Parents who have infants affected by the rare forms of CPT deficiency rarely have any warning of impending danger. Stunned by a sudden, life-threatening event or death of an apparently healthy baby, they are left with a deep, life-long loss and a bewildering array of complex medical and genetic questions. Some families lose multiple children before the underlying disorder is identified.

3 forms of CPT deficiency in infants
According to a 1999 review by JP Bonnefont, MD, PhD, a total of 39 babies in 35 families have been reported with the three forms of CPT deficiency that affect infants. In those 35 families, CPT deficiency was also suspected in an additional 26 siblings who died suddenly. Such serial tragedies have spurred American parents to advocate broader mandatory newborn screening. In most states, newborns are routinely screened for only the most common genetic disorders such as phenylketonuria and sickle cell disease.

L-CPT I deficiency and Severe Infantile CPT II deficiency
Early diagnosis would clearly benefit babies with L-CPT I deficiency and the severe infantile form of CPT II deficiency. Crucial in the management of these two disorders is the prevention of Reye-like attacks of hypoketotic hypoglycemia with frequent feedings, intravenous glucose, a diet low in long-chain fatty acids and supplements of medium-chain triglycerides and carnitine. In most cases, the attacks are triggered by fasting or fever. During acute attacks, infants with L-CPT I deficiency always demonstrate an enlarged liver and elevated liver enzymes. However, with treatment these babies do well. Currently all but one of the index cases have reach age four or older, and two are reported to be healthy at age 20. While children with the severe infantile form of CPT II deficiency have not done as well, some have benefited from treatment. Three children with this form of CPT II deficiency are reported to be healthy at 5, 9 and 20 years of age. Heart beat disorders caused sudden death in 6 cases and Reye syndrome led to death in 4 others.

Lethal Neonatal CPT II deficiency
Whether early recognition would benefit babies with the lethal neonatal form of CPT II deficiency is not known. The neonatal form affects many body systems and causes respiratory distress, hypoglycemia, seizures, enlarged liver, enlarged heart, and rhythm and conduction disorders. All infants with this form have died shortly after birth with the exception of one who improved markedly with intravenous glucose and insulin combined with repeated exchange transfusions.

Detection of neonatal carnitine palmitoyltransferase II deficiency by expanded newborn screening with tandem mass spectrometry. Albers S et al. Pediatrics 2001;107(6):E103

Hepatic carnitine palmitoyl transferase I deficiency in North American Hutterites: evidence for a founder effect and results of a pilot study on a DNA-based newborn screening program. Prasad C et al. Mol Genet Metab 2001;73(1):55-63