Home > Newborn Disorders > Galactosemia
Galactosemia
Names
Galactosemia
Classic galactosemia
Duarte galactosemia
Galactose-1-phosphate uridyl-transferase deficiency disease
Galactokinase (GALK) deficiency disease
UDP-galactose-4-epimerase (GALE) deficiency disease
Overview
Galactose is found in many foods and is produced when lactose is split by lactase into glucose and galactose. Three enzymes are involved in the metabolism of galactose into uridine diphosphate (UDP)-glucose and, ultimately, to carbon dioxide. Mutations of each of these genes can result in galactosemia:- Galactose-1-phosphate uridyl-transferase (GALT) deficiency results in Classic Galactosemia, where homozygotes have less than 5% enzyme activity. Duarte variant galactosemia, with between 10% and 25% activity, results from the compound heterozygote state with a GALT mutation and a Duarte allele.
- Galactokinase 1 (GALK1) deficiency may cause cataracts and pseudotumor cerebri.
- UDP-galactose-4-epimerase (GALE) deficiency can cause a benign form, in which the deficiency is found only in red blood cells and no symptoms result, and a severe form, in which the deficiency affects most tissues resulting in symptoms similar to classic galactosemia.
Symptoms of galactosemia are the result of inadequate energy production (due to lack of conversion to glucose) and accumulation of galactose and its metabolites (specifically galactose-1-phosphate). Accumulation of galactitol, the product of an accessory metabolic pathway, can result in cataracts and pseudotumor cerebri.
Prevalence
Classic galactosemia occurs in about 1/30,000 live births; Duarte variant occurs in about 1/16,000.Prenatal Testing
If the GALT mutations are known, then GALT enzyme activity or molecular genetic testing is possible.Clinical Characteristics
For classic galactosemia, symptoms develop shortly after starting to ingest milk or other lactose containing foods. With treatment, good health may be expected. Even with therapy, some patients with classic (G/G) galactosemia can have speech defects, poor intellectual function, neurologic deficits (predominantly extrapyramidal findings with ataxia), and ovarian failure with primary amenorrhea or early menopause. Without treatment, hepatic and neurologic injury and increased risk of sepsis may lead to death.Initial signs/symptoms may include:
- poor feeding,
- vomiting,
- diarrhea,
- jaundice,
- bleeding diasthesis,
- lethargy,
- abdominal distention with hepatomegaly, and
- increased risk of sepsis with gram negative organisms.
If not treated promptly, patients may experience:
- progressive liver failure,
- cataracts, and
- brain damage.
Follow-up on positive screening test
Patients with a positive screening test (GALT activity level < or = 2.0 U/gHb) or who are symptomatic should be on a lactose/galactose free diet until the galactose-1-phosphate uridyltransferase enzyme level and the galactosemia DNA panel has been completed. Patients with a positive screening test with a GALT activity level >2.0 do not need dietary change. If the galactose-1-phosphate uridyltransferase and the Utah galactosemia DNA panel is consistent with classical galactosemia (GG genotype with low activity level) dietary restriction of galactose should continue. All other genotypes, including Duarte galactosemia (DG), do not require dietary restriction. In Duarte galactosemia, the galactose-1-phosphate level may be elevated in the first year of life, but no deficits occur.Primary care management
Upon notification of the + screen
- Contact the family and evaluate the infant for related symptoms;
- Provide emergency treatment/referral for symptoms of poor feeding, lethargy, jaundice, vomiting, bulging fontanel;
- Discontinue breast or cow milk formula feeding, start feeding with Prosobee or Isomil soy formulas;
- To confirm the diagnosis, work with the following service(s): Utah Newborn Screening Program, (801-584-8256); See also Services below;
- For evaluation and ongoing collaborative management, consult the following service(s): Medical Genetics, (801-231-3599); See also Services below;
If the diagnosis is confirmed
- Educate the family regarding signs, symptoms, and the need for urgent care when the infant becomes ill;
- Assist in implementing and maintaining rigid dietary exclusion of lactose and galactose;
- Monitor for develomental delays, speech delay, and, in females, ovarian failure;
- For those identified after irreversible consequences, assist in management, particularly with developmental and educational interventions.
Specialty Care Collaboration
Initial consultation and ongoing collaboration, particularly for dietary management. Genetic counseling for the family.Resources
Information & Support
For Professionals
ACT Sheet for Classical Galactosemia (ACMG)
(
348 KB)
Developed by the American College of Medical Genetics (ACMG), includes recommended responses to positive newborn screening
test results, diagnostic evaluation, clinical expectations, and sources of additional information. See the ACMG ACT Sheets
and Confirmatory Algorithms (link elsewhere on this page) for more info and sheets on other conditions.
ACT sheet for Primary or Secondary Hypergalactosemia (ACMG)
( 345 KB)
Developed by the American College of Medical Genetics (ACMG), includes recommended responses to positive newborn screening
test results, diagnostic evaluation, clinical expectations, and sources of additional information. See the ACMG ACT Sheets
and Confirmatory Algorithms (link elsewhere on this page) for more info and sheets on other conditions.
ACT Sheets and Confirmatory Algorithms (ACMG)
The American College of Medical Genetics (ACMG) has developed ACTion (ACT) Sheets and algorithms for responding to positive
newborn screening test results. This page contains a table with links to all of the ACT Sheets and related algorithms.
Galactosemia (GeneReviews)
Excellent review by Louis Elsas, MD including clinical description, differential, management, genetic counseling, molecular
genetics, and a bibliography.
Resources for galactosemia (NLM)
Comprehensive compilation of links to information, articles, research, case studies, genetics, and more; from the National
Library of Medicine and the Genetic Alliance.
Galactosemia (Iowa Dept. of Health)
( 81 KB)
A 3-page overview of galactosemia from the Iowa Dept. of Health's web site.
Galactosemia Newsletter (Utah Newborn Screening Program)
( 16 KB)
Eight pages with details on screening, diagnosis, genetics, and management of galactosemia.
For Parents and Patients
Galactosemia (Genetics Home Reference)
Excellent, detailed review aimed at patients and families from the National Library of Medicine's Genetics Home Reference
site.
Galactosemia.org
Site sponsored by Parents of Galactosemic Children, Inc. (PGC) with information on the condition, special diets, conferences,
and more.
Galactosemia, parent info sheet (Nebraska Newborn Screening Program)
( 28 KB)
Single page information sheet for parents whose child has a positive screening test.
Galactosemia tutorial for parents, English and Spanish
From the Iowa Department of Health's Center for Congenital and Inherited Disorders web site, click the link for "Patient Education
Learning Modules" for several tutuorials on congenital conditions from the Patient Education Institute. Please let us know
if this link disappears or no longer works.
Patient Education
What is Galactosemia? Genetic Science Learning Center - University of Utah
A brief educational overview of the genetics of galactosemia from the Genetic Science Learning Center at the University of
Utah.
Services
Newborn Screening Programs
Utah Newborn Screening Program,
more info...
44 Mario Capecchi Drive
Salt Lake City, UT 84114
Phone: 801-584-8256
Fax: 801-536-0966
http://health.utah.gov/newbornscreening
Pediatric Medical Genetics
See all Pediatric Medical Genetics services providers (3) in our database.
For other services related to this condition, browse our Services categories or search our database.
Helpful Articles
PubMed search for review articles on galactosemia in the last 5 years.
Freer DE, Ficicioglu C, Finegold D.
Newborn screening for galactosemia: a review of 5 years of data and audit of a revised reporting approach.
Clin Chem.
2010;56(3):437-44.
PubMed abstract
Authors
| Author: | Nicola Longo MD, PhD, 3/2007 |
| Compiled and edited by: | Alfred Romeo RN, PhD, 3/2007 |
| Content Last Updated: | 7/2010 |