Galactosemia - Citizendia


Galactosemia Classification and external resources
Galactose
ICD-10	E 74.2
ICD-9	271.1
eMedicine	ped/818
MeSH	D005693

Galactosemia is a rare genetic metabolic disorder which affects an individual's ability to properly metabolize the sugar galactose. Galactose (Gal (also called brain sugar) is a type of Sugar which is less sweet than Glucose. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings E00-E35 - Endocrine diseases (E00-E07 Thyroid gland / Thyroid hormone ( Congenital iodine-deficiency syndrome ( The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. eMedicine is an online clinical medical knowledge base that was founded in 1996 by Scott Plantz and Richard Lavely two medical doctors Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Galactose (Gal (also called brain sugar) is a type of Sugar which is less sweet than Glucose.

Goppert first described the disease in 1917,^[1] with its cause as a defect in galactose metabolism being identified by a group led by Herman Kalckar in 1956. Herman Moritz Kalckar (1908 -1991 was a Danish biochemist who pioneered the study of Cellular respiration. ^[2]

Its incidence is about 1 per 47,000 births (classic type). It is much rarer in Japan and much more common in Italy, specifically the traveler region. For a topic outline on this subject see List of basic Japan topics. Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Galactosemia is also very common within the Irish Traveller population. This is attributed to consanguinity within a relatively small gene pool.

1 Cause
2 Types
3 Diagnosis
4 Treatment
5 References
6 External links

Cause

Lactose

Glucose

Axial hydroxyl group drawn in red. Lactose (also referred to as milk sugar) is a Sugar which is found most notably in Milk. Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology.

Lactose in food (such as dairy products) is broken down by the body into glucose and galactose. Lactose (also referred to as milk sugar) is a Sugar which is found most notably in Milk. A dairy is a facility for the extraction and processing of animal Milk &mdashmostly from goats or cows, but also from buffalo, Sheep Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. In individuals with galactosemia, the enzymes needed for further metabolism of galactose are severely diminished or missing entirely, leading to toxic levels of galactose to build up in the blood, resulting in hepatomegaly (an enlarged liver), cirrhosis, renal failure, cataracts, and brain damage. Hepatomegaly is the condition of having an enlarged Liver. It is a nonspecific medical sign having many causes which can broadly be broken down into Infection The liver is a vital organ in the human body and is present in Vertebrates and some other animals Cirrhosis is a consequence of chronic Liver Disease characterized by replacement of liver tissue by fibrous Scar tissue as well as regenerative Renal failure or kidney A cataract is a clouding that develops in the crystalline lens of the Eye or in its envelope varying in degree from slight to complete opacity Brain damage, or Acquired brain injury, is the destruction or degeneration of Brain cells. Without treatment, mortality in infants with galactosemia is about 75%.

The 4th carbon on Galactose has an axial hydroxyl (-OH) group. Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. This causes Galactose to favor the open form as it is more stable than the closed form. This leaves an aldehyde (O=CH-) group available to react with nucleophiles, particularly proteins which contain amino (-NH2) groups, in the body. An aldehyde is an organic compound containing a terminal Carbonyl group. Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. This uncontrolled reactivity gives way to glycolation. Glycolation causes disease by altering the structure of proteins in ways that were not intended for biochemical processes.

Types

Galactose is converted into glucose by the action of three enzymes, known as the Leloir pathway. Accordingly, there are 3 known types of Galactosemia; type 1, 2 and 3:

Type	Diseases Database	OMIM	Gene	Locus	Enzyme	Name
Type 1	5056	230400	GALT	9p13	galactose-1-phosphate uridyl transferase	classic galactosemia
Type 2	29829	230200	GALK1	17q24	galactokinase	galactokinase deficiency
Type 3	29842	230350	GALE	1p36-p35	UDP galactose epimerase	galactose epimerase deficiency, UDP-Galactose-4-epimerase deficiency

The order of these three types is not the same as the order that the enzymes are encountered by galactose on its metabolic path (which is closer to GALK, GALT, and then GALE, though many variations can occur. The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. The Mendelian Inheritance in Man project is a Database that catalogues all the known Diseases with a genetic component, and—when possible—links them In the fields of Genetics and Evolutionary computation, a locus (plural loci) is a fixed position on a Chromosome such as the position of a Galactose-1-phosphate uridyl transferase (or GALT) is an Enzyme ( responsible for converting ingested Galactose to Glucose. Galactose-1-phosphate uridylyltransferase galactosemia (or Galactosemia type 1) is the most common type of Galactosemia. Galactokinase ( is a Phosphotransferase that catalyzes the Phosphorylation of d- Galactose to d- Galactose-1-phosphate. Galactokinase deficiency, also known as Galactosemia type 2 or GALK deficiency, is marked by an accumulation of Galactose and Galactitol secondary UDP galactose epimerase is an enzyme associated with type 3 Galactosemia. Galactose epimerase deficiency, also known as GALE deficiency, Galactosemia III and UDP-galactose-4-epimerase deficiency, is a rare form of Galactosemia )

Diagnosis

Infants are now routinely screened for galactosemia in the United States, and the diagnosis is made while the person is still an infant.

Treatment

The only treatment for classic galactosemia is eliminating lactose and galactose from the diet. Even with an early diagnosis and a restricted diet, however, some individuals with galactosemia experience long-term complications such as speech difficulties, learning disabilities, neurological impairment (e. In the United States and Canada, the term learning disability (LD refers to a group of disorders that affect a broad range of academic and functional skills including g. tremors, etc), and in girls, ovarian failure. These complications are treated if they appear in a manner similar to the way they would be treated in a non-galactosemic. Such complications have not been associated with Duarte galactosemia, and many individuals with Duarte galactosemia do not need to restrict their diet at all. Infants with classic galactosemia cannot be breast-fed due to lactose in human breast milk and are usually fed a soy-based formula. ^[3]

Galactosemia is sometimes confused with lactose intolerance, but galactosemia is a more serious condition. Lactose intolerance is the inability to metabolize Lactose, a sugar found in Milk and other Dairy products because the required enzyme Lactose intolerant individuals have an acquired or inherited shortage of the enzyme lactase, and experience abdominal pains after ingesting dairy products, but no long-term effects. Lactase (LCT a part of the β-galactosidase family of Enzymes is a Glycoside hydrolase involved in the Hydrolysis In contrast, a galactosemic individual who consumes galactose can cause permanent damage to their bodies.

Long term complication of galactosemia includes:

For a thorough scientific overview of galactosemia, one can consult chapter 72 of OMMBID^[4]. Ataxia (from Greek α- as a negative prefix + -τάξις, meaning "lack of order" is a neurological sign and symptom consisting Dysmetria ( Greek: "difficult to measure" refers to a lack of coordination of movement typified by the undershoot and/or overshoot of intended position with the hand Osteopenia is a condition where Bone mineral density is lower than normal Premature Ovarian Failure (POF also known as primary ovarian insufficiency, is the loss of function of the Ovaries before age 40 A cataract is a clouding that develops in the crystalline lens of the Eye or in its envelope varying in degree from slight to complete opacity For more online resources and references, see inborn error of metabolism. Inborn errors of metabolism comprise a large class of genetic Diseases involving disorders of Metabolism.

References

^ Goppert F. Galaktosurie nach Milchzuckergabe bei angeborenem, familiaerem chronischem Leberleiden. Klin Wschr 1917;54:473-477.
^ Isselbacher KJ, Anderson EP, Kurahashi K, Kalckar HM (1956). "Congenital galactosemia, a single enzymatic block in galactose metabolism". Science 13 (123): 635-6. PMID 13311516.
^ Breastfeeding: Diseases and Conditions: Contraindicators | DNPA
^ Charles Scriver, Beaudet, A. Charles Robert Scriver, CC, GOQ, MDCM FRS FRSC (born November 7, 1930) is an eminent Canadian Pediatrician L. , Valle, D. , Sly, W. S. , Vogelstein, B. , Childs, B. , Kinzler, K. W. (2006). The Online Metabolic and Molecular Bases of Inherited Disease. New York: McGraw-Hill. - Free summaries of 255 chapters, full text through many universities and organizations. Also, the OMMBID blog.

External links

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