SLC22A5 mutations in a patient with systemic primary carnitine deficiency: the first Korean case confirmed by biochemical and molecular investigation.

Abstract

Systemic primary carnitine deficiency (CDSP) is a rare autosomal recessive disorder that presents episodic periods of hypoketotic hypoglycemia. The main symptoms of CDSP are skeletal and cardiac myopathy. CDSP is caused by a defect in plasma membrane uptake of carnitine, ultimately caused by the SLC22A5 gene. We report the case of a Korean patient with CDSP. He had an abnormal free carnitine level of 5.56 μmol/L (reference range, RR 10.4~87.1 μmol/L) and a palmitoylcarnitine level of 0.27 μmol/L (RR 0.5~9.7 μmol/L) in a newborn screening test. The patient showed an ammonia level of 129.4 ug/dL (RR, 25~65 ug/dL), a lactate level of 4.5 mmol/L (RR, 0.5-2.2 mmol/L), and a free carnitine level of 10.3 μmol/L (RR, 36-74 μmol/L) in blood. After PCR-sequencing analysis of the SLC22A5 gene, the patient was found to be a compound heterozygote for c.506G>A (p.R169Q) and c.1400C>G (p.S467C) mutations. These missense mutations are reported previously. The patient was started on L-carnitine supplement after CDSP diagnosis. The patient was treated with L-carnitine to reach a normal free carnitine level and has remained asymptomatic up to the current age of 21 months. The plasma free carnitine level normalized to 66.6 μmol/L at 4 weeks after treatment. To the best of our knowledge, this is the first report of a CDSP patient confirmed by molecular genetic investigation.

• Authors: Young Ahn Yoon, Dong Hwan Lee, Chang-Seok Ki, Soo-Youn Lee, Jong-Won Kim, Yong-Wha Lee, Hyung-Doo Park
• Journal: Annals of clinical and laboratory science (Ann Clin Lab Sci) Vol. 42 Issue 4 Pg. 424-8 ( 2012) ISSN: 1550-8080 [Electronic] United States
• PMID: 23090741 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Organic Cation Transport Proteins
• SLC22A5 protein, human
• Solute Carrier Family 22 Member 5
• Lactic Acid
• Ammonia
• Carnitine

Topics

• Ammonia (blood)
• Base Sequence
• Cardiomyopathies (blood, drug therapy, genetics)
• Carnitine (blood, deficiency, genetics, therapeutic use)
• Humans
• Hyperammonemia (blood, drug therapy, genetics)
• Infant, Newborn
• Lactic Acid (blood)
• Male
• Molecular Sequence Data
• Muscular Diseases (blood, drug therapy, genetics)
• Mutation, Missense (genetics)
• Organic Cation Transport Proteins (genetics)
• Polymerase Chain Reaction
• Republic of Korea
• Sequence Analysis, DNA
• Solute Carrier Family 22 Member 5
• Treatment Outcome