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Galactosemia
Galactosemia is a disorder that affects how the body
processes a simple sugar called galactose. A small amount of
galactose is present in many foods. It is primarily part of a larger
sugar called lactose, which is found in all dairy products and many
baby formulas. The signs and symptoms of galactosemia result
from an inability to use galactose to produce energy.
Researchers have identified several types of galactosemia.
These conditions are each caused by mutations in a particular
gene and affect different enzymes involved in breaking down
galactose.
Classic galactosemia, also known as type I, is the most
common and most severe form of the condition. If infants with
classic galactosemia are not treated promptly with a low-galactose
diet, life-threatening complications appear within a few days after
birth. Affected infants typically develop feeding difficulties, a lack
of energy (lethargy), a failure to gain weight and grow as expected
(failure to thrive), yellowing of the skin and whites of the eyes
(jaundice), liver damage, and abnormal bleeding. Other serious
complications of this condition can include overwhelming
bacterial infections (sepsis) and shock. Affected children are also
at increased risk of delayed development, clouding of the lens of
the eye (cataract), speech difficulties, and intellectual disability.
Females with classic galactosemia may develop reproductive
problems caused by an early loss of function of the ovaries
(premature ovarian insufficiency).
Galactosemia type II (also called galactokinase deficiency)
and type III (also called galactose epimerase deficiency) cause
different patterns of signs and symptoms. Galactosemia type II
causes fewer medical problems than the classic type. Affected
infants develop cataracts but otherwise experience few long-term
complications. The signs and symptoms of galactosemia type III
vary from mild to severe and can include cataracts, delayed
growth and development, intellectual disability, liver disease, and
kidney problems.
Frequency
Classic galactosemia occurs in 1 in 30,000 to 60,000
newborns. Galactosemia type II and type III are less common;
type II probably affects fewer than 1 in 100,000 newborns and
type III appears to be very rare.
Causes
Mutations in the GALT, GALK1, and GALE genes cause
galactosemia. These genes provide instructions for making
enzymes that are essential for processing galactose obtained from
the diet. These enzymes break down galactose into another simple
sugar, glucose, and other molecules that the body can store or use
for energy.
Mutations in the GALT gene cause classic galactosemia (type
I). Most of these genetic changes almost completely eliminate the
activity of the enzyme produced from the GALT gene, preventing
the normal processing of galactose and resulting in the life-
threatening signs and symptoms of this disorder. Another GALT
gene mutation, known as the Duarte variant, reduces but does not
eliminate the activity of the enzyme. People with the Duarte
variant tend to have much milder features of galactosemia.
Galactosemia type II results from mutations in the GALK1
gene, while mutations in the GALE gene underlie galactosemia
type III. Like the enzyme produced from the GALT gene, the
enzymes made from the GALK1 and GALE genes play important
roles in processing galactose. A shortage of any of these critical
enzymes allows galactose and related compounds to build up to
toxic levels in the body. The accumulation of these substances
damages tissues and organs, leading to the characteristic features
of galactosemia.
Inheritance Pattern
This condition is inherited in an autosomal recessive pattern,
which means both copies of the gene in each cell have mutations.
The parents of an individual with an autosomal recessive
condition each carry one copy of the mutated gene, but they
typically do not show signs and symptoms of the condition.
Here is another Scientific Writing for Galactosemia

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Scientific Writing for Galactosemia Health Conditions Dehradun, Uttrakhand

  • 1. Galactosemia Galactosemia is a disorder that affects how the body processes a simple sugar called galactose. A small amount of galactose is present in many foods. It is primarily part of a larger sugar called lactose, which is found in all dairy products and many baby formulas. The signs and symptoms of galactosemia result from an inability to use galactose to produce energy. Researchers have identified several types of galactosemia. These conditions are each caused by mutations in a particular gene and affect different enzymes involved in breaking down galactose. Classic galactosemia, also known as type I, is the most common and most severe form of the condition. If infants with classic galactosemia are not treated promptly with a low-galactose diet, life-threatening complications appear within a few days after birth. Affected infants typically develop feeding difficulties, a lack of energy (lethargy), a failure to gain weight and grow as expected (failure to thrive), yellowing of the skin and whites of the eyes (jaundice), liver damage, and abnormal bleeding. Other serious complications of this condition can include overwhelming
  • 2. bacterial infections (sepsis) and shock. Affected children are also at increased risk of delayed development, clouding of the lens of the eye (cataract), speech difficulties, and intellectual disability. Females with classic galactosemia may develop reproductive problems caused by an early loss of function of the ovaries (premature ovarian insufficiency). Galactosemia type II (also called galactokinase deficiency) and type III (also called galactose epimerase deficiency) cause different patterns of signs and symptoms. Galactosemia type II causes fewer medical problems than the classic type. Affected infants develop cataracts but otherwise experience few long-term complications. The signs and symptoms of galactosemia type III vary from mild to severe and can include cataracts, delayed growth and development, intellectual disability, liver disease, and kidney problems. Frequency Classic galactosemia occurs in 1 in 30,000 to 60,000 newborns. Galactosemia type II and type III are less common; type II probably affects fewer than 1 in 100,000 newborns and type III appears to be very rare.
  • 3. Causes Mutations in the GALT, GALK1, and GALE genes cause galactosemia. These genes provide instructions for making enzymes that are essential for processing galactose obtained from the diet. These enzymes break down galactose into another simple sugar, glucose, and other molecules that the body can store or use for energy. Mutations in the GALT gene cause classic galactosemia (type I). Most of these genetic changes almost completely eliminate the activity of the enzyme produced from the GALT gene, preventing the normal processing of galactose and resulting in the life- threatening signs and symptoms of this disorder. Another GALT gene mutation, known as the Duarte variant, reduces but does not eliminate the activity of the enzyme. People with the Duarte variant tend to have much milder features of galactosemia. Galactosemia type II results from mutations in the GALK1 gene, while mutations in the GALE gene underlie galactosemia type III. Like the enzyme produced from the GALT gene, the enzymes made from the GALK1 and GALE genes play important roles in processing galactose. A shortage of any of these critical enzymes allows galactose and related compounds to build up to
  • 4. toxic levels in the body. The accumulation of these substances damages tissues and organs, leading to the characteristic features of galactosemia. Inheritance Pattern This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Here is another Scientific Writing for Galactosemia