Carnitine is a naturally occurring amino acid derivative. Serum Carnitine Deficiency (SCD) incidence is 1:37,000 newborns. Carnitine plays an essential role in the transfer of long-chain fatty acids into the mitochondria for beta-oxidation. Age at presentation of SCD is usually ranging from 1 month to 7 years, but cases can occur earlier or later (you have to keep it in your differential). Pathologic effects SCD include (1) the cardiac muscle, which is affected by progressive cardiomyopathy (by far, the most common form of presentation with possibility of sudden death), (2) the central nervous system, which is affected by encephalopathy caused by hypoketotic hypoglycemia, and (3) the skeletal muscle, which is affected by myopathy.
Clinical conditions which you should ask for measurement of serum blood Carnitine:
Neonatolgy and pediatrics: Failure to thrive; Newborn receiving total parentral nutrition; Developmental delay, Recurrent infections, Hypotonic children.
Hematology: Unexplained hypochromic microcytic anemia
Neurology: Encephalopathy (with non-ketotic hypoglycemia and hyperammonia), Unexplained peripheral neuropathy, Abnormal movement, Unexplained myopathy, Abnormal fatigability, epileptic patients taking Valproic acid
Hepatology: Unexplained hepatomegaly in children
Gastroenterology: Patient with gastrointestinal dysmotility
Opathalmology: Pigmented retintopathy
Lab studies: Check serum Carnitine when you have clinical abnormality (as listed above) plus abnormal lab results: e.g.: hypoglycemia without ketones in urine, hyperammonia, increased serum lactate, unexplained increased liver enzymes, increased CPK or unexplained high uric acid in young patients.
Treatment: Carnitine supplement may prove to be life saving.
Summary: Suspect serum Carnitine deficiency (SCD) in any cases with above clinical presentation. Treatment is life saving in these disorders.
In our effort to bring the best of clinical tests to medical practice in Jordan, we would like to announce that this test is available now in Jordan in our lab only.
Please contact us for any further inquiries.
Dr. Hussam Abu-Farsakh
American Boards of Anatomic and Clinical pathology and Cytopathology