lethal neonatal CPT deficiency type 2

Autosomal recessive metabolic disease.

Synopsis

 craniofacial anomalies

• Microcephaly
• High, sloping forehead
• Prominent forehead
• Cararacts
• Overfolded helices
• Low-set ears
• Posteriorly-rotated ears
• Bulbous nose
• High-arched palate
• Narrow palate

 cardiovascular anomalies

• Cardiomegaly
• Dilated cardiomyopathy
• Thickened myocardium
• Arrhythmias
• Sudden death within first days of life
• Lipid accumulation in heart

 Respiratory distress
 Apnea
 Respiratory failure
 Widely spaced nipples

 heapatic anomalies

• Hepatomegaly
• Macrovesicular steatosis
• Lipid accumulation in hepatocytes
• Liver calcifications

 Gastrointestinal anomalies

• Poor feeding

 urinary anomalies

• Enlarged polycystic kidneys (detectable prenatally)
• Dysplastic renal parenchyma
• Hydronephrosis
• Lipid accumulation in kidney, especially in proximal convoluted tubules
• Renal insufficiency
• Double ureters

 limb anomalies

• Contractures of knees
• Contractures of elbows
• Long, tapering fingers
• Extra digital creases in digits 2-4
• Long, tapering toes
• Hypoplastic toenails

 Lipid accumulation in skeletal muscle

 cerebrospinal anomalies

• Neonatal hypotonia
• Lethargy
• Seizures
• Ventriculomegaly
• Intracerebral periventricular calcifications
• Antenatal intracerebral hemorrhage
• Dysplastic or absent corpus callosum
• Polymicrogyria
• Neuronal migration disorder
• Paraventricular cysts
• Basal ganglia cysts

 Oligohydramnios in some cases

Biology

 Nonketotic hypoglycemia
 Increased liver function tests
 Increased plasma long-chain acylcarnitines
 Increased tissue long-chain acylcarnitines
 Decreased plasma total and free carnitine
 Decreased tissue total and free carnitine
 Increased serum long-chain fatty acids
 Increased tissue long-chain fatty acids
 Long-chain dicarboxylic aciduria
 Hyperammonemia
 Increased total bilirubin
 Increased tissue levels of triglycerides
 Increased tissue levels of free fatty acids
 Severely decreased palmitate oxidation
 Severely decreased carnitine palmitoyltransferase II (CPT II) activity (less than 10% of normal) in multiple tissues
 Absence of CPT II protein

Etiology

 lethal neonatal form of carnitine palmitoyltransferase II (CPT2) deficiency is caused by mutation in the CPT2 gene )MIM.600650)

See also

 CPT deficiency type 2 infantile (MIM.600649)
 CPT deficiency type 2 late-onset (MIM.255110)