Researchers reported the case of a patient diagnosed with carnitine palmitoyltransferase 2 (CPT2) deficiency with a novel mutation and published their findings in Cureus.

For fatty acid oxidation to occur, shuttles are needed to transport long chain fatty acids from the cytosol into the mitochondria. A number of enzymes play a major role in this, including CPT 1 and 2. 

CPT2 deficiency compromises the transport of long chain fatty acids into the mitochondria, impairing oxidation. Hence, CPT2 deficiency falls under the category of long chain fatty acid oxidation disorders. It is inherited in an autosomal recessive manner.


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The case study as described by Alsahlawi and colleagues details a 7-year-old male born with his twin sister to parents with no known genetic diseases. The patient weighed 1.6 kg and his sister weighed 1.7 kg upon delivery. They were admitted to the neonatal intensive care unit for low birth weight. 

Read more about long chain fatty acid oxidation disorder differential diagnosis

At 10 weeks, the patient’s sister became critically ill with tachycardia and hypotension. She was found to be hypoglycemic with cardiomyopathy and demonstrated signs of sepsis. She died on the same day without a specific diagnosis. Because her physicians suspected an inborn error of metabolism, they encouraged her family to investigate her twin brother.

Upon further investigation, the twin brother’s echocardiogram revealed mild left ventricular and septal hypertrophy. His acylcarnitine profile demonstrated very low free carnitine levels, consistent with a diagnosis of systemic carnitine deficiency. The patient was prescribed L-carnitine and medium-chain triglyceride oil with diet modification. 

At 21 months of age, the patient presented with fever, vomiting, and reduced feeding. Laboratory results demonstrated hypoglycemia, leukocytosis, hyperammonemia, high lactate dehydrogenase, and normal creatinine kinase. An analysis of acylcarnitine revealed a high C16 value (10.48) and a high C18:1 value (10.80). Molecular genetic testing of the CPT2 gene revealed the variant c.161T>G (p.ille54Ser) in a homozygous state. This confirmed the diagnosis of CPT2 deficiency. 

“Following confirmation of his diagnosis, our patient did not experience any illnesses requiring admission for four years,” the authors concluded.

Reference

Alsahlawi Z, Fadhul Z, Mahmood A, et al. A case of carnitine palmitoyltransferase II deficiency in Bahrain with a novel mutation. Cureus. 14(6):e26043. doi:10.7759/cureus.26043