Galactosemia

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Galactosemia
Body Parts: Whole Body
Medical Subjects: Children's Health Blood Genetic disease
Overview

What Is The Galactosemia?

  • What are galactose and lactose?

Lactose is mainly present in human milk, milk and dairy products. After lactose enters the human body, it can be hydrolyzed into glucose and galactose by the action of various enzymes, and then the galactose is also converted into glucose to provide energy for the body.

  • What is galactosemia?

Galactosemia is a genetic disease, and it is caused by the lack of enzymes related to lactose metabolism in the body due to genetic factors, which affects the normal metabolism of galactose, thus causing the accumulation of galactose in the body, leading to the increase of the level of galactose in blood, i.e., galactosemia.

Excessive galactose can have toxic effects on the body, resulting in various symptoms and complications, such as feeding difficulties, growth retardation, sepsis, cataracts, etc. Seriously ill infants can develop the disease after breastfeeding or milk powder feeding is started after birth.

Galactosemia cannot be cured and requires lifetime avoidance of foods containing lactose or galactose. Through dietary restriction, most children can live safely through childhood, but after puberty, neuropsychological and ovarian problems often occur.

  • What are the types of galactosemia?

According to three different enzyme deficiency, galactosemia can be divided into three categories:

  1. GALT (galactose -1- phosphouridine transferase) deficiency
  2. GALK (galactose kinase) deficiency
  3. UDP GALE (uridine diphosphate galactose -4- epimerase) deficiency

Different types of enzyme deficiency can lead to different clinical manifestations and long-term complications. Galactosemia caused by complete lack of GALT is known as typical galactosemia, and it is the most common and severe type, leading to growth retardation, liver and kidney dysfunction, sepsis, cataract, neurodevelopmental abnormalities, premature ovarian failure, and other problems.

  • Is galactosemia common?

The incidence of galactosemia varies by region and race, but this is uncommon overall. Typical galactosemia occurs in approximately 1 in 60,000 live births.

Cause

What Is The Cause Of Galactosemia?

Galactosemia is an autosomal recessive genetic disease. It can be simply understood that the parents pass the disease-causing gene to their children, causing the children to lack the enzymes related to galactose metabolism in the body, thus causing galactose to be abnormally metabolized and accumulated in the body.

Galactosemia is not contagious, but galactosemia is inherited. In theory, when both husband and wife carry the disease-causing gene, their offspring have a 25% chance of developing galactosemia.

Therefore, prenatal consultation, prenatal diagnosis, and neonatal screening are essential for couples with a family history of galactosemia, or couples who have previously given birth to a child with galactosemia.

Symptom

What Symptom Does Galactosemia Have?

Galactosemia differs in its symptoms and manifestations according to the type.

  • Classic Galactosemia due to total absence of GALT: Symptoms usually occur within days of initiation of breast milk or formula after birth, most commonly with jaundice, vomiting, hepatomegaly, growth retardation, feeding difficulties, lethargy, diarrhea, sepsis, and visual effects associated with cataracts.
  • Galactosemia due to GALK deficiency: Less severe than typical galactosemia, characterized by lens cataracts and, although extremely rare, pseudoencephaloma.
  • Galactosemia due to UDPGLE deficiency: Usually asymptomatic.

What are the serious consequences of galactosemia?

  • Patients with galactosemia may have severe clinical symptoms and consequences, including sepsis, coagulation disorders, neuropsychiatric development disorders, pseudocerebroma, ovarian failure, and others, or may be life-threatening if they are not screened and diagnosed early and corresponding intervention is taken.
Detect

How To Check And Diagnose Galactosemia?

How to diagnose galactosemia?

  • For neonates with typical galactosemia such as jaundice, vomiting, hepatomegaly, growth retardation, feeding difficulty, lethargy, diarrhea, sepsis, and lens cataract, the doctor will suspect galactosemia and further confirm the diagnosis through quantitative determination of red blood cell GALT activity, bacterial inhibition method, DNA mutation analysis, etc.

What tests are needed to diagnose galactosemia?

  • Galactosemia, as an uncommon genetic disease, can be definitely diagnosed only after some special examinations are perfected by a professional institution. The examinations that may need to be performed include:
  • Quantitative determination of red blood cell GALT activity: The results may be affected if red blood cell transfusion from normal donor is received within 3 months.
  • Determination of galactose -1-P concentration in red blood cells: Not affected by red blood cell transfusion, but unable to accurately distinguish complete from partial GALT deficiency.
  • Isoelectric focusing of enzymes.
  • DNA analysis of some hot spot mutations.
  • Bacterial inhibition.
  • Determination of red blood cell GALK/GALE activity, etc.

Which diseases are easily confused with galactosemia? How to distinguish them?

  • Galactosemia is easily confused with other diseases that can cause elevated galactose, such as hepatic dysfunction caused by portosystemic vascular shunt, biliary atresia, and Fanconi-Bickel syndrome, which will lead to elevated blood galactose levels.
  • It can be distinguished according to whether the patient has typical symptoms of galactosemia or not and the results of tests such as quantitative determination of red blood cell GALT/GALK/GALE activity.

Prevention

How To Prevent Galactosemia?

Can galactosemia be prevented? How to prevent galactosemia?

  • As a genetic disease, galactosemia is mainly prevented by prenatal diagnosis. Prenatal diagnosis should be made in couples with a family history of galactosemia or a past history of having children with galactosemia by performing amniotic fluid or chorionic biopsy, culturing the fibroblasts obtained from the biopsy, and performing GALT analysis or DNA mutation analysis to identify genetic defects in the fetus.

How to prevent complications in patients with galactosemia?

  • Screening for galactosemia in neonates facilitates early detection and diagnosis of galactosemia. Once galactosemia is diagnosed, a strict galactose-restricted dietary regimen should be followed, which is effective in alleviating the symptoms and minimizing complications.

What are the complications in patients with galactosemia?

  • However, it is rather helpless that even after dietary treatment is performed, complications such as growth retardation, mental retardation, ovarian failure, and cataract may still occur after entering adolescence.

Treatment

How To Treat Galactosemia?

Which department should patients with galactosemia visit?

  • Galactosemia usually presents with abnormalities within a few days after birth, so presentation to the neonatal department is common.
  • Children who are not in acute phase can have routine reexamination in pediatrics, or go to special genetics department, pediatric internal medicine department and gastroenterology department.
  • Patients with corresponding complications such as cataract and POF should see a doctor in the corresponding department of ophthalmology and gynecology.

Can galactosemia heal itself?

  • No! Galactosemia is an inherited metabolic disease, and strict diet restriction can only alleviate the symptoms, but it cannot be cured, and requires long-term follow-up.

How should galactosemia treat?

  • Treatment varies according to the type of enzyme deficiency, but the most important is nutritional treatment, i.e., controlled diet. For the most common and severe typical galactosemia due to complete lack of GALT, it is necessary to avoid the intake of lactose and galactose from the diet to the greatest extent possible, and to supplement calcium moderately after 1 year old. For specific dietary methods, you can consult a dietician with rich experience in the dietary treatment of hereditary metabolic diseases.
  • For children with jaundice, sepsis, liver and kidney dysfunction and other symptoms and complications, symptomatic and supportive treatment was given according to the specific situation, such as intravenous fluid replacement, administration of antimicrobial agents, improving blood coagulation function, etc. Generally, symptoms resolve quickly after initiation of nutritional therapy. Therefore, the key to treatment still lies in the restriction of galactose intake.

Does galactosemia need regular reexamination?

Yes. Patients with galactosemia should be followed up for a lifetime, such as:

  • Red blood cell galactose -1- phosphate concentrations were monitored periodically to detect whether dietary restrictions were being implemented.

  • Regular assessment of growth and development status, neurodevelopment, ovarian function, eye examinations, etc., in order to detect related complications in a timely manner and take appropriate treatment measures.

Can galactosemia be cured completely?

  • In patients with galactosemia, severe dietary treatment usually leads to effective remission but does not lead to complete cure. Most children with typical galactosemia are healthy in childhood and have normal intelligence. However, after entering adolescence, they often suffer from neuropsychological and ovarian problems, such as delayed development, mental retardation, speech cognitive impairment, ataxia, amenorrhea, and infertility.

Life

What Should Galactosemia Patient Notice In Life?

What should the patient of galactosemia notice on food?

Strict restriction of lactose and galactose intake in patients with galactosemia:

  • For infants, breast-feeding or formula feeding should be discontinued and switched to soy-based formula feeding.
  • Avoid all forms of lactose-containing dairy products, such as butter, cream, cheese, skimmed milk powder, whey, and casein, after starting the supplement.
  • Although free galactose is present in some vegetables and fruits, it is present in an insignificant amount compared to the galactose produced endogenously and in most cases does not require severe restriction.
  • In particular, lactose-free infant formula should not be used as there is no evidence that lactose-free infant formula is safe for children with galactosemia.
  • Children over 1 year old with galactosemia need to be supplemented with calcium according to needs, and the requirements for energy, protein, vitamins, and trace elements are similar to those of normal children, and no additional supplement is required.
  • Because dietary treatment is extremely important and relatively complex for patients with galactosemia, it is recommended to consult a dietician with extensive experience in dietary treatment of hereditary metabolic diseases, and to monitor red blood cell galactose -1- phosphate concentration regularly to assess the effectiveness of dietary treatment.

Does galactosemia affect fertility?

  • Most female patients with typical galactosemia will suffer from primary ovarian dysfunction, which can lead to POF, infrequent or amenorrhea of menstruation, and even infertility. The male patient had normal puberty development and fertility.
  • In addition, couples who have galactosemia themselves or a family history of galactosemia are more likely to have children with galactosemia, so it is recommended to improve the antenatal consultation and necessary prenatal diagnosis and neonatal screening.

Can galactosemia be transported by plane, exercised vigorously and traveled to high altitude?

  • These activities are not recommended in patients with acute galactosemia, especially in combination with severe manifestations such as sepsis. However, the above activities were not affected in patients who were diagnosed as in remission and had effective dietary treatment.

How does galactosemia patient take care of at home?

  • Assist in the development and monitoring of patient adherence to a strict galactose-limited dietary regimen.
  • Accompany the patient to the hospital for follow-up visit regularly.
  • Pay attention to the patient's growth and development, speech cognition, vision, menstruation, psychological state and other aspects of the situation, if there is any abnormal, timely take the patient to see a doctor.

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