CPT-I deficiency

Inherited CPT-I deficiency affects only the fiver, resulting in reduced fatty acid oxidation and ketogenesis, witfi fiypoglycemia. CPT-II deficiency affects pri-... 

CPT-I deficiency produces a fasting hypoglycemia due to impaired liver function as a consequence of the inability to utilize LCFAs as fuel. 

The answer is D. The most likely diagnosis in this case is CPT-II deficiency, although this is apparently a fairly mild case. The patient s muscle weakness and brown urine (myoglobinuria) are characteristic of this disorder. CPT-I deficiency would most likely manifest as liver dysfunction. A secondary form of carnitine deficiency due to exogenous factors such as malnutrition, infection, or dialysis, is unlikely. MCAD ordinarily manifests within the first 3-5 years of life. The patient s normal stature is inconsistent with Marfan syndrome, which is characterized by tall stature and very long bones in the extremities. 

Clinical problems related to fatty acid metabolism. Deficiencies in carnitine lead to an inability to transport fatty acids into the mitochondria for oxidation. This can occur in newborns and particularly in pre-term infants. Treatment is by oral carnitine administration. Carnitine palmitoyltransferase I (CPT I) deficiency primarily affects the liver and leads to reduced fatty acid oxidation and ketogenesis. CPT II deficiency results in recurrent muscle pain, fatigue and myoglobinuria following strenuous exercise. 

CPT-I deficiency (liver and muscle types) 255120 600528 601987 Carnitine palmitoyl transferase I <1 100,000 Liver disease, hypotonia, renal tubular acidosis AFLP... 

Palmitoyl- CACT deficiency, CPT type II deficiency, VLCAD deficiency, LCHAD/TFP deficiency CPT type I deficiency ... 

Tein, I., Demaugre, F, Bonnefont, J.P. Sauddubray, J.M. (1989) Normal muscle CPT 1 and CPT 2 activities in hepatic presentation patients with CPT 1 deficiency in fibroblastst. Tissue specific isoforms... 

Defects of fatty acid catabolism, with the exception of SCAD deficiency, generally have elevation of more than one characteristic metabolite. MCAD deficiency is characterized by accumulation of C6, C8 (mainly) and C10 l species. LCAD and VLCAD are characterized by accumulation of C14 l, C14 2 and (usually) C16 and C18 l species. LCHADD and TFP deficiencies are characterized by the accumulation of OH-C16, 0H-C18 1 and usually at least one of the other long-chain species C14 1, C16 and C18 l. The CPT-II and CAT (carnitine/acylcarnitine translocase) deficiencies are characterized by marked elevation of both C16 and C18 1, but not C14 1. Multiple acyl-CoA deficiency (MAD) has several different etiologies, including electron transferring protein (ETF) deficiency, ETF-dehydrogenase deficiency and riboflavin deficiency. Disease patterns vary considerably. In severe forms of the disorder, a generalized marked elevation of mxiltiple intermediates is observed. CPT-I should be suspected when both C16 and Cl8 1 are very low in whole blood, especially if free carnitine is normal or elevated. 

Hug, G. Soukup, S. Berry, H. Bove, K.E. (1989). Pediatr. Res. 25, 115A (Abstract) Carnitine palmitoyl transferase (CPT) deficiency of CPT II but not of CPT I with reduced total and free carnitine but increased acylcarnitine. 

Primary carnitine deficiency arises from inherited deficiency ofCPT-i or CPT-ii, both of which are rare disorders showing autosomal recessive inheritance. 

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