Glutaric aciduria type 1 (GA1) is a rare and can be a serious inherited condition if not treated early. It means the body can't process certain amino acids ("building blocks" of protein), causing a harmful build-up of substances in the blood and urine.
Normally, our bodies break down protein foods like meat and fish into amino acids. Any amino acids that aren't needed are usually broken down and removed from the body.
Babies with GA1 are unable to break down the amino acids lysine, hydroxylysine and tryptophan.
Normally, these amino acids are broken down into a substance called glutaric acid, which is then converted into energy. Babies with GA1 do not have the enzyme that breaks down glutaric acid, leading to a harmfully high level of this and other substances in the body.
📊 Prevalence
Worldwide: About 1 in 100,000 live births.
Higher rates in certain populations due to founder effects (where a mutation is more common in a small or isolated population). For example:
Old Order Amish (USA): Much more common—up to 1 in 300.
Ojibwe-Cree tribes (Canada): Higher prevalence noted.
Swedish population: Elevated rates in parts of Sweden.
Worldwide: About 1 in 100,000 live births.
Higher rates in certain populations due to founder effects (where a mutation is more common in a small or isolated population). For example:
Old Order Amish (USA): Much more common—up to 1 in 300.
Ojibwe-Cree tribes (Canada): Higher prevalence noted.
Swedish population: Elevated rates in parts of Sweden.
🧬 Why It's Rare
GA-1 is an autosomal recessive disorder, meaning:
A baby must inherit two defective copies of the GCDH gene (one from each parent).
Carriers (with one copy) typically show no symptoms.
This rarity results from the low likelihood that both parents are carriers of the same rare mutation.
Diagnosing GA1
At around 5 days old, babies are now offered newborn blood spot screening to check if they have GA1. This involves pricking your baby's heel to collect drops of blood to test.
If GA1 is diagnosed, treatment can be given straight away to reduce the risk of serious complications.
With early diagnosis and the correct treatment, the majority of children with GA1 are able to live normal, healthy lives. However, treatment for GA1 must be continued for life.
Without treatment, severe and life-threatening symptoms can develop, including seizures (fits) or falling into a coma. Some children with untreated GA1 are also at risk of brain damage, which can affect muscle movement. This may lead to problems with walking, talking and swallowing.
Symptoms of GA1
Symptoms of GA1 usually don't appear until a few months after birth, although some babies are born with a larger-than-average head (macrocephaly).
Children with GA1 may develop some floppiness or weakness in their muscles (hypotonia) during their first year and there's a risk of developing bleeding around their brain (subdural haematoma). In rarer cases, bleeding can develop around the back of the eyes (retinal haemorrhage).
Metabolic crisis
Children with GA1 may have episodes known as a metabolic crisis, sometimes early in their life. Symptoms of a metabolic crisis include:
- poor feeding or loss of appetite
- lack of energy
- abnormal movements
- vomiting
- irritability
- breathing difficulties
It's important to get medical help immediately if your baby develops symptoms of a metabolic crisis. Your doctor will give you advice to help recognise the signs.
In some cases, a metabolic crisis may be triggered later in childhood by an infection or illness. The hospital should provide you with emergency treatment instructions to follow if your child is ill, which helps to prevent these symptoms developing.
Treating GA1
Diet
Children diagnosed with GA1 are referred to a specialist metabolic dietitian and given a low-protein diet. This is tailored to reduce the amount of amino acids your baby receives, especially lysine and tryptophan.
High-protein foods need to be limited, including:
- meat
- fish
- cheese
- eggs
- pulses
- nuts
Your dietitian will provide detailed advice and guidance, as your baby still needs some of these foods for healthy growth and development.
Breastfeeding and baby milk also need to be monitored and measured, as advised by your dietitian. Regular baby milk contains the amino acids that need to be restricted, so a special formula is used instead. This contains all the vitamins, minerals and other amino acids your baby needs.
People with GA1 may need to follow a restricted protein diet for the rest of their life to reduce their risk of a metabolic crisis. As your child gets older, they'll need to learn how to control their diet and stay in contact with a dietitian for advice and monitoring.
Medication
Your child will be prescribed a medication called L-carnitine, which helps to clear some of the excess glutaric acid.
L-carnitine is given as a tablet and needs to be taken regularly, as directed by your doctor.
Emergency treatment
If your baby develops an infection, such as a high temperature or cold, their risk of having a metabolic crisis increases. It's possible to reduce the risk by changing to an emergency diet while they're ill.
Your dietitian will provide detailed instructions, but the aim is to replace milk and food containing protein with special high-sugar drinks. Medication should still be taken as normal.
Your dietitian may provide you with a feeding tube (nasogastric tube) and show you how to use it safely. This can be useful in an emergency if your baby isn't feeding well while they are ill.
Here's a summary for Easy Reading:
GA-1 is a rare inherited condition that affects how a baby’s body breaks down certain proteins found in food. When someone has GA-1, their body cannot properly handle parts of the food they eat — especially proteins from things like meat, eggs, and dairy.
Instead of being broken down normally, harmful substances build up in the body and can damage the brain, especially if the child becomes sick or doesn’t eat for a while.
🧬 How Do Babies Get GA-1?
GA-1 is something a baby is born with — it’s not caused by anything the parents did during pregnancy.
We all have two copies of every gene: one from our mom and one from our dad.
For a baby to have GA-1, both parents must be “carriers” of a gene that doesn’t work properly.
Carriers are healthy — they don’t have the disease, and most never know they carry the gene.
If both parents are carriers:
There’s a 1 in 4 chance (25%) the baby will have GA-1.
A 1 in 2 chance (50%) the baby will be a carrier like the parents.
A 1 in 4 chance (25%) the baby will be completely free of the gene.
🧪 What Happens in the Baby’s Body?
Think of the body like a kitchen where food is broken down into useful ingredients. A baby with GA-1 is missing a special "tool" (called an enzyme) that helps break down certain parts of protein.
Without this tool:
Toxic substances build up — especially glutaric acid — and these can hurt the brain over time.
This can lead to movement problems, developmental delays, and sometimes seizures.
🩺 How Is GA-1 Found and Treated?
Many places now screen newborns for GA-1 using a simple heel-prick blood test. This helps catch the condition before any damage is done.
If caught early, doctors can prevent problems with:
A special diet low in certain proteins
Supplements, like carnitine, that help the body remove toxins
Emergency care during illness (like flu or fever) to avoid a crisis
With early treatment, many children with GA-1 live healthy lives.
🧪 Molecular Mechanism of Disease
Gene Involved:
The GCDH gene is located on chromosome 19p13.2.
It encodes the glutaryl-CoA dehydrogenase enzyme, which is needed to break down certain amino acids: lysine, hydroxylysine, and tryptophan.
Enzyme Deficiency:
Mutations in GCDH reduce or eliminate the activity of glutaryl-CoA dehydrogenase.
Without this enzyme, the body cannot properly metabolize lysine and tryptophan.
Toxic Build-Up:
As a result, intermediate compounds like glutaric acid and 3-hydroxyglutaric acid accumulate in the body, especially in the brain.
This build-up causes damage to basal ganglia, leading to:
Movement disorders (e.g., dystonia)
Seizures
Developmental delays
❤️ Final Thoughts
GA-1 is not anyone’s fault.
It’s a genetic condition passed down silently for generations.
Early detection and proper care make a huge difference.
For Details visit: https://www.newbornscreening.info/ga-1-glutaric-acidemia-type-1/
Meanwhile, I treated Grandson Ian, wife Sara and Daughter Dinah for a Mexican lunch at the Mezcal Grill on 57th and Broadway, Sacramento. Dinah and I had the Chile Relleno that we consumed with delight and Ian and Sara had the SeaFood Fajitas, Tacos and Beer. While we are eating lunch great grandson Graham is enjoying his nap. Here are four photos of my visit.
From the Restaurant Website: Here at Mezcal Grill, we take pride in bringing the vibrant and mouthwatering flavors of authentic Mexican cuisine to your table. Our menu features a delightful array of traditional dishes that honor the rich culinary heritage of Mexico. But we also believe in the beauty of culinary fusion, so we infuse a hint of Tex-Mex and Californian influences into some of our signature creations. This adds a unique and exciting twist to our offerings, ensuring a dining experience that is both familiar and refreshingly innovative.From sizzling fajitas to irresistible street tacos, from zesty salsas to creamy guacamole, every dish is crafted with care and expertise. Whether you're craving the comforting warmth of a classic Mexican dish or the bold, adventurous flavors of a modern creation, we've got something to tantalize your taste buds.
Grandson Ian King and Great Grandson, Graham King ( One-month old)