Disease-associated variants of either subunit of KATP, KCNJ11 and ABCC8, can result in a channel that is "stuck open", rendering the β cell unable to secrete insulin in response to high blood glucose. Children born with disease-associated KATP variants often have intrauterine growth restriction and resulting low birthweight. Similarly, the second most common cause of permanent neonatal diabetes is alterations to the gene that encodes insulin. Mutations associated with neonatal diabetes tend to cause misfolding of the insulin protein; misfolded insulin accumulates in the endoplasmic reticulum (ER), leading to ER stress and β-cell death.Most transient neonatal diabetes is caused by the over-expression of a cluster of genes on chromosome 6, a region called 6q24. Over-expression of 6q24 is often caused by anomylous epigenetic regulation of the locus. The copy of 6q24 inherited from ones father normally has much higher gene expression than the copy inherited from ones mother. Therefore, inheriting two copies of the gene region from ones father (either through uniparental disomy, or receiving two copies from ones father in addition to the copy from ones mother) commonly results in over-expression of the locus. Alternatively, inheriting a maternal copy of 6q24 with defective DNA methylation can result in similar over-expression of the locus.Variants in several other genes can cause neonatal diabetes, though these cases are much rarer. Genetic changes that disable the transcription factors CNOT1, GATA4, GATA6, PDX1, PTF1A, or RFX6 – all involved in the development of the pancreas – result in a shrunken or missing pancreas.
The previously listed genetic mechanisms result in twice the normal amount of these two genes and cause chromosome 6q24 TNDM. ZFP57 Gene
Third, mothers hypomethylation defects (a genetic defect that stops the allele from getting  a methyl group, which would inhibit transcription) can occur from an isolated genomic imprinting or occur as a defect called, "hypomethylation imprinted loci" (HIL). HIL is defined as the loss of a methyl group in the 5-methylcytosine nucleotide at a fixed position on a chromosome. Homozygous ( having two of the same alleles) or heterozygous (defined as having one each of two different alleles) ZFP57 pathogenic variant make up almost half of TNDM-HIL, but the other causes of HIL are unknown.Moreover, half of TNDM patients that contain chromosome 6q24-related TNDM experiencing re-occurrence of diabetes during their childhood or young adulthood. The onset of insulin resistance and increased insulin requirements are associated with puberty and pregnancy initiating the relapse of diabetes. In the event of remission, individuals do not show symptoms or impairment Beta-cell function in the fasting state. Insulin secretory response to intravenous glucose loading might be abnormal in those destined to have a relapse of diabetes. TNDM caused by 6q24 genomic defects are always associated with IGUR. Other contributing factors are umbilical hernia and enlarged tongue, which are present in 9 and 30% of patients with chromosome 6q24 related TNDM. Diagnosis
Diagnosis of neonatal diabetes is complicated by the fact that hyperglycemia is common in neonates – particularly in preterm infants, 25–75% of whom have hyperglycemia.