What Is Rabson-Mendenhall Syndrome?

Medically Reviewed by Murtaza Cassoobhoy, MD on May 28, 2023
Written by WebMD Editorial Contributors
3 min read

One of the most basic things your body does is get energy from your food and deliver it to your cells. It’s a lot like gassing up your car, but in this case, sugar provides the energy. Usually, a hormone called insulin controls the process. It tells the sugar when to move out of your blood and into your cells.

If you have Rabson-Mendenhall syndrome, this process breaks down. Your body can’t use insulin like it needs to. It’s a very rare condition.

When insulin can’t do its job, it impacts how your body grows. And the effects start even before birth. Babies who have it tend to be smaller than usual and struggle to grow and gain weight.

Rabson-Mendenhall syndrome is part a group of conditions that doctors call severe insulin resistance syndromes. These include Donohue syndrome and type A insulin resistance syndrome.

Rabson-Mendenhal is a condition you get from your parents, and it happens because of a glitch in a gene called the INSR gene.

Each of your cells has two copies of every gene. One copy comes from your mother and one from your father. When you have Rabson-Mendenhall, it means you have the glitch in both copies of the INSR gene. If only one copy has it, you won’t have the condition.

So when a child gets Rabson-Mendenhall syndrome, it’s because each parent had one copy that was normal and one that had the glitch. Then, they both happened to pass the copy with the glitch onto the child, and 3 out of 4 times that doesn’t happen.

Signs and symptoms may start to show in the first year of life and are more severe in some people than in others.

It can cause problems with your:

  • Head and face. These can include rough skin, wide space between the eyes, deep grooves in the tongue, and larger-than-normal ears, lips, and jaw.
  • Nails. They may be thicker than usual.
  • Skin. Dryness is one problem. Another might be acanthosis nigricans (skin that darkens and thickens). It may feel like velvet, especially in areas where it folds, like the underarms and neck.
  • Teeth. They can be larger than normal, crowded, or come in too early.

Other common signs and symptoms include:

  • Larger organs than normal, including the kidney, heart, penis, and clitoris
  • Much more hair than is typical
  • Slow growth before and after birth
  • Swelling in the belly
  • Very little fat under the skin
  • Weak muscles

And it can lead to conditions such as:

One of the challenges in telling whether someone has Rabson-Mendenhall is making sure it’s not a similar condition, such as Donohue syndrome. Your child’s doctor will do a physical exam and ask about their symptoms and health history. They’ll probably want to get blood tests to check on your child’s blood sugar and insulin levels.

Treating Rabson-Mendenhall usually requires a team of doctors, surgeons, dentists, and others. Your family may also want to seek counseling to work through the emotions of having a rare disease.

Since there’s no cure, treatment often focuses on specific symptoms, such as surgery to remove cysts or fix dental problems. Sometimes, doctors use high doses of insulin or certain drugs that help the body use insulin, but often these don’t work for very long.

Experts are looking for better treatment options for hyperglycemia (high blood sugar) linked to severe insulin resistance. These treatments have shown some good results so far, though more research is needed:

  • Biguanides. These are medicines that cause your body to make less glucose (sugar) and boost its use of insulin.
  • Leptin. This protein may help with blood sugar and blood insulin levels.
  • Recombinant insulin-like growth factor I (rhIGF-I). This protein treats ketoacidosis that is caused by severe insulin resistance. Ketoacidosis is the buildup of ketones – a substance that forms when the body breaks down fat for energy instead of sugar.