Researchers presented the case of a baby born at term with multiorgan dysfunction, severe metabolic acidosis, and hyperkalemia.
The baby was later diagnosed with neonatal carnitine palmitoyltransferase type 2 (CPT2) deficiency, a form of long chain fatty acid oxidation disorder (LCFAOD), and succumbed to death a few days later.
“The neonatal form of [CPT2] deficiency is lethal and can present in the first days after birth, usually with multiorgan dysfunction and refractory metabolic acidosis,” the researchers wrote in an article they published in Neoreviews. “Fatty acid oxidation defects should be considered in cases of refractory nonketotic hypoglycemia with metabolic acidosis.”
Within the first 24 hours from birth, the baby presented with respiratory failure and lethargy and needed cardiopulmonary resuscitation. She also had hypoglycemia, hyperkalemia, third-degree heart block, and metabolic acidosis. Later she was found to have heart arrhythmias, biventricular dysfunction, pulmonary hypertension, systemic refractory hypotension, liver failure, dysplastic kidneys, Dandy-Walker malformation, and seizures.
She was diagnosed with CPT2 deficiency based on high levels of C16, C16-OH, and 17-hydroxyprogesterone during a newborn screen, markedly elevated C16 and C18:1, low acetyl signal, low free carnitine, and high C2. The diagnosis was confirmed with mutation analysis of the CPT2 gene, which revealed 2 disease-causing allelic mutations.
Read more about the differential diagnosis of LCFAOD
Cases of abnormal results for CPT2 deficiency during newborn screening warrant further testing with acylcarnitine profile and mutation analysis, the researchers said.
The patient was discharged from the hospital with on nasal cannula, nasogastric feeds, and phenobarbital with home hospice support. She had worsening hepatomegaly leading to abdominal distention and lethargy. She received a “do not resuscitate” status and died at home with hospice support.
Neonatal CPT2 deficiency is the most severe form of CPT2 deficiency. It presents immediately at birth or within 4 days but may also present before birth. Common symptoms include dysmorphic features, cystic renal dysplasia, neuronal migration defects, respiratory distress, hypoglycemia with seizures, hepatomegaly, and cardiomegaly with rhythm and conduction disorders.
Monangi N, Shah M, Cortezzo DE. A term neonate with multiorgan dysfunction, severe metabolic acidosis, and hyperkalemia. Neoreviews. 2022;23(6):e409-e412. doi:10.1542/neo.23-6-e409