The Roots of Monogenic Diabetes

A gene is a strand of DNA (deoxyribonucleic acid) – essentially a long “ladder” of nucleotide “letters” that are the code for proteins that do all the work in all the cells of the body. Genes contain information to pass traits from parents to their children.  If a genetic error occurs, it causes a change in the protein sequence – that is, some of the “rungs” get out of order. This is known as a mutation.

The human body has about 30,000 individual genes. So far, more than 20 have been linked to monogenic diabetes. An error in any one of these genes can cause a child or adult to develop monogenic diabetes, and it can be passed on in the family.  Some examples include:

  • MODY, most commonly caused by mutations in the HNF1A gene or the GCK gene
  • Neonatal diabetes, most often caused by a mutation in any one of three genes: KCNJ11, ABCC8 or INS

Scientists do not yet understand exactly why genetic mutations occur. We do know that mutations can be:

  • Spontaneous: occurring during fetal development in a person whose parents do not appear to carry the mutation.  Spontaneous mutations can become hereditary in the next generation.
  • Hereditary: passed from parent to child

Did You Know?

Some forms of monogenic diabetes have symptoms that are moderate or absent, such as MODY caused by a mutation in the GCK gene. Frequently, this condition causes such mild changes in blood sugar levels that it remains unnoticed, and only comes to light during a routine health screening.  With rare exception, GCK-MODY requires no treatment at all.

Other forms of monogenic diabetes have more serious effects on blood sugar levels and will cause long-term complications without treatment. Patients might need frequent insulin injections and other medical interventions.