Congenital Hyperinsulinism  

Have you heard of Congenital Hyperinsulinism? Read on to hear Lienke’s story, and the challenges she has overcome.

“My daughter, Lienke was born with a rare congenital disorder called Congenital Hyperinsulinism (CHI). Congenital Hyperinsulinism is a genetic disorder in which the insulin cells of the pancreas, called beta cells, secrete too much insulin, causing low plasma sugar (hypoglycemia) or low blood sugar.

Our journey with Congenital Hyperinsulinism

Lienke was born weighing 4kg and on day 2 she did not want to drink and was very pale. I told the nurses there was something wrong with her but they just said she had her first bath, she will be fine.  She did not want to drink the whole day and I asked them again to check – I knew something was not right.  When they took her blood sugar it was under 1mmol/l and they quickly put her on a glucose drip. 

We got home and and Lienke started having convulsions. It was very scary because we did not know what was wrong. One day she had a big convulsion and we took her to the emergency room at the hospital.  They told us she had epilepsy, but the convulsions continued.

When she was 4 months old, we took her to a paediatric  endocrinologist and she was diagnosed with Congenital Hyperinsulinism. 

Her sugar would fall from 9 to 2mmol/l in 5 minutes and then she would have a convulsion.  When she was 18 months old, she had a pancreatectomy and they removed 80% of her pancreas. 

Daily management challenges

It has been so difficult because Lienke does not like to eat and we constantly have to force feed her to get her sugars up. Kids with CHI usually have no appetite because of too much insulin. So we have had to force feed Lienkie since birth.

Lienke also doesn’t like any sweet stuff, and that is what makes it extra difficult. Since she was a baby, she refused to eat sweets or drink juice.  She likes water and everything that is healthy but she needs to eat 5 times more sugar than other people. This year for the first time she started to eat sweeter stuff like ice-cream and she might drink an apple juice now and then. 

One of the negative side effects of the medication (Diazoxide) used to treat CHI is water retention – it’s not good for your organs like your heart, liver and kidneys.  But the main side effect was hair growth! It does not sound that bad, but it was very bad.  Lienke had hair growing all over her body even on her face… I had to shave off the hair on her face.   

Genetic test

When Lienke was 5 years old, a professor in genetics at the university of Pretoria, Dr Honey, helped us to send our DNA overseas to get tested. It took 6 months for the results to come back. The tests showed:

She tested positive for a likely pathogenic variant in ABCC8.  The inheritance pattern is autosomal dominant, indicating that when Lienke wants children of her own she will have a 50% risk to have an affected child.  The specific gene defect is associated with large babies to persistent hyperinsullinemic hypoglycaemia to early-onset diabetes mellitus in adults.  

What do you wish you’d know when Lienke was born?

I really wish they had diagnosed her at birth with CHI, then we would know not to let her go without food for more than an hour and we would have know what caused the convulsions, and monitored her very closely.  

How did you know to go to a paediatric endocrinologist?

A friend’s child also had convulsions when her blood sugar was low. After that, we realised that when she hadn’t eaten a lot she had a convulsion, so we went to see a paediatric endocrinologist.

How often does her blood sugar drop so suddenly?

Before her pancreatectomy her sugar would drop any time – sometimes after 30 minutes, sometimes an hour, we never could predict it.  We also did not have a CGM to measure her blood sugar. We had to prick her finger to test, and couldn’t do it every 10 minutes.  Because she ate so little it was very difficult to predict. We never slept and when she did not want to drink milk we had to use a syringe to put milk in her mouth.

How often does she have to eat? 

Before the pancreatectomy, she had to eat every 30 minutes and at night every 2 hours. But after the pancreatectomy it was better – during the day every hour and at night every 5 hours.  At the moment, because she can eat more, she can eat every 2 hours during the day and at night if she eats for the last time at 9pm it will last her till 7 or 8am in the morning. When she was 5 years old, she got a feeding tube for when her blood sugar is low and she doesn’t want to eat – we can put glucose in her tube. It’s been a very tough few years but we are managing.  

Have you found anything that is particularly helpful or supportive?

The Dexcom CGM device is very helpful, it helped us a lot, but it’s very expensive.  She went to grade R this year and we put it on for her for 2 weeks just to see how her sugar is doing with the new school, new teachers, new times and it helped a lot but we can’t afford it full time.  We like the Dexcom because it will tell me when her sugars are low if I’m at work and I can let the teacher know.  Even at night.  We used the FreeStyle Libre sensors a lot when she was small, but with her going to school the Dexcom works better. 

The other thing that helped is community. We are on an international Congenital Hyperinsulinism group where parents all over the world share their stories, ask questions and support each other. I must say this helped a lot. The other day Lienke came from school and our nanny took her sugar and it was 3.2mmol/l, but Lienke had no symptoms of low blood sugar – her body is so used to low sugars it’s sometimes difficult to see if she has a low.  And that makes it dangerous because it’s still not good for her.  

What would you say to other parents of children with Congenital Hyperinsulinism? 

I would say just hang in there, it gets better, we are a small group of parents in South Africa that have kids with CHI and we try to support each other on a WhatsApp group. If they start to understand they have to eat to feel better, it gets easier.”

We think Lienke is lucky to have such wonderful parents!

What to read next?

What is a CGM? Flash glucose monitoring and CGM: sensor that is inserted into your body (usually your stomach, upper arm or thigh) that takes constant blood sugar readings throughout the day.

Your options on the Discovery CGM Benefit: There are 3 CGM / flash glucose monitors available in South Africa. Here’s what they are, and how much they cost.

The Type 1 Diabetes Guidebook – for parents: The guidebook includes everything from an explanation of what diabetes is to what affects blood sugar, how to cope with a Type 1 diabetes diagnosis and essential information for family, friends and caregivers.