When the Brain Is Involved Too

This is a harder subject, and it applies to some children rather than most. It is worth understanding because early treatment appears to matter.

The gate that fails in the commonest form of neonatal diabetes — the KATP channel — is not only found in the pancreas. The same structure exists in muscle and in the connections between brain cells. So certain changes in the KCNJ11 gene can affect all three.

Where that happens, children may have developmental delay, low muscle tone, or epilepsy alongside their diabetes. The most severe combination has a name: DEND, standing for developmental delay, epilepsy and neonatal diabetes.

Severity varies widely — even, sometimes, between children with the same genetic change. Many children with a potassium channel cause have no neurological features at all.

In a long-term study of children with these genes, neurological features were recorded in 47% before they moved onto tablets, and in 64% at the ten-year review — partly because some features only become recognisable as a child grows.

The treatment picture is honest but not bleak. Moving onto sulfonylurea tablets improved neurological features in some children, though the improvement was usually partial rather than complete. Researchers believe treating earlier gives the better chance, because the brain is developing fastest in the first years.

That is the practical conclusion for a parent: this is another reason to press for genetic testing and, where appropriate, transfer as early as possible. If your child does have developmental or seizure difficulties, ask for a paediatric neurology referral and early developmental support.