🧬 Gene Summary: HK1
Also called Hexokinase 1, a key enzyme in glucose metabolism
What does the HK1 gene do?
The HK1 gene provides instructions to make an enzyme called hexokinase 1, which helps the body sense and use sugar (glucose). In the pancreas, this gene is usually turned off.
How can changes in HK1 cause hyperinsulinism?
People with HK1-hyperinsulinism have genetic changes in the gene which cause the gene to be inappropriately switched on in the pancreas. This causes the pancreas release too much insulin, even when blood sugar is low, leading to repeated episodes of low blood sugar (hypoglycemia).
How common are changes in HK1 in hyperinsulinism?
Non-coding HK1 variants are a rare but recognized cause of congenital hyperinsulinism.
How are changes in HK1 inherited?
HK1 genetic changes can be inherited in different ways:
• Dominant inheritance
o One non-working copy of the gene or regulatory region may be enough to affect insulin release
o A parent may have mild symptoms or none at all
• New (de novo) changes
o Sometimes the gene change happens for the first time in the child
💡 A genetic counsellor can explain what this means for your family and future children.
What does an HK1 change mean for my child?
Children with HK1-related hyperinsulinism may:
• Have low blood sugar starting shortly after birth
• Need frequent feeds, medication, or IV glucose
• Have symptoms that range from mild to severe
Some children improve over time, while others may need longer-term treatment.
Does knowing about an HK1 change affect treatment?
Yes — knowing that a child has an HK1 gene change can help doctors:
• Decide on the best monitoring plan for blood sugar
• Understand how likely standard treatments like diazoxide will work
What about future children or family members?
Genetic testing can:
• Help estimate the chance of hyperinsulinism in future pregnancies
• Identify family members who may carry the gene change
• Guide family planning decisions
Your care team or genetic counsellor can help explain testing options.
Where can I learn more or get support?
• Talk with your child’s hyperinsulinism care team
• Meet with a genetic counsellor
• Connect with hyperinsulinism family support organizations