Features of carnitine palmitoyltransferase type I deficiency

Abstract

Carnitine palmitoyltransferase type I (CPT I) is unique among long-chain fatty acid oxidation enzymes in that there are two tissue-specific isoforms, 'hepatic' and 'muscle', which are encoded by two separate genes. The 'hepatic' isoform is expressed in liver, kidney and fibroblasts and at low levels in the heart, while the other isoform occurs in skeletal muscle and is the predominant form in heart. Reported patients with CPT I deficiency lack activity of the hepatic isoform and present before 30 months of age with hypoketotic hypoglycaemia, hepatomegaly with raised transaminases, seizures and coma. We discuss four new cases in three families showing, variously, renal tubular acidosis, transient hyperlipidaemia and, paradoxically, myopathy with elevated creatinine kinase or cardiac involvement in the neonatal period as additional features that deserve wider recognition.

Carnitine palmitoyl transferase 1A deficiency in an adult with recurrent severe steato hepatitis aggravated by high pathologic or physiologic demands: A roller-coaster for internists

“…Between episodes of metabolic decompensation, individuals appear normal and long-term liver damage as a result of recurring hepatosteatosis has not been reported. Unlike other long-chain FAODs, cardiac or skeletal muscle involvement in CPT1A deficiency is uncommon as there is a separate isoform of CPT1A, CPTIB, in these organs [12]. Our patient developed severe progressive steato hepatitis at 28 years old concurrent with acute pancreatitis and was partially improved.…”

Newborn Screening for Mitochondrial Carnitine-Acylcarnitine Cycle Disorders in Zhejiang Province, China

“…CPT1D can be triggered by fasting or illnesses and presented with hypoketotic hypoglycaemic episodes and hepatomegaly in the early period of life; few cases may die in neonatal period ( Baruteau et al, 2014 ; Fohner et al, 2017 ). Several cases with mild cardiomegaly, heartbeat disorders, or distal renal tubular acidosis have been reported ( Olpin et al, 2001 ; Yu et al, 2021 ). Most patients with CPT1D had no clinic symptoms and only one case presented with hyperammonaemia and metabolic acidosis and died in the early neonatal period.…”

Study of Carnitine/Acylcarnitine and Amino Acid Profile in Children and Adults With Acute Liver Failure

“…Hyperlipidemia with raised triglycerides and/or cholesterol have also been described as a unique feature of CPT1 deficiency (23,37). In the 2 patients where serum lipid profile was available, there was evidence of definite dyslipidemia-high triglycerides (normal <150 mg/dL) and high very low-density lipoprotein (normal <35 mg/dL) in both, high cholesterol (normal <200 mg/dL) in patient 2 and low high-density lipoprotein (normal >40 mg/dL) in patient 1 (Table 1).…”