Name short: GALT

Name long: Galactosemia

Description: Galactosemia is a disorder that affects how the body processes a simple sugar 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).

Incidence in the US 2001-2010: 770 in 41.1 million screens (20 cases per million).

Implicated genes:
Galactose-1-phosphate uridyltransferase, GALT


Variants in GALT (see gnomAD page):
total variable positions: 331
rare variants: 0
common variants: 0
Allele frequency of rare (<0.001) variants and the implied number of homozygotes and compound heterozygotes, per million births (under the naive assumption that gnomAD captures all variants present in the human population; PSC = premature stop codon):

Population All rare variants Rare, resulting in PSC Rare, not intronic and not silent Known disease related All presumably detrimental
all 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
afr 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
amr 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
asj 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
eas 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
fin 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
nfe 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
oth 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0
sas 0 => 0 0 => 0 0 => 0 0 => 0 0 => 0


Expected number of homozygotes/compound heterozygotes in a demographic profile close to the US, using all known (as in, listed in gnomAD) rare nontrivial variants as causative variants: 0.

Expected number of homozygotes/compound heterozygotes in a demographic profile close to the US, using all presumably harmful variants as causative variants: 0.

Enzyme structure. Representative chain shown as white cartoon, with positions of known mutations shown as red sticks. Blue: physiological ions. Pink: substrates and cofactors.



Total estimated number of casses per million (all presumably harmful variants): 0.

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