When people hear the word “diabetes”, they usually think of adults, or perhaps children with type 1 diabetes or teenagers with type 2 diabetes.
Very few imagine that a tiny baby in their first months of life being diagnosed with dangerously high blood sugar.
But it happens.
And when diabetes appears in very young infants, it may not be the usual type 1 diabetes.
It could be something rare, but very important to recognise, called neonatal diabetes.
Emergency at three months
A three-month-old baby was rushed to the hospital with vomit-ing, poor feeding and unusual sleepiness.
His parents were worried.
Over the previous days, they noticed he was soaking through nappies and seemed unsettled all the time.
In the emergency department, doctors discovered his blood sugar was extremely high.
Even more alarming, he was in diabetic ketoacidosis (DKA), a serious condition where the body produces dangerous acids because it cannot use sugar properly.
We usually see DKA in young children newly diagnosed with type 1 diabetes.
But this baby was only three months old.
Stabilising him was delicate work.
Babies are incredibly sensitive to insulin. They need very small doses, which is hard to administer.
It is a tricky balance.
Too much insulin can cause severe low blood sugar, which is especially dangerous for a developing brain.
Too little insulin keeps the blood sugar dangerously high.
Every adjustment had to be precise; every hour required close monitoring.
But one important question remained: Why would a three-month-old develop diabetes?
Consider genetic testing
Here is a key message for parents and healthcare providers: If diabetes is diagnosed before six months of age, it is almost never typical type 1 diabetes.
Type 1 diabetes, which is the most common type of diabetes in children, is an autoimmune disease.
The body’s immune system attacks the insulin-producing cells in the pancreas.
This process is very rare in babies under six months of age.
When diabetes develops this early, we strongly suspect neonatal diabetes, which is a rare genetic condition.
Between six and 12 months of age, type 1 diabetes becomes more likely, but genetic testing should still be considered, especially if
- Diabetes antibodies are negative, and
- The baby is not typical for a type 1 diabetes patient.
In short, always test for genetic causes if the child is under six months of age, and strongly consider testing if the clinical features are unusual for a child six to 12 months old.
Blocking insulin release
Neonatal diabetes is a rare form of diabetes caused by a change (mutation) in a single gene.
That is why it is called monogenic diabetes – “monogenic” meaning “one gene”.
Instead of the immune system destroying insulin cells (as in type 1 diabetes), the problem lies in how the insulin-producing cells function.
It affects approximately one in 90,000 to 160,000 newborns, i.e. it is rare, but not unheard of.
There are two main types of neonatal diabetes:
- Transient neonatal diabetes
Diabetes appears in early infancy, but may disappear within months.
However, it can return later in childhood or adulthood.
- Permanent neonatal diabetes
Diabetes is lifelong, while the treatment depends on the specific genetic cause.
Genetic testing is not just about naming the condition; it can completely change treatment.
In type 1 diabetes, the body cannot produce insulin and lifelong insulin injections are required.
In some forms of neonatal diabetes, the pancreas can produce insulin, but the cells are “switched off” because of a faulty gene.
A specific oral medication can switch the gene back on.
That means some babies can transition from insulin injections to tablets.
This is life-changing.
Without genetic testing, these babies may be misdiagnosed as having type 1 diabetes and remain on insulin for life unnecessarily.
In certain types of neonatal diabetes, the faulty gene causes a potassium channel that controls insulin release from the pancreas to remain open, thus preventing insulin from being released into the blood to reduce blood sugar.
A group of medications called sulphonylureas can close that faulty channel.
Once closed, the pancreas begins releasing insulin more normally.
Instead of injecting insulin from the outside, the body starts making and releasing its own insulin again.
The transformation can be remarkable, resulting in:
- Better glucose stability in the body
- Fewer extreme blood sugar highs and lows
- No more daily injections of insulin, and
- Improved quality of life.
Not all types of neonatal diabetes respond this way, but many do and it can be life-changing.
Baby challenges
Caring for a baby with diabetes is very different from caring for an older child with diabetes, as they:
- Feed frequently and unpredictably, making it hard to match with insulin doses
- Cannot tell you when they feel low
- Have very small insulin requirements
- Have rapidly developing brains vulnerable to glucose swings.
That is why getting the diagnosis right matters so much.
Back to the three-month-old who came into the Emergency Department.
After stabilising him on insulin, we sent some of his blood for genetic testing.
The results showed a mutation known to respond to oral sulphonylureas.
Slowly and carefully, we transitioned him from insulin injections to oral medication.
His glucose levels improved and the wide swings settled.
His parents no longer had to calculate tiny insulin doses, monitor blood glucose intensively or give insulin injections several times a day.
Important messages
It is crucial to remember that diabetes in babies under six months of age is almost never type 1.
Genetic testing should be considered for all babies below one year old with negative pancreatic antibodies.
This is as early diagnosis can completely change a child’s treatment and future, with some forms of neonatal diabetes able to be treated with tablets instead of insulin.
While neonatal diabetes is rare, it is one of the most important diagnoses not to miss.
In a tiny baby fighting DKA, the difference between lifelong insulin and a simple daily tablet may come down to a single gene.
That is the miraculous power of modern medicine.
Dr Jeanne Wong Sze Lyn is a consultant paediatrician and paediatric endocrinologist. For more information, email starhealth@thestar.com.my. The information provided is for educational purposes only and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.
