2-Methyl-3-Hydroxybutyric Aciduria

What is 2-Methyl-3-Hydroxybutyric Aciduria?

Among rare diseases, 2-Methyl-3-Hydroxybutyric Aciduria is (2M3HBA) is very rare. Only 11 cases have been recorded.
2M3HBA is a genetic disorder that presents itself in infancy or early childhood (usually between 9 and 14 months). Patients with this disorder can’t breakdown the amino acid isoleucine, so the patient’s body develops an overload of isoleucine which affects the body’s ability to regulate some activities of the nervous system.

Boys seem to have more significant developmental issues and can have severe neurodegeneration. They may have difficulty with muscle movement and loss of motor skills. They may also suffer from regression, which is the loss of development milestones before the age of 5.

On the other hand, females tend to have mild to moderate developmental delays and do not face the prospects of regression.

What are the Symptoms of 2-Methyl-3-Hydroxybutyric Aciduria?

2M3HBA symptoms include: metabolic acidosis, low blood sugar, weak muscle tone, seizures & movement problems. Patients my sleep more and experience tiredness and a lack of interest in food. Other symptoms may include:

• Aggressive behavior
• Agitation
• Cerebral cortical atrophy
• Choreoathetosis
• Poor language development
• Difficulty articulating speech
• Hearing loss
• Retinal degneration

What causes 2-Methyl-3-Hydroxybutyric Aciduria?

2M3HBA is caused by mutations in the HSD17B10 gene. An X-linked dominant pattern of inheritance is responsible for spreading the mutation. According to Genetics Home Reference, diseases that have an X-linked dominant pattern have two distinctions: They are more severe in male patients, and fathers cannot pass along their X-linked traits to their sons, so there is no male-to-male transmission.

How is 2-Methyl-3-Hydroxybutyric Aciduria diagnosed?

Diagnosing 2M3HBA is usually made by the healthcare provider after a baby’s symptoms have started or there is a noticeable delay in development. In these cases, the parent has noticed some differences in the child such as they sleeps longer and more often, or they may have noticeable lethargy and / or loss of appetite. Some may even exhibit a weakness to their muscles or suffer from seizures. and reported them to the child’s doctor. They’ll look at a medical history, symptoms, physical exam, and laboratory test results to arrive at a correct diagnosis.

What are the treatments for 2-Methyl-3-Hydroxybutyric Aciduria?

Unfortunately, there are few options for treating 2M3HBA. Eating a well balanced diet, that avoids the proteins and fats that the patient cannot breakdown, is the key. If they do eat those foods that are high in protein and fats, they will likely begin to show symptoms of 2M3HBA.
Proper planning of meal content is not the only important factor. The timing of a patient’s meals is critical as well. Patients with 2M3HBA should not fast, as fasting could trigger the symptoms mentioned above. Patients with 2M3HBA should eat more often to avoid triggering 2M3HBA symptoms.

Where can I find more information about 2-Methyl-3-Hydroxybutyric Aciduria?

• NIH
• Baby’s First Test
• Organic Acidemia Association