MCT8-AHDS Foundation

Why are some cases more severe than others?

  • genetic mutation – even though it’s the same gene that’s affected, its mutation is different; and

  • amount of hormones able to pass inside the cells. The most severe cases are the ones in which not even the smallest amount of hormones is able to pass inside the cells.

How can you detect it?

MCT8 Deficiency (AHDS) is hard to diagnose.

The earliest observed abnormalities, at around 2-3 months of age, include floppy body and the inability to support their head.

Typical thyroid tests that may indicate further research in this direction are high serum T3 and borderline low to low T4. Confirmation of the diagnosis requires genetic testing.

Who can diagnose?

Either a Pediatric Neurologist (due to the fact that it involves mental and motor delay) or Pediatric Endocrinologist (due to the fact that thyroid hormone tests abnormalities are characteristic for the syndrome)

The most common indicator is that they cannot support their heads. This is the first milestone that a typical child reaches at the age of 3 months old.

For children with MCT8-AHDS this is something that they will struggle with for the rest of their lives. In time they develop spasticity in the superior and inferior members while the body remains affected by hypotonia.

     

    Symptoms may include:

    1. Lack of head control

    2. Central hypotonia combined in most cases with peripheral hypertonia

    3. Intellectual disability

    4. Inability to gain and maintain weight

    5. Increased heart rate – related to the high blood toxicity.

    6. Motor delay

    7. Low bone density – it is believed to be a symptom associated with high blood toxicity

    8. Epileptic seizures

    9. Delayed myelination

    10. Sleep problems

    11. Problems swallowing/chewing

    12. Dystonia

    13. Spasticity

    14. Low Immune system - Ascorbic acid

     

    N.B. This answer has been created with the help of the online MCT8-AHDS community. Thank you all for sharing your knowledge and experience.