damage, false gland hyperplasia galactosemia characteristics, but without specificity. Thin fibrous tissue proliferation with disease progression. Periportal fibrous tissue proliferation began, after an extension constitutes a bridge-like connection to the portal area, after the formation of regenerative nodules in cirrhosis of the liver process of change and alcoholic cirrhosis, the entire disease process has never been obvious inflammation cell infiltration. Addition to liver disease, renal cortex, medulla junction tubular expansion of portal hypertension can cause splenomegaly, mild brain lesions.The severity of disease vary widely, some children in the first lactation can be acute, fulminant disease is manifested as subacute after. Gastrointestinal symptoms, including jaundice, loss of appetite, bloating, diarrhea, vomiting, low blood sugar. Ascites approximately 2 to 5 weeks after birth a few days to a cataract, such as pregnant mothers eat during the milk too much, you can have jaundice after birth.
Vomiting, poor feeding, weight gain and drowsiness and other symptoms typical person in a few days after the feeding of dairy, and then showing jaundice and enlargement of the liver can not be timely diagnosis and continue to feed the dairy, will lead to further deterioration in the two ~ 5 weeks of the end-stage symptoms of ascites, liver failure and bleeding. With a slit lamp examination, you can find in the early onset of cataract formation in the crystal. About 30% to 50% in the course of one week or so concurrent Escherichia coli sepsis, the condition is more serious without the timely diagnosis and treatment of children with most of the mortality in the neonatal period. The small number of children with symptoms of minor and only mild gastrointestinal symptoms after eating dairy, but if they continue to use dairy foods in the young infancy gradually showing growth retardation and intellectual development of backward cirrhosis and cataracts, and other signs.
Galactosemia - health screeningGroup screening can not only achieve the purpose of early diagnosis and treatment of newborns, the neonatal period screening of galactosemia (1) can also provide information on genetic counseling and family planning. Most screening centers are two alternative methods: the Beufler test for the detection of blood droplets paper galactose 1 - phosphate uridine acyl transferase activity, its drawback is that the false positive rate is too high; Paigen test is used to detect blood drops paper galactose and galactose-l-phosphoric acid semi-quantitative method, the advantage is that very few false positives, and three kinds of enzyme defects can be detected. Screening by MS spectrometer (tandemMS) is particularly convenient, correct.(2) reducing sugar determination in the urine of children with suspected symptoms of the importance of timely check their urine whether there are reducing sugars. May be discharged in the urine reducing sugar more categories, such as glucose, galactose, lactose, fructose and pentose sugar, when the qualitative test was positive, further use of paper or thin layer chromatography methods were identified.
(3) Enzymatic diagnosis of peripheral blood red, white blood cells, skin fibroblasts or liver biopsy, etc. available for determination of enzyme activity with the most convenient to red blood cells. The disease activity in children with homozygous absence or very low; heterozygous carriers of the enzyme activity, compared with 50 percent of normal. In recent years, the characteristics of the enzyme defect, discovered variant of this disease. Among them, the Duarte type is most prevalent. Homozygous Duarte enzyme activity for 50% of normal, heterozygous Duarte type up to 75%, not showing clinical symptoms, it is only through group screening before they can found. "Negro" a lack of red blood cell transferase activity, liver, intestines and other organizations are still part of the activity exists, the clinical asymptomatic.
(4) Other necessary, liver function, blood coagulation, blood glucose, serum electrolytes and blood and urine cultures and other projects in order to facilitate diagnosis.
Galactosemia - treatment of diseaseGalactosemia, an early diagnosis should exclude the galactose in the diet. Some have argued that the 8-year-old can no longer restricted diet, but in general should be life-long insisted. After timely treatment, cataracts, hepatomegaly, and cirrhosis can be reversed. Is important, asymptomatic homozygous women, food of high dairy and food galactose in the blood increased female fertility baby may be suffering from galactosemia, in particular during the previously born more than half of the the galactosemia baby's mother, during pregnancy should limit galactose intake.Limit dairy immediately disabled the milk, switch to soy milk, rice, and supplemented by vitamins, fat and other nutrients necessary for substances in milk to break down galactose, honey trisaccharide (raffinose) and stachyose (stachyose) , but not by human intestinal absorption so harmful to the treatment is usually 3 to 4 days to see the improvement of clinical symptoms in limiting dairy, liver function improved after one week. Must avoid all food that may contain milk and some of the lactose-containing fruits and vegetables such as watermelon, tomatoes, etc. After the children began to feed auxiliary food.
Support the treatment of venous lost to glucose, fresh plasma, pay attention to the added electrolyte.
4 children with sepsis, the antibiotic should be the use of appropriate antibiotics and active support treatment.
Galactosemia - Disease PreventionThe galactosemia pathogenesis is not yet entirely clear, preventive measures with reference to genetic diseases. Has proved the sick child skin fibroblasts, Gal-1-PUT enzyme abnormalities by enzymatic analysis of cultured amniotic fluid cells in Gal-1-PUT activity to reduce, can make a prenatal diagnosis. Nadler, etc. use this method for prenatal diagnosis because of the simple method of newborn screening and if early detection and control diet, the normal development of sick children can therefore whether it should do prenatal diagnosis remains controversial.The prognosis of children depends upon early diagnosis and treatment. Without proper treatment, most of the deaths during the neonatal period, the average life expectancy of about six weeks, even if spared the future legacy smart developmental disorders. Access to early diagnosis of children with growth and development is mostly normal, but the majority of adult learning disabilities, language difficulties or behavioral abnormalities and other issues. Female patients in the elderly almost all gonadal function occurs, the reasons are not very clear.
The galactokinase lack sex half galactosemia galactose kinase encoding gene is located 17q2l ~ q22, whose mutations are rare. The children body of the patient accumulation of galactose-l-phosphate, therefore, no liver, and brain damage. Galactose in the crystal aldose reductase converted to galactitol after the cause cataracts, so patients should avoid the intake of lactose, food for life.
Uridine diphosphate galactose -4 - Table isomerase deficiency is rare in this type of sexual half galactosemia, uridine diphosphate galactose -4 - isomerase encoding gene is located lpter ~ lp32, according to the enzyme deficiency involving the organization of different can be divided into two subtypes: Most children with red, white blood cells within a table isomerase deficiency and galactose-l-phosphate levels increased, but as the normal enzyme activity in fibroblasts and liver, so the children do not exhibit any symptoms , normal growth and development; while a few children with enzyme defects involving a variety of tissues and organs, the clinical manifestations resemble transferase lack of sex half galactosemia, erythrocyte transferase activity of normal and galactose 1 - phosphate increased data can be identified. This type should be monitored regularly during treatment red blood cell galactose-l-phosphate.
Galactosemia - Drugs and composition
Galactosemia, galactose (CH2OH (CHOH) 4CHO) is a monosaccharide, can be found in dairy products or sugar beets. Galactose is a monosaccharide composition of the six carbon and an aldehyde, classified as aldose and hexose. Galactose is the composition of the lactose in the milk of mammals have been found by D-galactose polysaccharide from the snail, frog eggs and bovine lung. It is often in the form of the D-galactosidase in the brain and nerve tissue, is also an important component of the glycoprotein. Galactose polysaccharide in the form in plants often exist in a variety of vegetable gum, such as K-carrageenan in the red algae polysaccharide composed of D-galactose and 3,6 - anhydro-D-galactose. Free galactose present in the berries of the Ivy League. Galactose as white crystals. D-galactose and L-galactose are naturally occurring. D-galactose is generally as part of the structure of lactose in milk, the lactose in milk by the body is decomposed into glucose and galactose absorption and utilization. Because it contains calories, it will also be used as a nutritional sweetener. Galactose is part of the lactose molecule and the other half is glucose. In the catalysis of the β-lactase, galactose can be obtained from the hydrolysis of lactose. Bifidobacteria ferment lactose to produce galactose, constitute the composition of the brain systems Cerebroside, rapid growth is closely related to the back of the head and the baby is born.
Alias: D (+)-Glactose, Galactose; brainsugar; d-galactose; D-Galactopyranose
Molecular formula: C6H12O6
Molecular Weight: 180.16
Appearance: white or almost white powder
Content (HPLC): 98% min
