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Molecular and Human Genetics

Houston, Texas

Department of Molecular and Human Genetics
Department of Molecular and Human Genetics
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Carnitine and Autism

Can carnitine supplementation in infancy prevent some forms of autism including in infant siblings of autism children or reverse early symptoms of autism?

We do not claim any proven benefits from carnitine supplementation, but our goal is to carry out research to answer these questions and we need your help

We have discovered a new genetic condition caused by TMLHE gene deficiency (PMID: 22566635/doi: 10.1073/pnas.1120210109). The TMLHE gene is essential to make carnitine in the body. Most carnitine comes from the diet, but carnitine can also be made in the body. Carnitine content is low in fruits, cereals, and vegetables; medium in chicken, fish, eggs, and milk; and high in red meats. The TMLHE gene is on the X chromosome so TMLHE deficiency is much more common in boys compared to girls. TMLHE deficiency is found in about 1 in 350 adult males. TMLHE deficiency appears to be a risk factor for autism and could be treated with carnitine supplements, but we need to confirm these results to be sure. This discovery has led us to propose that carnitine deficiency in the brain (neuronal carnitine deficiency; NCD) might cause a preventable form of autism (PMID: 23087240/doi: 10.1126/science.1229178). We seek to test the idea that carnitine deficiency in the brain is a risk factor for autism that is not associated with birth defects or unusual facial features.

Who is eligible?

In order to test our theory, we wish to measure carnitine levels in the blood of infants with autism or infants at increased risk of autism. In order to maximize the efficiency of this study, we are collecting samples from boys between the ages of 9 and 30 months when the parents or doctor are concerned that a boy may be showing signs of autism. We are also enrolling boys who have an older brother with autism regardless of whether the younger boy has any signs or symptoms of autism or not.

Possible outcomes:

  1. The child has TMLHE deficiency. Regardless of the level of carnitine in blood/plasma, the family will be offered further medical evaluation and the opportunity to participate a research study evaluating the potential benefit of carnitine supplementation in the prevention or reversal of autism.
  2. There is no TMLHE deficiency, but the level of carnitine in the blood/plasma is clearly below the normal range. The family will be offered further medical evaluation and the opportunity to participate a research study evaluating the potential benefit of carnitine supplementation in the prevention or reversal of autism.
  3. There is no TMLHE deficiency, and level of carnitine in the blood/plasma is borderline low but not definitely abnormal. No further studies will be recommended, but we will be available to advise families. Parents could decide to offer a beef containing meal a few times a week.
  4. There is no TMLHE deficiency, and the level of carnitine in the blood/plasma is completely in the normal range. No action is indicated.

How to participate:

  1. To learn more, interested families can send an e-mail to carnitine.autism@bcm.edu and provide a telephone number and a time at which it would be convenient to talk with a research coordinator about the possibility of your child taking part in the research. Alternatively you can leave a phone message for Dianne Dang at 713-798-4795.
  2. If your child meets the eligibility conditions, we will provide you with an informed consent explaining the study. If you agree, we will work with you to make arrangements to have a small amount of blood drawn and shipped to our laboratory. Ideally blood is drawn from a vein, but dried blood spots from a finger stick can be used if necessary. After testing, you will receive results as described under Possible outcomes above.
  3. Females, males with birth defects or unusual facial features features, and males above age 30 months will not be eligible to participate in this study. If your child is not eligible to participate, your doctor can order a blood test to measure carnitine in blood and tell you if the level is in the normal range or is low.

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