Sooner or later

Sooner or later

Researchers in Israel have reported myoglobinuria in an 8-month-old infant girl who carries two copies of the S113L mutation for CPT II deficiency. The common S113L mutation is usually associated with a later age of onset, especially when residual CPT II levels are above 10%. In this case, CPT II activity was 16%. The researchers conclude that the early clinical presentation for this infant is unique and may be due to other genetic factors.

A similar case was reported in 1992 by researchers at Hadassah University Hospital in Jerusalem. A 7-year-old girl diagnosed with the muscular form of CPT II deficiency had a history of severe recurrent muscle pain from infancy. However, at the time of the report the child had not experienced myogloburinia.

The first symptoms of muscular CPT II deficiency most often occur between 6 and 20 years of age, according to Jean-Paul Bonnefont, MD, PhD. However, a first episode of myoglobinuria has previously been reported as early as 4 years or as late as over 50 years.

In 17 cases reviewed by Salvatore DiMauro, M.D. in 1980, myoglobinuria occurred before the age of 15 years in 8 patients, and before the age of 5 years in 2 patients.

An ongoing Spiral Notebook diagnosis survey is currently reporting that 35 of 50 patients had symptoms before age 14.

ANOTHER EARLY CASE

Researchers in Italy report a new mutation in a child with periodic muscle pain and myoglobinuria caused by fever. The child carries one copy of the common S113L mutation and one copy of a newly identified mutation known as E489K. Conclusion: "This case enlarges the spectrum of mutations in patients with CPT II deficiency and confirms the association of the S113L mutation with the muscular form."

Reference: Bruno C et al. J Child Neurol 2000 14(6):390-3

"Adult" form of muscular carnitine palmitoyltransferase II deficiency: manifestation in a 2-year-old child. Gempel K et al. Eur J Pediatr 2001;160(9):548-51

Antenatal presentation of carnitine palmitoyltransferase II deficiency Elpeleg ON et al. Am J Med Genet 2001;102(2):183-7

AGE AT ONSET
Muscle CPT II Deficiency	8 months to 50+ years of age
Lethal Neonatal CPT II Deficiency	Birth to 4 days old
Severe Infantile CPT II Deficiency	6 months to 2 years of age
L-CPT I Deficiency (Hepatic)	Birth to 18 months of age

References:
Hurvitz H et al. Pediatr Neurol 2000 22(2):148-50
Schiffmann R et al. Neuromuscul Disord 1992:2(4)285-8
Bonnefont JP et al. Mol Genet Metab 1999 68(4):424-40
DiMauro SD. Handbook of Clinical Neurology 1980 41:175-234

For more about the forms of CPT deficiency that affect infants, visit Family matters.