Improvement of regressive autism symptoms in a child with TMLHE deficiency following carnitine supplementation.
Disorders of carnitine biosynthesis have recently been associated with neurodevelopmental syndromes such as autism spectrum disorder (ASD). A 4-year-old male with autism and two episodes of neurodevelopmental regression was identified to have a mutation in the TMLHE gene, which encodes the first enzyme in the carnitine biosynthesis pathway, and concurrent carnitine deficiency. Following carnitine supplementation, the patient's regression ended, and the boy started gaining developmental milestones. This case report suggests that deficits in carnitine biosynthesis may be responsible for some cases of regression in individuals with ASD, and that testing for the respective biochemical pathway should be considered. Furthermore, this case suggests that carnitine supplementation may be useful in treating (and potentially preventing) regressive episodes in patients with carnitine deficiency. Further work to better define the role of disorders of carnitine biosynthesis in autism spectrum disorder is warranted.
Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas.
Mark N
MN
Ziats
Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.
Mathew S
MS
Comeaux
Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.
Yaping
Y
Yang
Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.|Texas Children's Hospital, Houston, Texas.
Fernando
F
Scaglia
Texas Children's Hospital, Houston, Texas.
Sarah H
SH
Elsea
Texas Children's Hospital, Houston, Texas.
Qin
Q
Sun
Texas Children's Hospital, Houston, Texas.
Arthur L
AL
Beaudet
Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas.|Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas.
Christian P
CP
Schaaf
D000067877:Autism Spectrum Disorder / Q000235:genetics*; D001321:Autistic Disorder / Q000235:genetics*; D009202:Cardiomyopathies / Q000235:genetics*; D002331:Carnitine / Q000172:deficiency* / Q000235:genetics; D002659:Child Development Disorders, Pervasive / Q000235:genetics; D002675:Child, Preschool; D019587:Dietary Supplements; D006801:Humans; D022124:Hyperammonemia / Q000235:genetics*; D008297:Male; D009135:Muscular Diseases / Q000235:genetics*
D002331:Carnitine
TMLHE; autism spectrum disorder; carnitine; developmental delay; regression